Dana Anderson

My car makes a 'rattle' infrequently at startup. Goes away after about a block of driving. If tensioners are the problem, could you provide details on how long it took to do the removal and cleaning?

BaysideC4

Looks like I have a project for Memorial Day weekend - Any advice on this topic would be appreciated.

RallyDogRacing

Hmm, I occasionally get the dreaded noise - and was for a long time convinced it was an exhaust heat shield. But when I began thinking it sounded more like the "dragging an anchor chain from a metal trash can" sound - I've been making a point to have the door open and head outside the cabin on startup. That seems to intimidate the car enought to not make the noise anymore...

I guess that means I need to clean tensioners...

BaysideC4

Can the tensioners simply be pulled out, cleaned and reinserted? Are there any tips or tricks to doing this successfully? I know that letting the chain go slack in the older 911’s can cause serious problems.

How would one clean them anyway?

Wachuko

Sounds like someone should take the task of documenting, take photos and create a diy on this one... any takers?

JasonAndreas

There is really not much to this, just don't put them in backwards or it gets really loud. Basically you drain the oil and undo the two M6 locking nuts (999-084-094-02). I don't think you need to remove the heat exchanger crossover, I don't remember what I did the 2nd time so check if you can use a wobbly socket before you drain the oil.
The tensioner is under spring pressure so it will want to shoot out once you remove the cover. In my case the cover was filled with sludge so I used odorless mineral spirits to clean it. The tensioner is basically just a hollow cylinder with a hat surrounded by a spring. There is a small opening (oil feed bores) at the bottom of the tensioner and that is where you want to start cleaning (sorry I didn't take photos). The cover uses an aluminum crush gasket (964-105-177-03) that you should not reuse. There are also two aluminum 6.4mm x 14 x3 crush washers under the locking nuts that should be replaced (999-025-193-30).

I didn't bother with the upper left side tensioner as I was mainly just fixing leaks.

RallyDogRacing

thanks for the information. you wouldn't happen to have the torque spec on the nuts would you?

JasonAndreas

I'm sorry I don't have the torque specs for those two nuts.

axl911

This is what I got from teh manual.

Bearing bridge/chain housing: M6 nut 9.7Nm or 7ft-lb

dfinnegan

Then my guess is they don't exist!

bwoodry

According to my mechanic, the tensioners have a small o-ring or seal internally that degardes over time. This will allow oil to leak out overnight and then you get the sound upon start up. My new Tensioners took care of this sound. If I had time I would have done this myself. the left side is easily accessable and the right side requires removal of some of the exhaust system to access.
Bw

Heirsh

If its just a 50 cent seal, why are we all replacing the whole darn tensioner?

I really need to get ahold of someone's used tensioners...

ddubois

I had the chain slap noise at startup so decided to remove the tensioners and clean them (BTW, you do not have to remove the Hx crossover or any exhaust parts, it's a little tight to remove the one nut but easily done). The lower one on the right side had a 'locked' plunger that worked loose with cleaning.

Bottom line is that it did not solve the problem so I suspect the seal in the tensioner is leaking.

So is it possible to replace just the seal in the tensioners?

BaysideC4

I replaced both tensioners and that solved my problem. It was well worth it IMO -

ddubois

BaysideC4,
So before I plunk down $400 on new tensioners, I'd like to compare notes...

When the car sits overnight I get the rattling sound for about 1 second at start up, then after that everything runs great. If I let the car idle for a couple minutes (no noise), not get up to normal operating temp, turn it off and restart, I still get the noise for 1 second during startup.
Now if I drive the car around the block, get it up to normal operating temp, shut it off and restart, I don't get the noise.

Keep in mind I just cleaned the tensioners last week. The fact that one of them was 'locked' and came loose after cleaning tells me the seals were frozen and possibly no longer providing an adequate seal.

So does this sound like your symptoms before you replaced the tensionsers??

Thanks,