knocking sound under acceleration when pulling

[mclaren]

hi

i hav a knocking sound under acceleration when pulling my boat ,sounds 2 be coming from around dashboard "while i'm in the paj".when i idle the paj and rev the engine i hear no sound ,aswell as when i drive it without a boat.

any ideas?

[mattza13]

diesel or petrol??

is it a knock, or i higher pitch 'tick'.
if its more of a ticking sound it could be ur stem seals are dry or somehting of teh like. had the same problem in my car, turbo diesel.
the problem fixed itself with a good quality oil run through it.

[mclaren]

petrol,but will try new oil

[mclaren]

i hav 1989 3.0l v6

[smccask]

your engine is probably pinging (ie pre-ignition) it could be caused by:
to far advanced ignition timing, carbon deposits in combustion chamber, car overheating (perhaps locally), lean a/f ratio in one cylinder, or bad fuel.

[mclaren]

i did the test in the paj book with each lead at the spark plugs and here no difference the sound is still there. can't hardly here it if at the engine,bot can here it inside the cabin. the noise is there sometimes and other times not.it was there this morning after a ride for petrol and if i rev it when standing still aswell