968 problem...

I have a 92 968 that is running rough at the idle. It seems the oil pressure dips in correspondance with rough idle and a "noise" in the valve cover. I am about to change the cam chain adjuster. I have changed the oil pressure relief valve but it did not fix it....

Any experience or ideas?

Like it's running on 3 cylinders?
Check your ignition wires. When it's dark, pop the hood and look for blue sparks anywhere around the wires.
Pull the connectors and cap and look for any corrosion there. Clean as necessary.
Motor mounts? I've heard about rough idle/vibration at idle w/ bad/worn motor mounts.

What's the idle RPM and your oil pressure readings?
Possibly vacuum leaks?

Thank you for the response. The oil pressure seems to dip to 2.5-3 bars and then the idle goes between 200 plus or minus the normal operating idle. It seems to go away when you use the gas, of course but there is a noise coming from below the valve cover where the cam chain tensioner is. It also makes a bit of a whine for a second as you hit the gas... I did puld the valve cover and the tensioner guides were a little worn but nothing crazy. Have you ever heard of the CCT losing oil??

I consulted and after market shop and they said this was an issue with the ealry models but they amy have been agreeing for the hell of it...

The part is close to $1000 so I want to be sure but the mechanic seems pretty convinced this is it... I am not so sold...

I'm not sold either. You still have plenty of oil pressure at idle so I jst don't see the CCT being the problem, unless it's jammed! If it were jammed the variocam wouldn't be able advance-retard the timing.

Now, that's my $.02. Please ask around though, I haven't worked on a 968 in over a year.

the vario cam needs 3 things to work. 1) oil pressure. 2) working solenoid (solenoid allows oil pressure to pass through the vario cam changing the timing. located on top of vario cam). 3) cams are timed properly.