Right ive got a loud loud tapping. I cant really pinpoint it. The sound is loudest at the inlet manifold of all places
Ive had the head off again(for other reasons) and built a brand new head up. This solved some other(non linked) problems but the tapping is still there. I didnt change the lifters. If i use the good old screwdriver method(as i dont have a stethascope) theres no noticeable noise by the sump and theres not that much difference up on the rocker either.
Just wondered if theres any easy way to tell if it is the big ends. Oh and it doesnt tap constantly. It will do it at idle and if i quickly rev in neutral. Or it will do it constantly under load but not if i maintain the same speed

Cheers, Harry

 

Why didn't youy change the lifters?

The do completely collapse you know.

If it was a big end, it would go quiet while you reved it and then com back as the revs stabilised.

 

Because i didnt have any spare. Waiting for some to turn up thanks to royal mail.
So basically it shouldn't be tapping when pulling away etc whilst driving if its the big ends?

 

As above


Dave

 

if it was the lifters it would tap contanly if one had collapsed, it sounds like big ends to me mine went on friday. when the big end bearings go the knocking is caused from 'piston slap' so there would be no more noise at the sump than there would be at the head. does the knoking start when you rev it and when the revs stabalise does it go away then come back when you decease the revs?

 

also how long has it been knocking for

 

Been knocking for about 2 weeks. Happens at idle(really sounds like a tappet at this point) then it will tap from 2000-4000 in neutral. But will knock constant under load but never at constant speed

 

after doing a constant speed and then let off will the knoking come back. has it got worse over the 2 weeks?

 

Same over the 2 weeks. If i do a constant speed then just let off of throttle, then no it doesnt come back till i accelerate again

 

mine went from bad to worse to almost undrivable in about 50 mile. but i would certainly check it out cus if it is your bigends then it will be very costly or totally ruin your engine if left with a piston going through your block it maybe just a case of replacing the shims which is not as hard as people may think.

 

shims? Same thing as shells yer?

 

yeah me getting confused still suffering with a hang over

 

big ends or piston slap

 

the reason for piston slap is due to big end bearing being very worn

 

Sounds like a bottom end problem to me, time to take the sump off.

 

hello my fully rebuilt engine is dfoing the exact same thing ever since i started it. new mains and big ends fitted so dont think its then cause its done it since its first mile of driving. sounds like a loud tapping noise from back of head near inlet manifold. when i pull of spark plug lead for no3 cylinder it stops! Going for a compression test as thought it may be a valve? Mine pops and backfires when going downhill in gear and not touching accelerator does yours?

 

Yer but mines always popped. Its not backfiring tho. And it doesnt stop if i remove any of the plugs
Im getting the sump off today to have a look anyway