Also to add i do have reground cams which some have mentioned are prone to tapping, but they never did this when i first got them so i have dismissed that possibility

Don't you have reprofiled cams?

Apologies - scan reading, can give this my full attention as I actually have work to do at work :)

Don't you have reprofiled cams?

reground, but as i said they never tapped before now

Do they surface treat them after they've been ground?

Do they surface treat them after they've been ground?

doubt it, the surface hardening process is done via running the cam in properly, if that isn't done then you can loose the lobe nose!

Re-profiled cams might cause tapping as the lobe ramp is reduced, meaning the accelleration of lift is increased causing the lobes to smack the tappets instead of gradually push them...

I was thinking they may have worn down like

Could have if its not been run in after the re-profiling!

Oil pressures seem ok. Do polo tappets have shims? They might need to be measured with feeler blades and changed so they are in spec. I know that was the case with my 8v mk1 golf engine.

Temps with a thermostatic cooler and turbo is around 180f when warm, doesn't get any hotter and doesn't tap.

Hyd ones don't, but whether the adapt to the new cam lobes being smaller I don't know

Hyd ones don't, but whether the adapt to the new cam lobes being smaller I don't know

They never made a noise before now though so ime sure that can be totaly ruled out?!

so ime at a dead end, i have asked every knowledgeable car person i know and nobody has a clue, all i can come up with is when i last refitted the head i put a smear of sealant on the front L/H corner to stop potential oil leaks as recommended, and some of the sealant has maybe found its way into the oilway?

but this entails removing the head yet again...!

You don't use sealant with a gasket, you don't need to especially with the metal ones (the compound ones degrade, causing the problem there), and doing so can cause destruction of both the head and the cams if it does get in an oilway - i've seen a cam melted in a head because of this, cam melted as much as the ally did, they were utterly fused. Also found silicone sealant in said oilway, had travelled to the cam bearing, got stuck against the cam, plugging it there and causing the bearing to run dry and overheat.

If you can avoid this by taking the head off and clearing all the oilways, it'll be worth it. Could it be low oil pressure before the head though..? Do you know your pressure alarm works?

Do you know if the cam in receiving sufficient oil?

You don't use sealant with a gasket, you don't need to especially with the metal ones (the compound ones degrade, causing the problem there), and doing so can cause destruction of both the head and the cams if it does get in an oilway - i've seen a cam melted in a head because of this, cam melted as much as the ally did, they were utterly fused. Also found silicone sealant in said oilway, had travelled to the cam bearing, got stuck against the cam, plugging it there and causing the bearing to run dry and overheat.

If you can avoid this by taking the head off and clearing all the oilways, it'll be worth it. Could it be low oil pressure before the head though..? Do you know your pressure alarm works?

i think i may have to tbh, so i best buy yet another set of headbolts...

the pressure sensors read from the same place as the pressure gauge and that reads normal(ish)

Edited 19 August, 201214 yr by dubownerbilco

I doubt that's your problem, unless you put loads of sealant on, a small smear would be ok.

Mine only seems to hold about 55 psi on a good run but doesn't tap.

Are you SURE the cams are ok

I doubt that's your problem, unless you put loads of sealant on, a small smear would be ok.

Mine only seems to hold about 55 psi on a good run but doesn't tap.

Are you SURE the cams are ok

The cams were never a problem before! I dont see how after a piston ring and block change which didnt include the cams in the slightest would have changed anything cam related?!?

Edited 20 August, 201214 yr by dubownerbilco

Shitty oil pump mebbe?

He's changed the pump.

As max said they get work hardened.

I'd try changing tappets tbh.

Just because they appear ok it doesn't mean they are

Edited 20 August, 201214 yr by harris.racing

Ah my bad.

Yeah check tappets thoroughly man

He's changed the pump.

As max said they get work hardened.

I'd try changing tappets tbh.

Just because they appear ok it doesn't mean they are

from the vw the tappets are insanely expensive and everyone else seriously struggles to get them, i got one form gsf ages ago and it was one of about 12 they had left in existence!

Oh right, gonna say I got a set of 8v ones off the shelf

Oh right, gonna say I got a set of 8v ones off the shelf

i dont know what it is with the afh, but parts always seem to be abit of an effort to get

Whats the actual spec on the cams? If they're pretty lairy, they're gonna be noisy!

Whats the actual spec on the cams? If they're pretty lairy, they're gonna be noisy!

Ahhhh ime sick of saying this!

The cams were never a problem before, they have been in for over a year now and i never heard a peep from them!

But they may have worn it what i'm saying, as you haven't said you ran them in!