Gasket or piston ring?

[Stee111e]

Cylinder two had really low compression, coolant was quite dark with possible oil contamination. Took the head off to investigate.

Is this ring part of a piston ring or part of the gasket that sealed around the cylinder?

[E-bmw]

If that is part of a ring you will get your answer if you turn the crank to lower the piston, because there will be SIGNIFICANT damage to the bores.

First thought was ring but if it were a ring it would have been bent to feck, you need to be certain though so have a look.

BTW is there a similar sized bit of the fire ring missing from the gasket?

[rigga]

Piston ring wouldn't get out if the bore in that condition, its part of the gasket.

[Stee111e]

Thanks, that makes sense that it's the gasket. The cylinders seem in good condition with no scoring.

I'll give everything a clean replace the gasket and hope that was the problem and not a ring.

Any way I can tell if a ring has gone with out taking the piston out?

Cheers

[rigga]

If the engine was complete and the head not removed you could do a leak down test, basicly piston a tdc., air under slight pressure through spark plug or injector hole via adaptor, any hissing noise ig pressure drop through dip stick then rings or bore worn., as said if the bore looks OK when piston lowered, then likely the rings are OK


Edited for spelling

Edited by rigga on Saturday 26th May 11:38

[paintman]

Obvious question, you have checked the old gasket to see what it's missing & if the bit you have fits?

I'd agree with E-bmw & others as I can't see such a large section of a ring surviving OR being able to get on top of the piston without a substantial chunk missing from the top of the piston.