16V chain tensioner
09-23-2021, 12:01 AM
#1
Rennlist Member
Thread Starter
16V chain tensioner
Hey guys Im working on a 968 but since the tensioners are similar, wanted to get some other feedback
So first thing, the check valve for the oil feed (the one with the green O-ring) didnt have its spring in it f(rom the P.O.) dont know how many miles it ran like that, I didnt notice any in its running.
So where can I get a spring?
and I have read something about "pressurizing/testing" the tensioner with compressed air.... and a special tool, which I dont have. Im not sure why this is necessary? If it worked before it should work now and Id rather not wait to order the tool.
So first thing, the check valve for the oil feed (the one with the green O-ring) didnt have its spring in it f(rom the P.O.) dont know how many miles it ran like that, I didnt notice any in its running.
So where can I get a spring?
and I have read something about "pressurizing/testing" the tensioner with compressed air.... and a special tool, which I dont have. Im not sure why this is necessary? If it worked before it should work now and Id rather not wait to order the tool.
09-23-2021, 02:47 AM
#2
Rennlist Member
Hey, just wanted to tell you that the 928 never used the variocam chain tensioner from factory although someone did install them with moderate success here.
You can google 928SG for more info on this.
We got basically the same tensioner as a 944 S2 though which never had a check valve IIRC, the 968 tensioner unfortunately is model specific so you will definitely have better luck back in the 944 forums!
You can google 928SG for more info on this.
We got basically the same tensioner as a 944 S2 though which never had a check valve IIRC, the 968 tensioner unfortunately is model specific so you will definitely have better luck back in the 944 forums!
09-23-2021, 03:11 AM
#3
Former Sponsor
Hey guys Im working on a 968 but since the tensioners are similar, wanted to get some other feedback
So first thing, the check valve for the oil feed (the one with the green O-ring) didnt have its spring in it f(rom the P.O.) dont know how many miles it ran like that, I didnt notice any in its running.
So where can I get a spring?
and I have read something about "pressurizing/testing" the tensioner with compressed air.... and a special tool, which I dont have. Im not sure why this is necessary? If it worked before it should work now and Id rather not wait to order the tool.
So first thing, the check valve for the oil feed (the one with the green O-ring) didnt have its spring in it f(rom the P.O.) dont know how many miles it ran like that, I didnt notice any in its running.
So where can I get a spring?
and I have read something about "pressurizing/testing" the tensioner with compressed air.... and a special tool, which I dont have. Im not sure why this is necessary? If it worked before it should work now and Id rather not wait to order the tool.
You can get a spring from Porsche. Although interesting that it is missing, gravity should keep the check ball from letting oil return from the head.
The "air" in the tensioner was mostly used when setting cam timing. This worked fine, when the tensioners were brand new, but after the tensioner piston wore in the bore, the amount of air that leaked past was to severe to move the piston to the limit. (Even using a pressure tank of oil doesn't work, on some of the tensioners.)
The result is that a boatload of 968 engines have the cam timing incorrectly set, once someone messes with the cams, chain, or tensioner.
There's an alternative way to set the cam timing...I've written about thus other method.
Last edited by GregBBRD; 09-23-2021 at 03:13 AM.
09-23-2021, 03:41 AM
#4
Rennlist Member
Thread Starter
I know a little bit...
You can get a spring from Porsche. Although interesting that it is missing, gravity should keep the check ball from letting oil return from the head.
The "air" in the tensioner was mostly used when setting cam timing. This worked fine, when the tensioners were brand new, but after the tensioner piston wore in the bore, the amount of air that leaked past was to severe to move the piston to the limit. (Even using a pressure tank of oil doesn't work, on some of the tensioners.)
The result is that a boatload of 968 engines have the cam timing incorrectly set, once someone messes with the cams, chain, or tensioner.
There's an alternative way to set the cam timing...I've written about thus other method.
You can get a spring from Porsche. Although interesting that it is missing, gravity should keep the check ball from letting oil return from the head.
The "air" in the tensioner was mostly used when setting cam timing. This worked fine, when the tensioners were brand new, but after the tensioner piston wore in the bore, the amount of air that leaked past was to severe to move the piston to the limit. (Even using a pressure tank of oil doesn't work, on some of the tensioners.)
The result is that a boatload of 968 engines have the cam timing incorrectly set, once someone messes with the cams, chain, or tensioner.
There's an alternative way to set the cam timing...I've written about thus other method.
I locked the timing down before I took things apart.
do you have a link to the other method?