About a month ago, I noticed that my oil was much lower than it should have been, so I took my 96 Legacy Outback (2.5L automatic with 155,000) in to the local mechanic and also asked them to give it a tune-up. They said that the valve seals needed to be replaced and gave me an estimate of around $400.
Then, due to a series of events, they were unable to follow through with any repairs, so I took it to a different mechanic who works on lots of Japanese cars, particularly subarus, and they said that in addition to the valve seals, the head gaskets were leaking oil into the coolant. They gave me an estimate of around $2000.
I decided I wanted another opinion, since my car is only worth around $2000. The last mechanic I took it to said it was leaking oil around the timing belt, water pump, and valve seals. I had told them that I was told it was the head gasket, and I had read that it was a common problem for this model subaru, but they were insistent that it was misdiagnosed. Their estimate: $1500
Ah! Is what I thought. Why can’t I get the same answer twice? Does anyone have an opinion on my experience? I know I haven’t provided a ton of detail, and it is possible that I have slightly misquoted a mechanic at some point as I am not too car literate, but this is really frustrating. I love my car and want to fix it, but if I’m gonna spend over a grand, I want to make sure I am fixing what’s broken. thanks in advance!
The car is now 13 years old, has a 155k miles, and the oil consumption could be caused by any of those things mentioned to you including one more; and that one more is piston rings.
There is no test to determine if valve seals are faulty. It’s strictly a guess.
Leaking cam seals, front crankshaft seal leaks are detectable so that’s possible.
Head gaskets can cause oil loss or coolant diuted oil and the reverse; oil diluted coolant. A cooling system pressure test could be performed to determine if the head gaskets are leaking.
If coolant is diluting the engine oil (the oil may appear to have a sour milk consistency) then the engine’s days are numbered and a complete rebuild is needed.
A piston ring problem can often be detected with a compression and/or leakdown test.
A ring prohlem also means a complete engine overhaul.
If by “much lower” you mean the engine oil was VERY low, as in 3.5-4 quarts down, then this can also damage crank bearings, etc. Back to the engine overhaul scenario.
Hope some of that helps.