7 replies to this topic

[nightroamer]

How can i tell if i have a broken piston ring?

have a knocking sound from bottom end most noticable at idle and smoke!!??

[nomininolife]

It could be the head gasket that has blown.

[Dan]

You can't hear a cracked ring. Broken rings usually give huge (huge) plumes of thick white smoke under heavy load. You can do a leakdown test or sometimes a compression test will reveal a broken ring but not always. The only real way to be sure is to have the head off.

Knocking from the bottom end, loudest at idle? Could be your oil pump is on it's way out or a slightly worn big end that improves with increased oil pressure. Generally speaking loud knocking noises aren't good and need fixing.

[nightroamer]

dad just had a listen, thinks its one of the big ends. there new but could have an oil flow prob or summit. although pressures good, only done 100 miles lol

[Dan]

If you've got a knocking from newly fitted big ends then get the engine out quick and find out why before real damage occurs. Was this a complete re-build? Were the oilways properly cleaned out in the block and crank? Were the bearings plasti-gauged? Are the caps on the right rods and the right way round?

[nightroamer]

bottom end was done by a local guy but i think so, i could see he had marked the caps etc. im gonna take it out asap, prob is back at uni tues, think itll be lifts for a while....... start again i think

[Dan]

In that case, don't open it up yourself. Take it straight back to whoever did the work, preferably in the car so he can hear it.

[nightroamer]

will do dont u worry!! cheers dan