Possible head gasket

[bear2]

I have a 2006 PT C non turbo # 2 cylinder has only 35 lbs compression the others have 175 lbs. I squirted oil in the cylinder and it went up to 100 lbs
but then right back down. I'm think a blown head gasket. It dosen't lose coolent.

[NitroPT]

Originally Posted by bear2

I have a 2006 PT C non turbo # 2 cylinder has only 35 lbs compression the others have 175 lbs. I squirted oil in the cylinder and it went up to 100 lbs
but then right back down. I'm think a blown head gasket. It doesn't lose coolant.

Um... if you only have 35lbs it really does not matter you need to pull the head and investigate.
Oh and Welcome to the forum

Maybe go start a welcome to the forum thread and tell us a little about yourself?

[ptcruisersteve]

Welcome to the forum.

[Vengence]

My guess would not be a Blown Head Gasket. Possible? Yes...But, In my opinion I would check all the Valves in Cylinder #2. Some could be burnt/bent. I am also speaking of experience on this as I had the same issue....although, my compressions wasnt that low......Going to have to take the head off and everything anyways. but my opinion, I think it's a valve issue and not a Head Gasket. Also, if it is just the valves.....better to resurface the engine as well as the Head Gasket.

Side note- If all you are getting error code wise is a P0302 for a cylinder misfire, it may just be what I am assuming.....I think the Head Gasket would throw a totally different code than a cylinder misfire code. (If your getting one at all but, with what your saying, I'm sure you do)

[NitroPT]

^^^ Vacuum gauge would confirm the theory

[wb2kki]

The increase in pressure with oil would lead me to rings. But you may have other issues.
You need to do a leak down test. That will tell you where all the pressure is going.

Many vids on how to do this and how to make a makeshift tool.

Good luck!

[AnRAutotech]

Hello,
If you did proper cylinder compression checking and comparing to all other cylinders with that amount of low a compression it is easier to remove head and see where the problem is. No matter you would need to remove the head for repairs. Or if you are sure that is the rings remove complete engine and transmission for repairs.
Yes I agree that starting engine with a vacuum gauge can see if the valves are the problem.

[UnitD77]

Oil adding pressure means rings. If it drains quickly, Its bad. If it is one cylinder you might have a chipped piston on the edge. If you have a china freight bore scope that could do you some good. What color is the smoke coming out of the tail pipe, that will give you some idea as to the head gasket leak type, assuming it was a head gasket. My guess is on the rings, or piston chipping.