Engine Knock

[jimmyV8]

I have an occasional and sometimes loud knock that comes from the engine when it is warm. It isnt a constant sound and sometimes are louder than others, it can be felt through the whole car not just heard. The sound can be heard when the car comes back to an idle but after a peroid of time will totally disappear. Generally car is running well with no other symptoms apart from this knock. I am quite concerned that this could be something serious?! Could it be a sticking tappet or rod? Any help or advice would be much appreciated. Thanks in advance.

[WOO5IE]

Hi

Does the knock speed up and down with engine revs,
is the oil pressure Ok.
Have you checked that nothing is loose in engine bay.
Is it internal or external to the engine.
How intermittent is it every dive every 20 secs or so ?

So many questions and so many possibilities.

Trev

[jimmyV8]

I realise that it is quite vague. It doesnt appear to speed up and down with revs and is totally intermitant. Definately an internal sound that only can be heard when car is returning to idle, not that im saying its not happening at higher revs but cant be heard easily. Engine still pulls hard and well. Almost feels like detonation but doesnt happen under acceleration and can be violent knock.

[steve-V8s]

Stick a short length ( about 3 foot) of garden hose in the boot, When you have the noise put one end in the ear and offer the other end up around the engine to track down the source.