944_S_TYPE

Hi,
Why do the "S" lifters have such a problem with clacking.I have one that just started. What is it that causes the noise? they are hydraulic right? anyone here replaced lifters in a "S" motor before? I could not find an answer while doing a forum search.
Thanks

Jay W

When I got mine it was wrecked and hadnt run in several years. It made a horrible clacking for long enough a periiod of time that I ended up pulling the valve cover to make sure the cams were ok. They were so I put some rislone in the oil to help out the oil flow. Within a couple of minutes virtually all the noise was gone, and I left it in there until I changed the oil. I havent put any more additives in there since then and it still runs quiet. The lifters have springs in them and one could have gone bad on your car.

944_S_TYPE

So they are hydraulically pressurized with a spring assist? If the spring broke would that cause them to make the clacking noise? Will it hurt the motor to run like that?

944_S_TYPE

Bump.... Anyone ever changed lifters????????

Waterguy

Just changed 4 of 8 while doing a valve job on my 951. I had two weak lifters that "clacked", especially on hot restarts, and two more that had worn through their chrome plating. Changing them looks different on an S, though; looks like you pull the cam cover, remove the cams and the sixteen cam follower ("hydraulic lifters") are sitting on top of the valves. If you can, isolate the noisy one before you pull them out. If not, set them all in a tray of clean light oil and see if you can compress them by hand (YOU HAVE TO KEEP THEM IN THEIR ORIGINAL ORDER!) Two of mine could be compressed easily with the tip of my finger, so they were replaced. The others could be compressed a tiny bit by hand. The new replacements came from the dealer presoaked in oil and could not be compressed at all by hand.

I think they have a spring and a one-way hydraulic valve in them. The valve either goes or gets clogged with gunk, allowing the spring to compress. Try the Rislone additive trick to clean the hydraulic valves before you pull it apart; those cam follower things are not cheap to replace if you are doing more than one!

944_S_TYPE

Thanks for the help. So get a tray of oil...And fill it about an inch or two? sit the hyd lifter assy. in the oil, Then just press on them to find the weak ones? I 'll Start checking the manuals.... Anyone here ever changed them On a "S"????

944_S_TYPE

Has anyone reinstalled the 2 cams in an "S" after removing them? Can it be done WITHOUT the 2 dial indicators? Maybe by marking the cams....?

944_S_TYPE

Hmmmm, Has anyone on here ever taken apart a head from a 944"S" Motor?

Jay W

I think it is a very very precise measurement with the dial indicator so even if you marked them they may be a bit off on reassembly. I have heard someone say they had the adjustment done and noticed a big difference in performance because the cams had not been measured out properly on an install. You can take your chances. Really the rislone made a heck of a difference on my car. Did yours sit for a period of time like mine did?

Porsche-O-Phile

What's the deal about not reusing them or getting the orders mixed up? Do they really wear that differently from one location to the next? I'm probably going to be changing the cam tower out to a 951 one on the turbo project car, so I'm thinking I should just get a set of eight new lifters but that's a bit expensive if I don't have to and can just re-use the ones that are in the n/a cam tower now. I'll spend the $$$ if I have to, but just what is the exact reason people say not to do it? Is it really going to screw up the cam that bad?