Noisey tappets

[corkie]

Hi sorry for the many questions but im clueless on the workings of engines my tappets make quite a racket when the engine is cold when it warms up they go to sleep is this normal ?do they need replacing?is replacement a head off job?is it exspensive?it runs fine ive had them adjusted before but it didnt seem to make much difference !if left will it do much damage?ive seen some tappet cleaning additive Would this help or not?regards

[ravstar13]

Is it an m40 engine?

[corkie]

M20b25

[wullie325i]

set the clearance on the tappets that will shut them up a bit.

[Gavt]

Head stays on its just the rocker cover that comes off.
There is a guide in the wiki on this site or plenty of hits on google with videos.
The tappet addative will not solve it its for hydraulic tappets yours are mechanical.

[corkie]

Thanks are you sure their not hydroloc its a 92 325 cabbie its just i always thought they were !

[gromgsxr]

m20's are not hydraulic

[fb]

Deffo not hydralic ! i set mine on my 325i and they're extremely quiet.

[Brianmoooore]

First of all, are you sure the noise is coming from the tappets? M20 cast iron exhaust manifolds are notorious for warping and breaking their securing studs at either end. This often leads to an exhaust blow when cold, that closes up as the engine warms up and can easily be mistaken for tappet noise.
Run the engine at around 2000 RPM, and turn the key off. Exhaust blow noise should cease instantly, while tappet noise should continue as the engine slows.
If it is tappet noise, check that oil is reaching the top end of the engine correctly, especially that the small retaining plate for the two rocker shafts and held in by the rocker cover, is present and in place.
Oil is fed to the cylinder head along side one of the head bolts on the exhaust side of a M20, and passes through a drilling in one of the rocker shaft supports, into the exhaust rocker shaft itself, and from there, via other drillings, into the inlet rocker shaft,and the drip bar that lubricates the camshaft. If the locking plate is missing, the rocker shafts can rotate, and the holes in the shafts will no longer line up with the drillings, cutting off the oil.

[corkie]

Defo not exhaust got a ss manifold fitted !will check the rest thanks!

[corkie]

Set the clearence correctly on all and their still noisey

[paultv]

I know this is a bit of a numpty point, but mine were still noisy after a tweak, but then fresh 15W40 oil and filter made it quiet again, the previous owner said he'd used 10w40, which is a bit thin, no?

Probably talking out of my exhaust pipe but it made a big difference.

Paul

[gromgsxr]

the injectors are pretty noisy as well is it possibly those making the tick?

[corkie]

Just had all injectors cleaned!seems to be a bit quiter today!!