malbaby

On my early 944 there is lifter noise when the engine is first stsrted....Once the engine warms up, the lifter noise disappears. I replaced the old oil with new 20w-50 but that did not make any difference....Any suggestions other than replacing the lifters with new ones....Thanks.

944CS

try a lighter oil like a 10w-40, make sure the oil is topped up at all times, and if you are parking on an incline, park so the engine is on lower ground than the rear

dede944

Hi !
I changed from mobil 1 synthetic 15W50 to 5W50
and it helped a lot...
Was making noise on start-up for 2 sec. when cold.

Bardahl make a product for noisy lifter too..

xsboost90

there is a check valve between the cambox and the head- pressed in on your car- that sometimes will become less operable and bleed oil back out of the top end when not running. I would stay where you are at w/ the oil, if the lifters pump up then they are still good.

Porsche-O-Phile

If it's real bad, pull the cam tower, take the lifters out and soak them in ATF for a couple days, then reassemble.

xsboost90

could be like Ghost's car and not have the check valve at all! someone machined the head, took it out and didnt replace it. ONly like $10 for the parts but took a few weeks from germany to get them.

malbaby

Thanks for that.......also, when the engine is quite hot the oil light comes on at idle ...is there any connection with the lifter noise when cold.

Catfood

old porsches that havent had mobil 1 in them there entire life make those noises, my rebuilt 944 with mobil one since the rebuild sings a little, and my dads 928 does too. If I ever get time i may work on it.

tjbreen

I had the noise in mine when I didn't start it for a couple of weeks. I had the head rebuilt about two years ago and noticed one out of eight of the lifters could be easily compressed by hand. I replaced it and now have no noise at all no matter how long the car sits. Pulling the cam tower and testing the lifters to find the bad one will solve the problem.
While the head was out I also had it rebuilt at a very experienced shop. The machinist gave me the check valve ball, spring, and retainer separately as the spring gets crushed when the ball is pounded out so the head can be machined. I simply bought a new spring for about $5 from the dealer and replaced the pieces in the appropriate hole in the head. This ball valve mechanism seems to regulate how much oil pressure is kept in the head because the pressure compresses the spring and oil bleeds through. There must be another mechanism (like the back flow preventer on the oil filter) that keeps the pressure up in the head when the engine isn't running.

KuHL 951

My impression is the check valve you are talking about helps to keep oil in the cam cover/lifter area after shutdown...I'm not aware of any actual pressure regulation function in that valve. After all a check valve is designed to prevent backflow.

xsboost90

if you saw it you would realize that it drops pressure down to keep from blowing seals out of the top end- from the looks of it- but also has the check ball to keep the oil in the top from running back down. Now the way its designed, i cant see if failiing very easily but you never know. Most likely if its real cold you WOULD have to go to a thinner oil to let the oil get where its going alittle faster and keep the lifters from ticking so yes maybe thinner oil is a good idea.

tomrc

Interesting, I just had the head rebuilt on my car and didn't notice a check valve before or after the rebuild. I don't have lifter noise but I do need to wait <1 minute to build pressure after the car sits for awhile. Also I blew out a seal (I think the cam cover gasket) shortly after reassembly. Any place I can get a picture of the check valve and where it goes?

Thanks,

ibkevin

Because the NA is never driven, the lifters madea hella noise on starts, one qt of crankcase cleaner added and idled for 5 min prior to the oil/filter change and presto! She purrs like she used to.

chrly924s

would Marvel Mystery Oil be OK to reduce this?

crooster

I have heard that adding 1/2 liter of ATF to the oil (first drain 1/2 liter of oil!) and running like that for say 500 miles can free up a stuck lifter. I tried this with my car but it didn't help. The cam cover is coming off soon and I have some new lifters to swap in when I identify the bad one.