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.

139 Comments

  • 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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