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I have a 2004 Subaru Outback that I recently purchased used for 3300 from a used dealer. I thought I had thoroughly checked things, even went to Auto Zone and had them look for any codes which they found none. I felt confident in its condition. Needed a little TLC like new battery and alternator and oil was due for a change cause it was black and bout 50 miles or so past the sticker mileage on the wind shield. Upon purchasing it I immediately got the oil changed as working 2 jobs I don’t really have alot of time. And I’m positive they did a decent job and used a detergent to clean the old sludge out before draining.
A couple days after this I was just looking the engine over while I some time, and noticed oil around the spark plug boot. And after checking the oil dipstick noticed it was above the fill mark, was dark black still, and smelled like gas which I have a bad nose usually and could have easily missed that when first checking the car. I opened the oil fill cap and while its running I get a pulse of air out, but goes away if its revved up to 2000 RPM or so and online sources say that’s normal for Subarus.
Call me a fool if you like but I wanted a Subaru expert to look this over and tell me what might be going on. So i took it to a local Subaru Dealership just for diagnostic, and got a mixed bag of answers. The service manager told me it was not bad piston rings it was a blown head gasket. and would cost 2250 to repair. Obviously I said no thank you. Upon getting the car and the papers with there leak down test results it clearly states the PSI tested and how much percentage of leak. And 3 of 4 the cylinders are described as leaking past the piston rings. So no clue if that was a premature conclusion or the service manager was pulling something on me. But glad on many fronts to not have been dumb enough to pay more than 2 / 3 the cost of the car for them to work on it. Though they did mention having Denzo spark plugs when it needs NKG’s which I will replace upon the final repair. Also in the picture at the top it said measured at 90 PSI but that got cut of in copying.
I’m gonna keep asking around and getting info before I drive it any more as I don’t want to wear out the engine with gas in the oil. Also note there is NO water in the oil as there is no milky color or consistency. just pitch black right after changing.
What could likely be the problem. Head gasket, or bad rings?
Thank you guys for any help, and God Bless!!!
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I’m no Subaru expert..
I would do a compression test
I should think a healthy engine would be around or above the 120 – 130 across the board.Have you check for excessive blow by in the crank case?
As to the leak down test, they should have told you exactly where the leak(s) were occurring.
Lets face it each cylinder has 4 choices
it will leak:
Into the crank case (worn rings, damaged cylinder borer)
Into the cooling system (bad head / block or head gasket)
Into the intake (bad valve or seat)
Into the exhaust (bad valve or seat)Subaru has notorious problems with head gaskets. The dealership probably jumped straight to that because they do so many of them. Note the picture below, the gasket on the right has failed, note the silver areas around the cylinder bores.
I agree with head gasket, you have piston ring leakage but not the amount of leakage that you’re describing.
The price they gave you is pretty average. It’s a time consuming job to do and you have to replace multiple gaskets that you take off to get down there and with it being a 04 it probably has a ton of torque to yield bolts that’ll have to be replaced.
Also piston rings would be in the same ballpark of price.
14% leakage isnt that bad. Enough for concern, and if you can tell it’s coming out from somewhere else (diff spark plug) then it probably is a bad head gasket.
And yes, its a time consuming job.
And a compression test won’t always tell you its a bad head gasket.
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ETCG just got done with a guy that had low compression in another vehicle. They said it’s supposed to be 140-180 psi’s. Yours is 90. You say you want to keep it off of the road but how would the thing drive at all with the compression being so low? Your situation is chaotic.
wouldn’t oil in plug wells point to a leaky valve cover gasket?Have you ever replaced an engine? If it were my car, I’m just a motorist, I’d either junk it or get an engine swap not even consider a new head gasket. Just replace the entire engine with a used.
[quote=”maxiitech” post=171857]ETCG just got done with a guy that had low compression in another vehicle. They said it’s supposed to be 140-180 psi’s. Yours is 90. You say you want to keep it off of the road but how would the thing drive at all with the compression being so low? Your situation is chaotic.
wouldn’t oil in plug wells point to a leaky valve cover gasket?Have you ever replaced an engine? If it were my car, I’m just a motorist, I’d either junk it or get an engine swap not even consider a new head gasket. Just replace the entire engine with a used.[/quote]
The 90 psi isn’t the reading from a compression check. That’s the air pressure applied when the leak down test was done.
Why are these Subaru’s BHG’s? Is it that the coolant is not being replaced properly? That’s some of the issues with these Japanese cars. In the Maxima the engine holds one gallon of 50/50. So even after draining the radiator you only get one gallon. I could see how someone could blow it and get the wrong mixture.
[quote=”maxiitech” post=171951]Why are these Subaru’s BHG’s? Is it that the coolant is not being replaced properly? That’s some of the issues with these Japanese cars. In the Maxima the engine holds one gallon of 50/50. So even after draining the radiator you only get one gallon. I could see how someone could blow it and get the wrong mixture.[/quote]
The constant expansion and contraction from heating and cooling cycles of the engine is what typically wears out the head gaskets. When replacing the HG’s make sure to use the multi layer gaskets they don’t seem to have this issue or they last longer due to their design only time will tell.
I would imagine the OP’s vehicle has the 2.5 with 130k – 150k miles on it. That is the mileage range that I usually see on them when I get them to fix.
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