87' 944na hydraulic lifters?

[pnbell]

Every morning I hear "Clacka'Clacka'Clack" which then quiets but remains audible. It can be heard while driving at low speed between 2-4k revs. I have traced the noise to the rear of the Cam Tower, exhaust lifter I think.
So any advice on any of this/where to get replacement lifters?

87' 944na 175k miles; tried marvel mystery oil before last oil change. Now running 15w50.

[KevinOyler]

It is normal for worn hydraulic lifters to lose some of their oil overnght and be noisy. Sound should subside as oil pressure builds after startup. Sometimes it can take several minutes if the lifter was completely drained, like when replaced. Replacement lifters are available from the dealer for OE and in the aftermarket. Check the usual sources for both and compare.

[markwemple]

Does the noise ever go away? I saw a lifter, recently, that was replaced due to the top wearing through completely. Never had seen that before but it happens (only on 44s?). Anyway, how's your oil pressure?

[Marc A]

A failed 944 lifter will put a valve into the piston. Porsche does not make lifters anymore, they are all aftermarket, and not of the same quality as the OE version.

I had a lifter "pop" without warning. The lifter is a bucket with a hole drilled in the middle. A spring is placed in the bore followed by a piston that has a lip. The piston is pressed in place and the edge of the bore is "notched" in four places to hold the lip of the piston in the lifter.

The oil is draining out of the lifter because of two possibilities. The first is that lifter bucket has worn the journal of head in which it travels up and down and the oil is leaking past the lifter. The second is that the notches are wearing out and the oil is escaping down the lifter piston.

Either way head work/replacement is in the near future.