An explanation on tapping lifters ?

[Noisey]

Came across this by chance

The problem is not so much the lifter but rather design of the V6 which has very large oil drainage paths in the cylinder heads. The oil (at idle speed) simply drops back into the sump too fast- this is easy to test-if a lifter is ticking at idle simply increase the revs and it soon dissapears as the oil pump is now pushing plenty of oil into the cylinder heads - foot off and the ticking will come back at idle speed.

The heads are removed and a thread is tapped into one of the drain holes. This is then sealed with a plug which is threaded into the tapped drain hole. The 'leak down" rate of the oil is reduced which means oil stays in the lifter longer - hydraulic pressure is maintained on the valve lash adjuster (clearance is zero) and the noise is gone!

Whilst it is irritating there is no real detrimental effect on the engine.

Mind you there was also talk of drilling out the "feed" hole in the lifter to allow more oil through or replacing them with models from other vehichles that are produced with a larger feeder holes.

[DougH]

It makes sense, but not complete sense to me.

The oil goes straight into the lifters under pressure. The oil doesn't leave the cylinder head under pressure, it just drips back down to the pan as far as I know.

Plugging one of the drain holes will result in more oil in the heads, but I don't see it helping the lifters keep pressure at all. The only way it could is if the heads were 100% filled with oil and that doesn't come close to happening.

[.:Dave:.]

Just turn the radio up, does the trick for me