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Subaru cylinder problem

Ok I am new to this but I have a serious car problem. The day before my road trip from VA to ME I had the oil changed in my 2006/120,000 mile subaru Forester. Soon after getting on the road I noticed a burning smell and smoke coming from my engine. I called my mechanic and he said it was dripped oil burning off. about an hour later we noticed oil dripping from the engine and when we checked the oil we noticed it was overfilled. We then took it to a nearby mechanic who said they thought the oil tank had been overfilled and may have blown out the camshaft seal and that was the cause of the drip and oil burning. They said it was a repair that would take some time, but when asked the mechanic also said we would do no harm and it wouldn’t be dangerous to drive so long as we kept the oil levels up. An hour on the road and the car started to vibrate and lose power. So we took it to yet another mechanic (same group as the prior two) the next morning and they concurred that it was likely the camshaft seal but would take several days to repair, and diagnose and repair the cause of the vibration. after a week I was told that the repair to the camshaft had indeed fixed the oil leak but that with further examination it was discovered that the pressure in one of the cylinders was 20 lbs not the 100lb it’s supposed to be.
So my question is - could there be a link between the overfilled oil tank, the damaged camshaft seal and the cylinder.
Thanks.

Both of those numbers you cite (20 and 100) are wrong. Ideally, compression numbers on a good engine should be in the 180-190 PSI range.

With a cylinder at 20 PSI a wet test should have been performed to determine whether the problem is related to the piston/rings or a cylinder head valve problem.
If the other cylinders are at 100ish, or even a bit more, then the entire engine has serious issues.
If a wet test causes that number to take a significant jump up from 20 then odds are there is a piston/ring problem. If the number remains the same and only goes up slightly then odds are it’s related to a valve in the cylinder head.

There’s a number of things in your post that almost point to mass incompetence to coin a phrase. You called your mechanic on the phone and he dismissed this as oil burning off, being told that 100 PSI is good, and the lingering question of whether or not the timing belt was replaced along with the cam seal. If not, mistake.

Could overfilling blow out a cam seal? Yes, it’s possible. Could overfilling damage pistons and rings? Yes, that’s also possible.
It’s also possible that an engine attempting to hydrolock (oil forced into the combustion chamber) that cylinder head damage could be done but this is less likely.

Hope some of that helps anyway. :slight_smile: