tapping noise from head

[adam g]

I have recently put my engine back together after fitting a new turbo. I started it today and heard a tapping noise that sounds like its coming from the top of the head on the inlet manifold side (not the putting noiuse of a cracked EM I dont think. If I take the oil cap off and listen it sounds louder and gets faster with revs.

Any thoughts on what it could be, I dont think it was there before but I cant be sure. The last turbo failed rather badly with a snapped shaft and compressor wheel trying to borrow its way out of the housing. I found a bit of debris in the intercooler but nothin in the oil so hoping no metal got as far as the engine,. The piston crowns didnt look damaged from what I could see through the spark plug hole.

A compression check gave 12 bar on cylinders 2-5 and about 10.5 on no.1.
Is this within acceptable limits?

I dont want to risk something else breaking and going through my new GT3071R.

[UrS4boy]

Probably just a cam follower (some people call them lifters but the actually are pushers between the cam and the top of the valve) that has leaked down. Give it some time to see if it pumps (fills) back up and the sound goes away. Don't hammer the throttle until the issue is resolved.

Item 8

[Lloyd]

Sounds silly but pour some water on the belts and see if it goes away.
If it does, happy days forget about it

[s2_wot]

If you've had the cams out I'd pull the cam cover and check the torque on the cam caps, a loose one will be very noisey. btdt

[UrS4boy]

If you've had the cams out I'd pull the cam cover and check the torque on the cam caps, a loose one will be very noisey. btdt

Yikes!! 11 lb-ft (15 Nm)

[adam g]

Sounds silly but pour some water on the belts and see if it goes away.
If it does, happy days forget about it

Sounds like quattro voodoo but what harm can it do. Will give it a whirl , (hot or cold)?

[adam g]

Haven't touched cams. Ta

[SteveH]

Sounds very much like a cam follower as mentioned above. They normally stop after a while once the oil is up to temp, however if it persists you'll need to replace or strip and clean the offending follower.

[pixsaudisex2]

I had a similar thing put new chain new blooming loads of stuff and it turned out to be the belts making the noise or a loose bolt on the alternator....

Seriously thought it was the tappets for ages...

[Cymru1]

Sounds like quattro voodoo but what harm can it do. Will give it a whirl , (hot or cold)?

Cold water is best.

Can't recall but was the water trick used for loose belts or something?

[Wrath]

Pushers as we call them in Sweden get stuck after 15 years of use a good exercise when building up the head is very useful. The way I did it in my old 200sx (had a lot of ticking noise) was in a vise with a m8 nut. Just make sure you have aluminum brackets in the vise so you don´t trash your pushers. Then just compress the pusher towards the nut with some cleaning lube and release, repeat until you can push them with you fingers. Use brake cleaner and compressed air until they are clean... also used Omega lubrication 636 (probably the best lubrication I ever used, like the WD-40 but loosen everything thats stuck) Took me 2-3 hours to do all the pushers and when all was reesembled everything was quite.