Making Head gaskets Last on my Subaru
Subaru head gaskets are about as hot of a topic as national health care lately. If you own a Subaru you know what I mean.
Since the 2.5 liter Subaru engine was put into production there have been thousands of head gaskets replaced across the country. We’ve done a good portion of those ourselves. In another post I’ll go into further detail about the details of Subaru head gaskets but for today I would like to offer some suggestions on how to help prolong the ones you have.
Subaru head gaskets can fail for numerous reasons. Failure of sealant, improper torque, surface imperfections in the cylinder head or engine block and of course heat or excess heat.
I’m going to focus on excess heat. Within the engine block the coolant is circulating to keep the engine cool due to internal combustion occurring. The coolant remains in contact with the metal and is able to absorb heat, travel to the radiator and release the heat to the atmosphere.
Two important things must occur to for the coolant to do it’s job. It must have adequate flow to move the heat away from the internal areas of the engine and it must remain in contact with the areas it’s trying to cool.
There are 3 very important items that may individually have a negative impact on the coolant’s ability to do it’s job. If all 3 components are bad or inferior, problems could develop even sooner.
Subaru Radiator Cap
Radiator cap:
Keeps coolant in a sealed system, allows overflow to exit and return as coolant expands and contracts, but most importantly it raises the boiling point of the coolant in the system by keeping the cooling system pressurized. Most radiator caps for stock vehicles keep the system pressurized between 13-15psi. This can raise the boiling point depending on the mix of coolant/water an additional 35-40 degrees. A 50/50 mix of anti-freeze and water has a boiling point around 265 degrees. Add to that a radiator cap that holds 13psi and now you have coolant that won’t boil until 300 degrees .
There are areas throughout the engine where the coolant circulates that become very hot. So hot that it can boil coolant. Since we must have the coolant in contact with the metal to perform it’s heat transfer duties we now have a problem. Scenario: Radiator cap is weak (which we run into all the time on Subarus). A weak radiator cap not holding pressure may not let all of the coolant get hot enough to boil but there are areas within the engine that are now boiling. Boiling coolant has air bubbles that now keep the coolant from contacting the cylinder walls and other extremely hot areas within the engine. This heat is more than the engine and gasket were designed to withstand on a regular basis and thus a situation that will accelerate the failure of the gasket.
Flow of the coolant is important also. To keep from boiling the hot coolant must be quickly moved away from the hot cylinder walls up to the radiator so it can release it’s heat. Below is a picture of a Subaru water pump and also a quality Japanese aftermarket water pump. Although we for the most part believe in genuine Subaru parts, here’s a case where genuine Subaru part’s may not be the best choice. Note the stamped steel vanes on the Subaru pump vs the quality cast and machined impeller on the Japanese counterpart. The tight clearances and defined impeller vanes are very efficient at moving coolant through your Subaru engine. (an interesting side note that older Subaru water pumps were made nearly identical to the pump on the right).
Genuine Subaru Water Pump VS Aftermarket Japanese Water Pump
Another important part of keeping the hot coolant flowing out to the radiator and away from the internal hot spots in the engine is a high quality thermostat. I’ve shown below the comparison between a generic aftermarket brand on the left and a genuine Subaru thermostat on the right.
Aftermarket Thermostat VS Subaru Thermostat
Note the Subaru version has a much larger spring, larger diameter central area for coolant flow and is made of steel and brass. The generic brand contains copper, a big no no with Subaru. Subaru actually states that copper in a Subaru cooling system is ill advised and may cause excessive electrolysis and corrosion.
Even after trying to be dilligent about providing the best possible cooling for your Subaru you still may need to cross the head gasket bridge some day. If you ever get to that point, Smart Service will have a solution for you. We now offer new and improved aftermarket head gaskets which we believe will be the last ones your car will ever need. I’ll make a future post with more details about their construction.
Cheers,
Mike
I Like your site a lot. I have a 98 Forester with 170K miles that has been blowing coolant thru the reservoir for about a year. At first I had to add 1/2 gal. every week or so. Now its every other day. Temp sometimes rises close to red hot, but still the engine runs smoothly, no smoke, just coolant loss. Is there still hope for this engine? What about the chemical gasket fixes? My regular mechanics want to replace the engine($4000K)but I don’t have that kind of money. Will gasket replacement lead to discoveries like warped heads, etc? Help! George
Hi George,
Thank you for the question about your Subaru head gaskets. I’m sorry to hear of the situation.
Based on the many Subaru engines we’ve seen with this issue I think it is a strong possibility that if you disassemble the engine you will find warpage in the cylinder heads and engine block deck from hot exhasust gasses and overheating instances. Also the fact that the engine has 170k on it would also increase the odds of finding cylinder wall wear that would lead to replicing the block. Your description leades me to belive that the engine is in the later stages of head gasket failure. Subaru’s engine block and cylinder heads are aluminum and are more suseptable to damage from overheating than a cast iron engine.
Here’s the thought process we suggest when dealing with an obvious failure of Subaru head gaskets, especially when there is a strong possibility that the engine will be damaged beyond an economically sensible repair.
Do you still love your Subaru? If the answer is yes and it still meets your needs, then we anaylize the following. (0thwise now is the time to make the move into your next Subaru).
What is the condition of the rest of the Forester?
An overall analysis of all mechanical aspects of the your Subaru plays an important part in deciding whether to fix it or not.(this applys to any Subaru in need of a large repair) If it has few needs or issues, then it still may make sense to fix it, even if you have to spend 4k on a new engine. It still may be worth it compared to having car payments for the next 5 years plus a down payment to cough up. (make sure what they are suggesting really is new… some shops refer to used engines as new since they are new to the car… make sure of what you’re getting).
Now, if the vehicle inspection reveals there are many other problems with the car, now is the time to cut your losses and move on.
If one decides to move forward on the repair, the next step is to remove the engine, disassemble it and evaluate it’s condition. If the engine block is warped or damaged from the exhaust gasses burning the aluminum it will be necessary to replace the engine block. This can certainly push the repair into the $4k range and sometimes above depnding if any other items are included at the same time such as additional seals and gaskets, water pump, timing belt pulleys etc. I suggest being prepared for a worst case sceneario. If an engine isn’t needed then life is good and the Forester lives on for much less than expected. If not, you end up spending the larger amount of 4-5k and your Subaru Forester has a new lease on life.
As far as being sensible compared to “blue book” value… You’ll probably be spending about what the car is worth so look at it like you’re re-investing in your Subie in the hope of getting another 5+ years of trouble free transportation.
Another note… a shop disassembles your car, they discover the worst, and you decide not to go further, you’ll be left with an engine in pieces and a bill for the removal and dissambly of the engine.
As far as chemical fixes, I’ve never seen any work in this instance. The size of the failed spot in the head gasket is usually far larger than a chemical can repair. Subaru did offer a sort of chemical repair for head gaskets that were dripping coolant externally. I’ve seen it work for some cars and not for others. I’ve never seen it resolve an internal leak where combustion gas is being pumped into the coolant.
good luck,
Mike
I have a ’98 Subaru that I bought in ’05 as the third owner. I had it checked before I bought by a Subaru specialized shop in Boulder, CO. Everything checked out at the time. I drove it back to my parents house in Aspen, CO where I lived for two years, while getting a foot in my profession. The motor started leaking oil, I was told by the mechanic, due to a leaking cam shaft. As a result of the costs I was told it would take to repair, I decided to put a newer (used from Japan) motor into it. I’m now about 2 years down the road and am being told the motor I put into the car is a ’96 with hydrolic lifters, and now blown headgaskets. I’m looking at having the headgaskets replaced, but don’t have the money to do it, and don’t have the freedom not to drive it, as it is the daily driver to and from work. The engine has yet to over heat, and I’m told that is a good thing, but it’s only a matter of time. I trust the mechanics I have been taking it to, and know they aren’t just blowing smoke. I’m wondering if you would say it’s worth while to invest the money into repairing the motor that’s in it, or any suggestions you might have. Thank you for your time and consideration. And if you have any need for more information on other symptoms the car is displaying, I’ll be happy to share.
Dave
Hello Dave,
I’m sorry to hear of your dilemma, espescially the problems and expenses leading up to it. After reading your post I think your best option may very well be to repair the current engine. Since I don’t know how bad your head gaskets are or how they were diagnosed I really can’t tell you how soon to get them done. Just because the car isn’t overheating doesn’t mean it isn’t doing damage to the engine. If even the slightest bit of coolant seeps into the engine cylinder it can begin to damage the cylinder wall.
The 96 hydraulic lifter engine was overall a very good 2.5 for Subaru. If they do replace the head gaskets, make sure they evaluate the cylinder conditon, the head and block surface, and all the other surrounding parts like water pump, timing belt tensioners and idlers, seals etc.
The other factor to consider is the overall condition of the Outback. If, other than the head gasket problem, the rest of the car is in good shape with no immediate needs it would be a good investment. If the car is riddled with surrounding problems that are going to cause you to put large amounts of additional money into the car within the next 12 months then it may be time to either drive it into the ground or sell/trade it.
Good luck with your Subaru whatever you choose!
Mike Corbin
Smart Service
Hi Mike
I have a 2002 Subaru Forester. I bought it in ’04 off-lease when it had 48K on it. I was not concerned about the high mileage since I walk to the train for work; since then I’ve only put about 8K a year on it. Now it’s at 98,000 miles.
Over the past couple of years, everything has seemed to go wrong — in 2008 I had to replace the center pipe (exhaust donut)and that gasket/nuts/bolt assemblage due to leak. At my next service, they replaced the oil pump o-ring and resealed the pump. Spring of 2009 it was the rear catalytic converter shields, which were cracked.
(I am not including “normal” stuff, like my battery, timing belt, and F/R brake jobs, the repairs and replacement of which happened when one would expect.)
I just took it in for service and they told me my head gasket had an oil leak (NOT a coolant leak). I was also told it was something I wouldn’t notice myself since the oil wasn’t hitting the ground, i.e. no tell-tale spots on the driveway or anything. Expensive repair, as you know. I asked how urgent it was, and the service dept said I could get through ’til spring as long as I keep an eye on the oil level.
This is the thing: I have religiously followed the Subaru maintenance schedule for service; my last one was September. But every time I go in there’s another major repair, and it always an expensive problem.
Should I get a second opinion on this? I guess I find it interesting that they specified *oil* — in other words, I have the gasket problem which isn’t covered by warranty. Plus, it just seems like I’m getting nickeled and dimed on this car, which is amazing to me on an ’02 model with less than 100K on it. Do I start looking for a new vehicle? Or a different Subaru service department?
Mike,
What make of water pumps do you suggest for 99 OBW 2.5L DOHC?
I can find ones made by Bosch, NPW, and Paraut (claim to be OEM). The one by GMB is similar to the stamped impeller shown as OEM.
http://www.partsgeek.com/catalog/1999/subaru/legacy/cooling_system/water_pump.html
Planning for TB change and wonder what supplier you use for your Subaru Water Pumps. Bosch name is familiar and appears to match you photo. Any comments?
Thanks!
Hello Mike,
My 1999 Subaru legacy outback had the head gasket problem and repair in 2005. Now(2009) at 140, 000 + miles, it is working fine. I love my car. But am thinking it won’t go another 75,000 miles and should get another one. Do you have any advice?
thanks.
Hi Iian,
I think first I’d like to comment on your exhaust. Subaru makes a good exhaust system but depending on where you live rust can be a big issue where they salt the roads for snow. Up in the Seattle area the exhausts just about last the life of the vehicle (as long as the catalytic converter doesn’t wear out). Also lot’s of short trips can rot an exhaust system from the inside out much quicker because of the moisture inside the exhaust never fully evaporates. (you’ll notice vapor and water drips off your tailpipe when your car is warming up).
As far as the head gasket question, I think from your attention to detail keeping your Forester serviced it should be a good car for miles to come. The oil leak is somewhat of a concern but from the sounds of yours it may be quite a while before you have to address the issue. My concern is if you have any coolant leaking from the same area. If your coolant level has remained steady you’re probably fine. That area of the head gasket may go a few years or less than a year. It’s tough to tell. The one thing I’ve learned about that particular engine is that eventually you will have to replace the head gaskets. The key is to save ahead of time and make sure it’s done at a quality shop. In the mean time it wouldn’t hurt to get a second opinion. If it’s a light leak, they may just advise you to monitor it until it becomes bad or until coolant starts making it’s way out.
Good luck,
Mike
Mike,
Go with the Paraut. When you compare it to your Subaru water pump you’ll see the difference in quality. That’s what we use.
good luck,
Mike
Hi Catherine,
Keep driving!
Your Subaru sounds like it got the tlc it needed when they replaced the head gaskets last time. If they haven’t failed by now there’s a good chance you’ll get another 75k out of it. I’m guessing you’ll have other repairs like small leaks, and other extraneous repairs but I’m guessing the head gaskets won’t be one of them.
My second reason to keep driving your Outback is that by now a 1999 Outback with 140k on it isn’t valued that high blue book anyway and you’ll get way more value out of it driving it vs. selling or trading it in. You’d probably get the same for a trade in even if the head gaskets eventually did go.
Take care,
Mike
Mike,
I wrote in a few weeks ago, and am preparing to have some major work done to my Subie. The mechanic I go to has diagnosed the problems of the car to be a blown headgasket in cylinders 1 and 3, a cracked CV boot on the front passenger side, and I need to replace the rear brakes and rotors. They told me I should be able to smell exhaust in the coolant overflow, and I check this weekend, but I can’t say I smell anything aside from coolant. On top of that, after reading what you’ve advised other folks, the coolant level is full in the radiator and above full in the coolant overflow box. The oil has been leaking for some time, from I don’t know where, they told me I have a warped separator plate and that drips onto the catalytic converter and that is why I can smell burning oil when the car is running, but it seems to be a small enough amount that it doesn’t require oil added on a regular basis, and I check the oil level every couple of weeks. The car is a ’98 Legacy, with a ’96 2.5L DOHC, I had to have it replaced as you will recall from my previous post. I love the car, and I figure I can’t buy a new car for the price of what they are asking to repair this car. The estimate is about $3400 to cover all parts, labor and taxes. That included all the parts to be replaced for the headgaskets, (i.e. coolant system, etc.) which is most of the expense (about $2400), the CV boot so long as it’s just the boot is about $300, and brakes and rotors is about $600. I trust the shop I go to, and I know the guys do the best they can without tearing everything apart to diagnose things. My question is this, what other signs should I be looking for that would indicate that it is a blown headgasket and not something else less major? I would really be upset if they get into it, and find that it wasn’t the headgaskets after all but rather something really simple like a dirty spark plug or something that was causing the check engine light to go on. Also, do you think the price they are charging is fair? Ultimately, I am wondering if I should just focus on the brakes, rotors, and CV boot for now, and let the headgaskets go for a while longer before getting them fixed? Thanks for your input.
Dave
Hi Dave,
It all sounds like a reasonable course of action and price. Failure of the head gaskets is best diagnosed by either visible coolant dripping from area of head gaskets or hydrocarbons are detected in cooling system. (an emissions gas analyzer is best used for this). The seperator plates do tend to leak and are good to do at the same time as the head gaskets due to some overlapping labor savings. I would want a definitive answer on what the exact failure of the head gaskets is. One can also pressurize each cylinder individually with compressed air (leakdown test) and monitor for bubbles coming out of radiator. No bubbles, no internal head gasket failure. (there are exceptions that only leak when warm or cold).
As far as the check engine light being related, maybe they are thinking of a valve problem that would be solved with a valve grind when the heads are off. More specifics would be helpful.
Good luck,
Mike
Mike,
I took my 2002 Legacy Wagon to the dealer for a scheduled oil change, and was told I needed new headgaslets, fuel pump , timing belt. I’m wondering about the gaskets since it was done at 58000 miles.(I now have 92000miles) I wondered if this is usual and if Subaru could bear some of this cost of the new headgaskets again. I didn’t notice anything different about my car this time since it is not leaking in my garage or any warning lights, but they told me it was a major problem that needed immediately done. I am taking the car in tomorrow and the cost is $1500. What do you think? thanks
Hi Suzie,
The price if doing just the head gaskets is reasonable. I am wondering the same thing as you, why did hey already fail again and what kind of failure is it? Also, not sure why the fuel pump is being included. Having head gaskets fail multiple times if the job was done at the dealer might qualify from some help from Subaru corporate. I would call 1-800-SUBARU3 and explain your situation to them. It may go nowhere but I’ve also heard instances where Subaru has reimbursed people in special cases.
Good luck,
Mike
I have a 1998 Subaru Forester with 146K miles on it. Up until three weeks ago it was fine, having required very few repairs over its life [axles, rotors, that's about it.] But it began running hot at speeds over 50, and after replacing the radiator to no avail, my mechanic tells me that, in all likelihood it’s the head gasket. He recommends I consider replacing the entire engine with a used, low mileage one with a warranty. While it costs a little more than doing the heads [$2K vs $1.5K], there are fewer old parts to break down. The only downside is the risk that a new engine will put pressure on an old drive train and transmission, leading to more costly repairs. I have to decide over the next week or so whether to repair a 12 year old car, or buy something new, as not being able to do highway driving is a problem. While I’d love to get a new car, I can’t afford it right now. I’m tempted to get a new engine and hope I can get a few more years out of the car, but I’m wondering if it’s throwing good money after bad. Thoughts?
Hi Mike,
As many others on this post I am having a headgasket issue on my 04′ Forester. The engine has 125K in mileage. I was recently told by my mechanic the right bank headgasket is leaking oil. He stated I should keep an eye on the oil level for now and watch out for coolant consumption and/or leaking. I was advised they would have to pull the engine out completely to replace both headgaskets and the cost to be $1200 to $1500 depending on any other issues found. I know at some point I will have to go through the process, however is it really necessary replacing both headgaskets at the same time? The left side is bone dry with no issues. I was told the right side is known to be a problem. Any reasons why the right over the left? Thanks for any advice/comments you may have.
Cam
Sorry to hear of your Subaru problem. The Forester drivetrain should have no problem handling a newer engine, even a brand new engine if money were no object. If you do get a used engine I recommend replacing the known weak components before you install it into your car. It can be a great long term fix (assuming it’s done correctly) with some short term hits to the pocket book. The parts I’d recommend are the head gaskets, the front and rear seals, the timing belt and possibly the waterpump and timing belt tensioners depending on their condition. This could up the price a bit further but if the rest of the Subaru is in good shape it could get you another 100k with regular repairs and maintenance along the way. This could end up saving quite a bit in the long run compared to buying a new Subaru.
Good luck,
Mike
Hi Cam,
Your Forester may not need head gaskets as soon as you think. If you have no loss of coolant or no visible coolant on the head gasket area and it’s just oil it may be OK for now. If the oil is residual and not a drip it may take quite a while before it develops into something more serious. Also, it’s the left side that tends to be the problem gasket. We advising doing both at the same time once you decide to do the gaskets because of the labor savings while everything is disassembeled.
I would say for now, monitor the oil and coolant level until the next oil change and if there is no loss of either then just have a visual inspection done to make sure it’s not getting worse. It may be at the stage where we’d advise a Subaru owner to monitor until it worsens. (which can be 3 months or 3 years). The fact that the predominant failure side is bone dry is a good thing.
Good luck in your Forester
Mike Corbin
I’ve been smelling burning oil on a 1999 Subaru Forester I recently purchased. Today while looking for an oil leak with the engine running, I discovered a small amount of a thick black oil around the Driver’s side head gasket as well as some coolant drops.
How long can we drive the car like this? We have only had it a very short time and did purchase an extended warranty, but I am not sure if the warranty has kicked in yet. The car only has 65,000 miles on it.
I’m wondering about the timing belt and water pump as well. I do not think these items would be covered on the ext warranty, but would like to know what is a fair price to pay to have these done.
Thanks!
Rick
Hi Mike,
The short block on my 2002 subaru forester engine was replaced recently. Someone told me in order to do that the mechanic would have to chnage the headgaskets too. Is that true? I appreciate your feedback.
Tom
Yes, you must install new head gaskets during a short block replacement.
Mike
Hi. Very useful site, thanks for setting it up. I am considering buying a Subaru Forester for my son to take to college in the snowy Midwest (Iowa). And I have been reading about the head gasket issue. Pre-2005 Foresters are significantly cheaper than post-2005 Foresters, presumably both because of overall aging and the headgasket issue being more serious for models before 2005. I have found a 2002 Forester with 85K mile for a reasonable price at a Subaru dealer who took it in trade because the previous owner did not want to deal with the HG problem. Their service dept immediately replaced the head gasket and did some minor repairs. The question is, how well do engines with the replaced head gaskets perform? Is it likely we will get a a few years before having to do the job again? Note that when we lived in Australia 1997-2005, we drove a 1992 Liberty sedan up to 200K miles (and then sold it for $2500) , with an engine overhaul (oil leaks etc) around 140K. Thanks in advance for your help. JHH
I’m a firm believer that if a head gasket job is done with care and precision that it may never need to be done again. The later generation Subaru gaskets held up fairly well although there have been some aftermarket brands that appear to be lasting even longer.
If the job was done right I’d have confidence that you’ll get many many miles out of the Forester.
Take care,
Mike Corbin
Independent Subaru Expert
Mr. Corbin
thank you for posting this blog.
2000 legacy 245,876 mi original owner.
i am DIY mech. i do as much of the work that i can. but i have reached the end of my rope. last spring i replace the timing belt by myself (second time). by oct/nov 2009 the water pump went. ( it was the OEM. 225,000 mi) replaced it but was still having leaking issues. mild one off the water pump itself i did not get the seal right. this spring i started to have issues with the cooling fans running constantly. Replaced the Engine coolant temp sensor which fixed the poor idle on cold start ups; but not the fan problem. i have replaced Rad cap and the thermostat with quality after market parts. fans still engage and stay on unless i’m moving at hi-way speeds. then only the primary fan runs . once i stop and idle the secondary fan kicks in. i just replaced the water pump gasket with an OEM style and inspected the inside of Radiator(clean no contaminates) but the issues still is the fans engages. the fans only operate after about 45 min of driving ; and problem will stop if i let the engine cool for about 10 min. i added the coolant supplement to cooling system per SUBARU TSB. I can smell no coolant at the tail pipe but i have a small oil leaks under the block right side. i have no oil in the coolant and coolant in the oil that i can detect. cold engine at start up and i do not get any large bubbles at the filler neck.
what can i do next to diagnose the fan issue. or what is the next step.
once again thank you for this web page and i wish you were in the Washington D.C. area.
Give us a call at 1-866-417-0880 and we can give you the part number and or sell them to you directly.
You will normally only find that they are available at a Subaru independent repair shop.
Mike
Hi Garth,
Before going too much further I would advise you find someone with an emissions exhaust gas anaylizer.
These are very proficient in diagnosing Subaru head gasket issues. An unsolvable overheating condition can many times be the result of exhaust gasses pushing into the cooling system and creating air pockets. (exhaust pockets).
As these air pockets move around within the engine they can cause strange things to occur includint overheating.
We recommend that a person hold the test hose of an emission anaylizer over their radiator neck and coolant recovery bottle while watching the hydrocarbon reading on the anaylizer. If the Subaru has a blown head gasket you will se the HC’s climb. Zero is the reading you want to see.
Last but not least, a simple thing that can get some Subaru DIY’s is bleeding the cooling system properly.
As long as your thermostat has a bleed hole in it you should be able to slowly fill the radiator while the bleed screw on the other end of the radiator is removed to burp out air pockets. Running the Subaru after doing this with the radiator cap off will purge out a few more pockets but most will be gone if the above procedure is followed. If the thermostat is aftermarket and doesn’t have a bleed hole, it may be difficult to bleed out the air.
Good luck with your Subaru!
Mike Corbin
Smart Service
Hi Mike,
so happy to come across this website as I am having just about every issue mentioned above or have already fixed…(basically been their done that stage) with my 98 Forester. So here I am already put a used engine in a month ago. The guy who fixed it said the engine would have a loud tapping sound until I drove it awhile and the oil works it’s way through. He said the cause is the engine sitting waiting to be put in a car.. Is there anything I can do to make the sound stop. My brother said I mite be able to have it adjusted but he said he was unsure with this being a 98. I would have thought if it could be done the guy who fixed it would have, but I keep hearing comment’s about them not wanting to bother with it. So if you say it can be adjusted I will take it else where. I just need enough time to drive it and save what I already put into it and it’s gone.. Thank you, M
MaryAnn,
It depends on what the loud tapping sound is on your Subaru Forester.
If it is a tapping sound that goes away after 10-15 minutes as the car warms up, don’t worry it’s normal. It’s a sound that occurs because of the pistons slapping against the cylinder walls until they warm up, expand and reduce the clearance between the piston and cylinder wall. I have yet to see a Subaru engine fail because of this noise.
It may also be a valve that is misadjusted. One can listen with a stethescope to see if it’s on the outer reaches of the engine. If so you may need to check the valve clearance.
The other tapping sound can be the result of worn internal engine components. If it’s there all the time, it could also be a failing rod bearing, piston wrist pin or main bearing.
I would definately have another shop at least evaluate the noise.
Good luck,
Mike Corbin
Independent Subaru Expert at Smart Service
Mike,
Myself and my mechanic friend are at our wits end! We are located in Florida but I came across your website and am seriously hoping you can help. I have a 98 Outback Legacy wagon. The car won’t accelerate even if you “floor it” from a complete stop but if you shifted it into 1st gear and manually shifted it would “go” and then once it got up to 25/30 MPH it rode just fine and shifted fine. But as soon as you had to stop at a light it would bog down again and the whole scenerio started over. Someone mentioned the Mass airflow sensor? Scott (my friend) said that the fuel injectors were very dirty. He cleaned these but that didn’t help much. After doing this he noticed that the car wouldn’t continue to run it almost sounded like it was out of gas (which it wasn’t) I’m hoping you have some idea what it may be. I really could use some of your expert advice. Thank you in advance.
I would need a bit more information on what you’ve done so far. If the plugs, wires and coil have been eliminated as possibilities, the MAF Sensor may be the culprit (especially if it has a “160″ for the last 3 numbers in the part number). Does the check engine light ever illuminate, or are there any resident codes in the memory?
If it were a MAF sensor, a person should be able to monitor it’s function with a scan tool and verify that it’s signal to the ECM is erroneous when the symptom occurs.
Good luck with your Subaru!
Mike Corbin
Independent Subaru Expert
Smart Service
Hi Mike, We bought a subura forester 2001, with 112,00 miles on it , owned by 1 owner,and carfax had all the service work , and was always service on time as well as preventive maintance , there is a sticker under the hood that says something about w something 80 service campaign service done in 2002 a year after the car came out in 2001 . i was told this had something to do with the recall of the headgaskets, now does this mean they recalled it and they fixed the headgaskets , or they put something it them to seal the gaskets ? i took it it not to long ago cause the check engine light was on , they told it was the cat , so i had the back cat replaced , cause they said thats the one that usally fails , have had a problem since, but the mechanic said he had to flush the radator , and put some subaru head gaskets sealant. it really hasnt leaked any anti freeze , no sign anyways , but he said to keep a eye on loseing anti freeze , at this year do i have to have the head gaskets replace??
Hi Keith,
The service campaign sticker under the hood of your Subaru Forester probably refers to the “Coolant Conditioner” campaign that Subaru did on many of it’s models. In short, you were asked to come into the Subaru dealer so that they could add this “Conditioner” to the coolant. Once the coolant conditioner was done, Subaru would then extend the warranty on the vehicle’s head gaskets for 8 years or 100,000 miles for external coolant leakage only. Once past on time or mileage the warranty would expire.
At first Subaru recommend that only specific years of their vehicles should get the coolant conditioner added when changing coolant on a Subaru. They then came out with a subsequent bulletin recommend the addition of the conditioner to all Subarus when the coolant was changed.
In short, it seems to contain some kind of aerobic “stop leak”.
The negative outcome of the additive could be more plugged radiators and heater cores down the road.
As far as whether to replace the head gaskets yet, I see no need to replace them as long as they are still holding up.
Take care,
Mike Corbin
Smart Service
Independent Subaru Expert
MR. Corbin…
once again thanks for the site. after much hair pulling and 2800 dollars i have had the head gasket replaced by a local Subi shop. here is what i learned after replacing many parts.
Yes The head gasket was ( not HAD) failing. oil was entering the cooling system. as i was chasing the issues with new parts the cooling system was “tightening up”. the Subi shop was as stumped as i was because of know tell tale signs of blow head gasket were not present. what was causing the engine fans to run all the time and the wild temp swings was because the oil was congealing and cloging the cooling system. most of the sludge was in the radiator. the shop was truly amazed that the car had 250,000 miles when the gaskets went. you can see were the gaskets failed both almost in the exact same location. i hope this blog helps future customers make a educated guess.
P.S. i would have done the job my self. but when the manual tell to remove the Cams… that is were i threw in the towel.
Thank you for your input on your head gasket issue. I have not come across that scenario yet in either of our shops where oil is entering the cooling system (although I have seen coolant making it into the oil in a couple of cases).Just one more thing for the Subaru owner to be aware of when diagnosing an overheating condition.
Cheers,
Mike Corbin
Smart Service
Independent Subaru Expert
Mike,
I have a 1996 Subaru SVX with 74K miles on it. I bought it from the original owner. It was a southern car so it looks pretty clean and solid. The only issue is that the temperature gauge fluctuates slightly from low (30-35%) to normal (40-45%) as I drive it. The temp isn’t random but does seem to correlate with the driving conditions. I didn’t see any evidence of coolant in the oil or oil in the coolant. I don’t see white smoke from the exhaust. The coolant level in the overflow tank will go from just above “L” when cold to just below “H” when warm. I am getting the thermostat and radiator cap changed today and they will do a flush. What are the odds that I have a head gasket issue. I have been told it is rare for the H6 engines but others say it is inevitable with age.
From your description of your temperature fluctiation you may have nothing wrong with your SVX. The coolant recovery bottle seems to be functioning as designed. Your thoughts to change your thermostat are a good logical start. We rarely see head gasket issues on the Subaru SVX or any of the H6′s for that matter. Once you change the thermostat, it would be interesting to monitor the coolant temperature with a scan tool to see when the cooling system fans kick in and when they shut off. It would also be interesting to see if the temperature on the scan tool correlated with the temperature on the dash. When eliminating possibilities, don’t forget to include the temperature gauge and temp sender in the process.
A final test of the cooling system with an emission analyzer should also confirm the head gaskets are ok. If there are no hydrocarbons in the cooling system and no external leaks, they should be fine.
Good luck,
Mike Corbin
Smart Service
Independent Subaru Expert
Thanks Mike. I just recently discovered the “dead zone” in the temperature gauge. I never realized that they were designed to sit dead for a range of “normal” temperatures and only move when the temperature was too cool or too hot and outside of this normal range. Now that I know that, the temperature sender is a logical thing to change. I suppose I should have done that before changing the thermostat and radiator cap. But I guess a coolant flush on a new-used car is a good idea and the other parts weren’t really too expensive so it wasn’t all for not. Tomorrow I swap out the sender!
One more question. Should the Subaru “conditioner” be used on the H6 engine or is the TSB only for the H4 engines? If not, is there any decent seal/gasket conditioner coolant additive out there worth using?
Subaru recommends the coolant conditioner be added to all of their vehicles at this time any time the coolant is changed.
Mike
Can the conditioner be added to the overflow tank if my mechanic missed it when filling the radiator?
By the way, my issues were due to the temperature sender. I guess the resistance drifted high over the years.
I would suggest sucking out some from the radiator itself then adding the coolant conditioner. If you put it in your overflow tank it may take a while for it to become dispersed throughout the engine.
Glad it was only a sensor issue!
Take care,
Mike Corbin
Smart Service
Independent Subaru Expert
Dear Mike,
I recently purchased my 3rd Subaru: 1996 legacy outback, 2.5l with 147,000 miles. The main issues are: it gets very bad gas mileage, @ 12 mpg, wires and plugs look pretty old. I was reading the previous owners maintenance paperwork and there was contaminated coolant in overflow bottle, which was cleaned and changed (2007). Then a year later there was a hole in the radiator hose, so they replaced it and then a month later “possible oil in coolant”, so they drained and refilled the radiator. I obviously should have checked this first or gotten an inspection, stupid move on my part. They also replaced the crank position sensor and the form says “advise on possible oil leak on rear main seal.” Yikes, I can’t afford all that labor -tranny removal, ect.
My question is, are the gasket/s blown or leaking internally? It passed smog with flying colors in July, right before I bought it. I have since changed the air and oil filters, oil change, radiator flush, fuel injection cleaning, and CV joints. There was sludge in the overflow bottle. The car wasn’t driven for over a year before I bought it, which I now know is bad for seals and gaskets. Everyone I take it to says if the CEL isn’t on, it’s fine. It doesn’t overheat, at least not yet and drives well, besides for the poor gas mileage problem. Should I try to fix this car, or is it a goner? BTW, I don’t have money for an engine rebuild or head gasket repair, but if there is anything I can do that will make it run longer that is below 4 figures, I would do it in a heartbeat. Also, I can’t sell the car ethically knowing there may be a serious problem with it. It’s a pickle… can you please impart some car wisdom for me Mike?
Mike,
My 02 Outback H6 VDC is in the independent shop right now. They replacing head gaskets because I complained about engine overheating and bubbles in coolant tank. I trust the mechanic but he is not a Subaru specialist and it a first time he disassemble Subaru H6 engine. He got head gasket repair kit, sent heads to machine shop and assembled the engine but noticed a small oil leak from head gasket area. He disassembled engine again, got original Subaru head gaskets
(he found no difference between first and second sets of head gaskets) and going to reassemble the engine again today. He told me that will will throw a towel if the engine leak will reappear and he is out of ideas about the reason for leak. He told me that Subaru do not use any sealant for head gaskets assembly – it’s just metal on metal. Have you heard about this or similar problems ?
Do you have any advise ?
Thanks!
I have not heard of an H6 leaking immediately after installing head gaskets. I agree with using the genuine Subaru head gaskets on that job and agree that they need to be installed with a perfectly clean surface and no sealant.
The only idea that I may have about the oil leak is to question the condition of the surface of the engine block itself in the area that the leak develops if this round doesn’t do the trick.
Good luck,
Mike Corbin
Smart Service
Independent Subaru Expert
Hi Morgan,
First of all, if you do have a head gasket issue going on with your Subaru, it may not be worth putting the additional time and money into chasing down the other problems based on your budget. A simple test is to have someone with an exhaust emissions analyzer sniff the contents of the coolant recovery bottle and radiator for presence of hydrocarbons.
If hydrocarbons are present then this confirms either a failed head gasket (most probable) or worse, a cracked head or block (unlikely).
It may be the type of vehicle that makes sense to repair if you can do the work yourself but if you are paying a shop to do it all it may blow your budget.
Good luck,
Mike Corbin
Smart Service
Independent Subaru Expert
Mike, what’s the price range for engine block of H6 outback resurfacing and how can i find machine shop who does the job?
I got a quote for $750 and it seems too high. I am in San Francisco Bay area.
Hi Dan.
I believe that price may well be within the reasonable range. To surface a Subaru engine block, the block must be fully disassembeled, all the way down to the crank. Once the case halves are empty, the machine shop can then resurface them.
Take care,
Mike Corbin
Smart Service
Independent Subaru Expert