Tappets or camshaft?

[walkie]

Hello all, the engine makes a knocking noise when cold, for about 1-2 mins, just like when 1 or 2 tappets are on the way out. The engine has done 60k and it's a 500. Could it be just the tappets or it's time to change the camshaft? The noise completely disappears when the engine is warm.

thanks in advance.

[GreenV8S]

It's academic really, because you will need to change the cam and tappets as a set (plus the drive gears and chain, at that age) if you change anything. Check that it isn't something else such as an exhaust manifold gasket leak or cracked exhaust headers though - these can come and go with temperature and make a very sharp tapping noise that sounds mechanical.

[rev-erend]

What he said

[coetzeeh]

A numpty's 2p here - my Griff 500 also makes a knocking noise for a minute or two, especially when cold - I think it is a bit of piston slap which 500's apparently suffer from. Could it be this?

[walkie]

Thanks for the ideas, I guess it's time change the cam and the tappets, it's definitely not the manifolds. I found many aftermarket camshafts for rover v8s, stating they're all fine for tvrs too. I wonder if it's the truth as I think the tvr engines have modified camshafts?

[thegman]

walkie said:

Thanks for the ideas, I guess it's time change the cam and the tappets, it's definitely not the manifolds. I found many aftermarket camshafts for rover v8s, stating they're all fine for tvrs too. I wonder if it's the truth as I think the tvr engines have modified camshafts?

try v8 developments.

[spend]

Why not just try a short-shift of diesel oil or something to see if it is just a lazy gummed up lifter which might clean out?

Dave

[steve-V8s]

My Griff sounded just as if one of the lifters was failing to prime when started from cold, after 90 secs or so it faded and then disappeared. It actually turned out to be the belt tensioner bearing so it may be worth popping the belt off and seeing if you still have the noise. Unlikely but the test is quick and costs nothing.