Piston broke ?

[freqmikey]

The debate is raging ... is it the little end or is it the piston ? :)

Symptoms are : dull knocking at tickover, dissapears on revving and louder when engine warm - The sound is definately from the back of the block , driver side.. It's a 94 3.9 v8 with about 70k on the clock.
A trusted mechanic has said it's definately the piston not the little ends so ???? I dont quite understand how/what/why on this one... Any ideas ?? Do the pistons break up around the little ends ?? -
It was being used as a chelsea tractor and looks as though it was seriously neglected in terms of oil changes, everything in the rockerbox was full of sludge and a couple of the cam followers were also shot ...
Grateful for any advice on this one.. :rolleyes:

[TEMPL4R]

Little end is usually a rattling when you hold the revs up a bit and no load. Does tend to disappear under load.

Piston slap is when the piston trys to twist and hits the side of the bore, that tends to disappear when you put a load on the engine.

Big end tends to get loader under load.

Main gearings rumble.

The rear pistons can erode to the rings if they get water coming in from the water port, that is where it passes from the block to the heads on a V8.

Chris

[freqmikey]

Cheers Chris...I'll go along with piston slap then I think, and the inevitable take it out and have a look :rolleyes: - seems quite low mileage to have done a piston to death which was why we were avoiding taking it out if poss and looking for other causes but ... ho hum :)