986 Cam Chain tensioners

[tomk]

Hi, I have an easy question for the experts on this forum. Are the cam chain tensioners pressure fed? Similar to the aircooled 911's in concept. While the latter had an external line there is nothing similar on the 986 and was wondering if the tensioners are fed pressurized oil from an internal source?

I am asking because I have the rattle on startup, and I replaced the tensioners, went from 10-30 to 10-40 oil and there is essentially no difference. I was thinking it might be lifters but the noise sounds very much like a chain rattle rather than what i associate with lifters not pumping up.

As soon as the oil lite goes out the noise stops. It doesnt do it everytime but the longer i let it sit between starts the more noticable it is. Car runs great and I love it

This is a great forum, very experienced contributors
thanks in advance

[JFP in PA]

The tensioners are pressure fed by internal oil passages.

[tomk]

Thanks JFP. I own a volvo whose year and model has a very similar behavior which is well documented on the respective forum. The apparant fix is to replace the o-ring on the oil pickup connection to the oil pump. The o-ring deteriorates and lets air in causing the pump to lose suction for a brief moment on startup. Has anyone ever heard of replacing this same o-ring on the 986 engine. I'm not even sure it uses an o-ring, but am just throwing it out there?

[JFP in PA]

Originally Posted by tomk

Thanks JFP. I own a volvo whose year and model has a very similar behavior which is well documented on the respective forum. The apparant fix is to replace the o-ring on the oil pickup connection to the oil pump. The o-ring deteriorates and lets air in causing the pump to lose suction for a brief moment on startup. Has anyone ever heard of replacing this same o-ring on the 986 engine. I'm not even sure it uses an o-ring, but am just throwing it out there?

There is no O-ring on the oil pickup in the M96 engine. The problems with the tensioners in these engines is related to wear, varnish build up in the tensioners, and oil with poor film qualities .

[tomk]

once again thanks for the info, there goes that theory. Since I have replaced the tensioners and use Mobil-1 (which I assume has adequate film quality) are there any other suggestions on how to eliminate the rattle, or should I just turn up the radio a bit more?
thanks again

[JFP in PA]

Mobil 1 has mediocre film strength compared to some other oils, do a search on the subject of oils, you will learn a lot.