Common Subaru Oil Leaks

Where does my Subaru Leak oil?

Most likely you know about the 2.5L SOHC head gasket leaks. They’re an external oil and/or coolant leak. This article is to target the other common oil leaks that your Subaru will eventually come up with. There are a few other areas that these vehicles like to leak, but after these are taken care of these vehicles are pretty bullet proof in my opinion. I’m going to list these areas and then explain a bit about each one.

The common Subaru oil leak problem areas are:

  1. Rear of engine, PCV baffle plate
  2. Front of engine, crank seal and piston access plugs
  3. Valve cover/spark plug tube seals

Well, of course there are other areas that leak oil but, as of my years of experience working on Subaru’s I would have to say these are the most common oil leak areas. Also need to point out that the spark plug tube seals are only a problem on the 2.5 SOHC and the 2.2L SOHC second generation engines.

Subaru 2.5L SOHC Spark Plug Tube Seals

Subaru 2.5L SOHC valve cover spark plug tube seals are very common to leak. They will cause problems and you won’t even be aware of the leak. The reason for this is because they leak into the spark plug tube and take a long time before the oil works it’s way out to an external leak that you will notice. The problem with this is the oil will contaminate your ignition wires and spark plugs and cause cylinder misfires. Subaru misfires are not a good thing as those catalytic converters are very expensive. If you don’t know why I referred to the catalytic converters, this is because cylinder misfires are the number one cause of pre-mature catalytic converter failure. With that being said, just pop out your ignition wires on all four cylinders and check the tubes for oil. You really don’t even need to look into the spark plug tube; if they’re leaking it will be all over the ignition wire that you just removed. It’s pretty obvious and I’m sure if you were not a mechanic you would pick up on this pretty quick. The driver’s side is harder to get to so check the passenger side first. If you find those leaking you’ll be replacing them as a set, so no need to check the other side.

Subaru Baffle Plate

The baffle plate or PCV baffle plate is common to leak and on the older engines they have used a plastic cover. This is a common problem area so Subaru has updated the plate to steel with Allen head bolts instead of Phillips screws. Only use the updated part if your plate is plastic. Some of the early and late MY 2000 Subaru’s have used an aluminum one from the factory and in my opinion these are the best one, except they still use the Phillips screws. Just use an impact hammer for removing and tightening the screws and you should be fine. The Subaru Fuji bond is also outdated so don’t use it, instead get there new pink tri-metal RTV sealant. This is about the best sealant I have ever used and use it on all other vehicle types. The only other sealant that I could say is better is the Toyota FIPG black sealant, but they don’t sell it in a caulking gun tube like Subaru does. When replacing the baffle plate I always recommend to replace the rear main seal also, it just doesn’t make since not too. Your right there already and the part is fairly inexpensive.

Subaru 2.5L SOHC Piston Access Plugs

I have been seeing these piston access plugs on the 2.5L SOHC engines leaking. I’m not sure fully why, but it’s as simple as removing it and applying sealant to the threads. The reason I’m pointing this out is because during timing belt replacement at around 105K, you may replace the cam and crank seals and overlook this area. Compared to the DOHC engines the cam and crank seals practically don’t even leak. I still replace the seals due to mileage with OEM seals, but have got burned with not re-sealing these access plugs. So, if your replacing your own timing belt or having a shop do it, let them know you want these sealed again. There are two plugs; one above the water pump and the other one is to the left of the oil pump if you’re facing the engine.

Subaru Repair Portland Oregon

If you live in the Milwaukie or Portland Oregon area give us a call or contact us for a free vehicle inspection on your Subaru. I have over 13 years experience in Subaru repair and am offering repair services at $40.00 hour labor rate. You will not find a more experienced Subaru Mechanic for that price in the Portland Metro Area or most likely anywhere near here.

This post was written by: Martin Hand

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Martin Hand

About Martin Hand

ASE Certified L1 Advanced Mastertech. Martin Hand has over 15 years experience in Asian and European Import Auto Repair. Specializing in electrical diagnosis, engine performance, AT/MT transmission repair/rebuild. Martin is also pursuing a degree in Computers Science & Information Systems starting at Portland Community College while he plans to transfer to OIT. Certified in Java application level programming, experienced with other languages such as PHP, Ruby, JavaScript and Swift. Martin has future plans of automotive diagnostic software development.

160 Comments

  • Greg says:

    I replaced the spark plug tube seals on my sons 2005 Forester 2 years ago and again recently (about 5 weeks) on the drivers side. # 2 cylinder was the one leaking most recently. I just checked the ignition wires tonite and damn if the #2 wasn’t covered in oil. How could this be after replacing the seals only 5 weeks ago? A crack in the spark plug tube itself? How can I check?

    • Martin Hand Martin Hand says:

      Subaru’s are very prone to leak there. You need to buy the gaskets from Subaru, they are the only gaskets that will actually hold up. Valve cover gaskets (2) 13294AA053 or possibly 13294AA070 and spark plug tube seals (4) 10966AA030, if your using gen1 valve cover gaskets (the ones ending in 053) then you will also need 10 bolt grommets 13271AA071. If you do not have a local Subaru dealer try using these part numbers on eBay or they have websites that sell OES Subaru parts.

  • Jack W Radzelovage says:

    hello!

    i just redid the head gaskets on my ’00 forester. it was quite a journey but i completed it up until it was time to start it again… it ran rough idle (i broke and subsequently cheesed some vacuum hoses together) but the bigger issue was that the bottom of the dipstick tube was loose and it emptied the entire oil pan in about 7 seconds… i cleaned it all up and replaced the o rings with new ones but even cranking without starting it is enough to shove more oil out the tube. its in as far as it will go, and it seems to hold just fine with no pressure on it, but as soon as theres pressure the seals immediately quit… im about to cheese this too (jb weld the darn thing shut forever) and this forum is my last resort! Help! :/

    btw, theres zero corrosion anywhere on it so rot isnt an issue

    • Martin Hand Martin Hand says:

      Should not blow oil out of the tube with dipstick removed. You have some other type of problem like excessive blow-by or some issue with the oil flow. I have left the off before and started these Subaru 2.5L engines with no problem. Idk but I would double check everything, remove oil cap then start it.

      • Jack W Radzelovage says:

        it appears that the o-rings dont reseat correctly without using enough force to potentially bend the tube. i got replacement rings and installed them, but even without being able to wiggle them in the tube the pressure from a partial crank (not even turning over) was enough to push oil out as if there were nothing blocking it at all. i doubt its blow by since it didnt do anything like that before, and i didnt mess with the pistons during the gasket replacement. could it be excessive amounts of air in a line somewhere?

        either way, thanks for the replies. im gonna try to shove the tube in regardless of if i bend it or not, and if i break it im gonna plug the hole with a wooden dowel and hope it stays for the 500 mile trip its about to make

        thanks again!

  • mike says:

    hi there i have a Subaru forester 2007 cross sport and its leaking oil on the spark plugs could this be affecting the power perfomance

  • M Bowles says:

    Have a used Subaru Impreza etc 2003.
    The smell of burning oil/rubber comes inside the car & a little bit of smoke comes out of the engine. We don’t see any oil leaking while looking at the running engine.
    Thinking it could be the piston o rings (seals), Does this sound correct to you? What else can cause this?

    • Martin Hand Martin Hand says:

      Oil or maybe cv axle grease is probably getting on the exhaust. The catalytic converters cover up oil burn from piston rings so you wouldn’t see it smoke or smell it the oil just dissapates away over time.

  • Chad Kaster says:

    I’m looking to purchase a 2010 Forester for my daughter but may have concerns about the Subaru head gasket leaking issue I’ve been hearing about. Should I be concerned? Is there a year where this concern ends? Any information would be appreciated!

    • Martin Hand Martin Hand says:

      The newer Subaru’s engines have been re-designed. They are now timing chain engines & I believe they do not have headgasket problems like the older J25. Not sure what year they changed over though.

  • Jerry Anton says:

    2015 Subaru Outback leaking oil at oilpan. Subaru says they will drop engine and fix. Give me a loaner car, Disappointed. anyone else? 30k miles, bought their service contact.
    Thanks

  • Peter hernandez says:

    Also have top of engineoil leak below intercooler will have to remove to inspect pcv area

  • Peter hernandez says:

    2006 subaru sti with 114,000 miles on it I have a cel po448 ,had a cel po442 and 456 cleared after replacing evap charcoal canister and purge solenoid valve checked electrical connections for grd continuity and 12v power where applicable found no ground continuity at purge solenoid connector unable to program pcm signal with tools i have any help greatly appreciated muchas gracias

    • Martin Hand Martin Hand says:

      There will be no ground continuity because the ground is controlled by the pcm, that is how the computer controls the solenoids (ground controlled circuit). Most all automotive electrical circuits today are ground controlled.

  • Question on a 08 Tribeca with the big 6 in it where is the most likely place for a oil leak???

  • Greg says:

    I have a 2006 Subaru Legacy. The transmission is blowing oil out the vent tube. I took it by a transmission shop to have looked at. They thought it was over filled and corrected the level. It is still losing oil from the vent tube. What do you think maybe going on ?

    • Martin Hand Martin Hand says:

      I have never seen that on a Subaru transmission before? Oil blowing out the vent hose usually means that the transmission is overfilled or it’s getting hot. So monitor how long you run before starts venting oil to give you an idea if it’s a heat related problem or not.

  • Steven E Ellis says:

    Hi
    My name is Steve, I have recently purchased a 06 legacy 2.5 n/a and would like to take you up on your offer for the free inspection.

    • Martin Hand Martin Hand says:

      Steve
      Sorry about the delayed response. Our comments responses are delayed, too busy to maintain the website regularly. Go to contact us to email me or give us a call for faster response thanks.

  • Harry Obrian says:

    Help!.. Please.
    I have an 08 Subaru Outback LLBean with the H6 3.0 motor with 103K miles on the odometer. I’ve owned it since new. It has developed an oil leak in the upper oil pan, driver’s side front. From first bush it appears that the front and rear timing covers have to be removed to get the upper pan off, is that true? And would it be beneficial to remove the motor to do all this?
    Thank you for your time and cooperation.

    • Martin Hand Martin Hand says:

      The oil leak is most likely coming from the rear timing cover and yes I would recommend to remove the engine for this repair but it can be done in the vehicle.

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