3.2 timing chain noise (UPDATE AND PICS)
 

I have done a search on the board, but my question found no answer...I can hear a chain rattle on the right side of the engine...but only when the engine is warm and at idle (800 RPM), like after an hour drive. No noise at higher RPM and oil press is good. The ramp or the tensioner or the chain stretch ???:confused:

I would remove the right side timing chain cover and take a look.
Could be a worn out timing chain. Less likely would be a weak or bad tensioner.
A timing chain flopping around will beat up the ramps.
An original 20 year old timing chain deserves to be replaced.
Both sides.
Not over an hour to look at both sides. You'll need gaskets.

And can I do it with the engine in situ...?

Yes you can. I just did it this past week. I think you'll also need new brass washers for the two oil lines that drop into the back of the cover. I replaced the O rings as well, but it may not be necessary, just one of those .50 cent things that is a 'while you're in there thing'. You will need to remove the muffler, heat excahge pipe that feeds the fan on the motor and the rear engine tin. I was able to loosen the engine mounts a bit to get the tin out (lowers the engine a bit). It is not difficult but will take you a few of hours.

Tony...I saw in Benthley manual that the replacement chain is a split one with a master link...do you used that one...and did you follow the benthley manual...I ordered the 101 project book from Wayne...I wait for it...

Before you dive into the engine...
What kind of idle oil pressure do you have? What viscosity of oil are you using?

The Carrera chain dampers are oil pressure fed. The fact that it only does something when the oil is completely warm and oil pressure is at its lowest would lead me to believe that it may be bleeding a little fast and wants more oil.

If this is the case I would put in the later cam oiling restrictors that Porsche has superseded the earlier ones with. It is very unobtrusive and will get you at least 1.5 bar at idle.

If this doesn't seem to fit the problem then go after the damper. It isn't something that you want to wait on!

Oh, if you do the cam oil restrictors, you will need 6 washers. one for each side of the restrictors and one under the head of each bolt to seal the banjo fitting.

I don't know. I only did the tensioner cover gaskets, cam oil lines and oil lines that feed the tensioners. Chain was left intact.
My comments refered to removing and replacing the covers while the engine is still in the car.

I had a noise like this a few years ago on my 3.2. I replaced the tensioner on one side and the noise never returned. This would be much easier than replacing the chain, might be worth a try.

The viscosity of my oil is 20W50. Here in Canada in summer time the temp rarely go over more than 90 F (30 C). My oil pressure at idle is at about 1.5...no less. Is it a big job to install that cam oil restrictors...??? The rattle occur only after a 20-30 min. ride on the highway and when I park the baby at idle...if I bring the rev over 1200-1500 RPM...the noise disapear...!!!

Not a bad idea Jerry...is the noise coming from you chain occur only at idle...??? I suspect a tensioner (oil press or unit) because it happen only at low RPM...

I had the same chain rattle at low rpm. It turned out to be stretched chains. http://forums.pelicanparts.com/porsche-911-technical-forum/291417-chain-tensioner-question-pics.html

zefsuper911: Re: Noise. I suspect tensioner failure. Open the chain cover and check the tensioner by compressing it. Wayne's book describes the procedure. If you replace the tensioner, do both sides.
While you are in there, check the ramps.
For chain stretching, check how much room is left for the tensioner-idler-travel. Take a picture of the idler in situ so we can tell you if it's coming too close to the case due to chain-stretch.
I don't recommend to just replace the chains.
If you feed new chains onto old chain sprockets, be prepared for this:

http://forums.pelicanparts.com/porsche-911-technical-forum/200267-new-chains-without-new-sprockets-read.html

Those are the sprockets on the I-shaft, not the cam sprockets. Why take a chance? :confused:

Thanks a lot for advice Gunter. I will store my baby in two days for a 5 month sleeping time (You know...Canadian !"/$%? winter)
So I will open both chain housing this week end and take pictures. I will post them and will wait for your advice. Again...thank you very much....Syl

Update...Took the baby to go to work this morning and the oil pressure is at 3 at idle with engine warm....definitly not an oil pressure issue....I took a stetoscope equiped with a rod connected to it (I use it sometimes to isolate strange noise in aircraft engines) and can hear (very clearly) the noise coming from the chain housing and there is something chafing there. Opening will take place this weekend and pics will follow.

Yup, time to open it up. Sounds like something was nice enough to give you a good warning.

I hate to add to the "while your in there".......
as others have said...
new chains, sprockets, check arm bushings, idler sprocket shaft, might as well make and install Jerry Woods slugs...these are good insurance

maybe if the sprockets are look very good you can reuse....I didn't do that. Look on the sides of the idler and main chain gear... you can maybe see that the chain is running straight of being pushed to one side

while your in there I guess put in new ramps...some ask if the master link type chain is an issue...I haven't read anywhere that someone said there was an issue. Those little "C" clips are small and fragile be careful with them

that's my 0.02

OK...Both timing chain housing covers are removed.
There is the right one...the one that make more noise:
http://forums.pelicanparts.com/uploa...1162148377.jpg

On the left one we can see that the tensioner end
has touched (but not damaged) the upper section of the housing.
And there is the left one...the more quiet one:
http://forums.pelicanparts.com/uploa...1162148416.jpg

Now I need advice...Please timing chain guru, get up...!

Zefsuper911,

I want to follow this thread so I am replying. I have the Bently Manual and 101 projects if you don't have them and want to borrow them.

Bonne chance

Thanks a lot Dave...I got the Bentley as well. For now I just want to have an experienced timing chain guru to give me some advice...How to know if it's the chain that is stretched or the tensioner that is bad ??? For sure something's wrong there. If possible I want to see a pic of how look a good chain and a good tensioner....Syl

I am no expert but from my previous research and from what I can understand, you need to pull back on chain on the sprocket and on lower chain to gauge the amount of play. Can you move it up and down with your fingure? The teeth seem good. It may be your auto chain tensioner that is not applying enough pressure when running. They rarely but sometimes do fail.

http://forums.pelicanparts.com/uploa...1162188040.jpg
This is what a new unstretched timing chain looks like.
Your timing chains are all stretched out. Time to replace.
Carefully inspect the sprockets, they may need to be replaced as well.

As I can see, the piston's lever has more play than mine at the upper side of the housing...

Also, your tensioners are nearly fully extended, more on the right it appears.

Patton...Do I need to change the tensioners along with the chains...How to see if they are serviceables to continue theirs job...?

As noted you've run out of travel as the chains are stretched.

Master link swap not hard but make sure your cam(s) are "locked down" before you do the swap.

Upgraded Idler arms are nice if not already in place. Change all the ramps too. You're there, why not go all the way?

If you change out to new oil fed tensioner remember to "drown them". Place them in oil and pull the pin. This allows oil intake and they will be a much safer tensioner to start the car with. Yes, they are oil fed but they don't have much if any in them when new. You can compress them and re-fit the pin when the time comes to install in the car.

Plan on an afternoon (all) and take your time.

Good luck,

Tom

You basically test how easy they are to compress. They should be tight (relatively hard to compress). Read as many of the previous threads on this subject which will help you determine.

I reused both of mine when I replaced my chains after testing them. Also, remember gunter's advice.

My take on it: The chains are stretched to a point where the tensioners are approaching max travel. The tensioners may be good; the resistance to compression will tell you; tie up the chains to maintain cam timing and use channel-lock pliers to compress. Stiff is normal, soft is no good.
Chain-stretch over a long time is normal; what is your mileage?
Along with chain-stretch comes sprocket-wear.
The cam sprockets, and idler sprockets, are "driven" and can be accessed, inspected and replaced with the engine in place. They usually can be re-used.
The chain sprockets are the "drivers" on the Intermediate Shaft and can only be replaced by splitting the case meaning: A complete rebuild.
That is the time when you find out what kind of P/C's you have which makes a big difference on how to proceed. Porsche used 2 types of P/C's without any sequence. It’s the luck of the draw!
If you have Mahle (Nikasil) within specs, good, just get new rings and you just saved about $3k.
But, if you find Kolbenschmidt (Alusil) re-ringing the pistons is almost impossible; very few people have taken a chance. Do a search on this!
The cost of new Mahle 95mm P/C's is almost the same as going to bolt-on 98mm P/C's to convert your 3.0 liter into a short-stroke 3.2. I have 2 engines now: One 3.0 with 95mm Mahle P/C's and a 3.2 SS with Mahle 98mm P/C's. Planning to swap soon.
Along with the larger P/C's, regrind your SC-cams to a 964-profile, install SSI's and now you added a respectable ~40 horses.
Some people take a chance and feed a new chain onto worn chain sprockets contrary to mechanical principles.
While rebuilding my 3.0, I was talked into doing that. What a costly mistake! What a disappointment when you have to tear down a freshly rebuild engine after 15K miles when you find the teeth from the chain sprockets on the bottom of the case. Sh$t!!

The decision is yours. Keep in mind that, when the chain is that stretched, along with sprocket-wear, it also means that the bearings on the I-shaft are worn meaning: the big Alu-gear on the I-shaft can be damaged because it's getting too close to the steel gear on the crank; not enough backlash!
(These 2 gears determine the 2:1 ratio between crank and cam)
I suspect that your engine has high mileage?
As you can see, a stretched chain means that the engine run for a long time, other components need to be changed, time for a rebuild.
Your tensioners may be alright, check how they compress according to the books. (I use large channel-locks)
Get a Bentley Repair Manual, and Wayne's book on engine rebuild, and then make an intelligent decision.
New chain on worn sprockets? Never again for me. :(

Hope this helps. :)

Let us know what you decide. SmileWavy

Thanks a lot for advice Gunter...the car\engine show a 92000 miles or 140000 km. I will give a look to the tensioner and the sprockets tonight.