Seafoam to fix stuck ring?

[rrw2323]

Hi all,

Just changed both head gaskets on a 2000 Astro 4.3 W w/ 132k that I bought as a project. After completion there is a misfire on the No. 2 cylinder(PO302). I did a compression test on that cylinder and it read 85, while the other two on that head read 135. There is also a faint knock that I can't exactly pinpoint with a stethascope. (Could hear nothing through the oil pan). Possible stuck ring? I bought a can of Seafoam. I am unsure of whether to add any directly through the spark plug hole, or just through the intake. any feedback would be greatly appreciated.

[jeff's93astro]

i'm not sure about putting it directly into the cylinder. But if it was mine i'd just suck the whole can into it through a vac and let it sit 15-20 minutes then crank it. i dont know if it'll help with the compression but i did the samething to my truck and it helped with with the stuck oil rings

[astro355]

Perhaps before you try fixing it, you diagnose it first. You will need to do a leak down test on that cylinder. Where you hear the air coming from will tell you what is leaking:

If you hear the sound of air:
-from the throttle body, the intake valve is open or leaking
-from the exhaust, the exhaust valve is open or leaking
-from the dipstick for the oil, the rings are bad or aren't sealing, it is leaking internally or head gasket is faulty
-from the radiator or overflow container (which will also make bubbles), it is leaking internally or head gasket is faulty

Also forgot that it can leak externally if the seal between the head, head gasket and block is not right. You would hear air blowing and feel cold air coming from the leak. That could be caused by a cracked head, improper torquing sequence, debris, etc.

[red98tj]

A small amount of auto trans fluid in with the motor oil sometimes helps free up sticky valves or lifters. maybe a pint or so.

[Gary]

Not a big fan of the short cut repairs in a bottle.

[rev_les]

I have to agree with 355 on this one..... don't try fixing something you're not sure is the problem. Figure out WHERE the compression is going first. Also, what was the reason for changing the head gaskets at 132K? Was the misfire there before? Has coolant pooled in that cylinder and remained in there for any length of time?

[rrw2323]

Ran the Seafoam through the PCV vacuum line, turned off engine for 5 minutes, then ran til the smoke cleared. Erased my PO302 code and SES has not been on since. I agree that I should have done a definitive diagnosis, but I don't have compressed air. Threw a $6.49 hail mary and to my amazement, it worked!

[astroturf]

Glad it worked out for you. Happy motoring.

[rev_les]

i might seafoam mine this weekend just to fog the neighbors out
Glad it worked