Noisy chains or valves? - 80SC

[Malcolmh]

I replaced the clutch in my car over the winter and adjusted the valve clearances. The car now seems noisier than I remember last year (I only ran the car for 500 miles before the clutch went). Several people have said, 'Is that how a 911 sounds?' My friend, a mechanic, reckons its normal but has only worked on Beetles not 911's.
I had another friend check my clearances after I adjusted them so hope they are ok.
My question is this, how can I tell if the noise is normal valve type or are the chains on their way out?

[Malcolmh]

P.S. I think the car has had a tensioner update as there are additional oil lines into the chain housing!

[john walker's workshop]

a long screwdriver with the handle pressed to your ear makes a good stethoscope. put it on the chain housings and valve covers.

[Malcolmh]

Will do this tonight....so whats worse....Chains or valves?

[Nickshu]

I have not heard of any chain failure on an SC...but anything is possible.

I would also consider the possibility that one of your plastic chain rails has broken and is allowing the chain to slap something that it should not. Poorly tensioning tensioners (do you have pressure feds?) will allow some slack in the chain. The chain can then slap the rails (or whatever else!) hard and make noise as well as break the plastic rails. If this has been going on for long enough, it could damamge your chains as well.


Hope this helps.
Nick.

------------------
_ _ __ _ _
Nick Shumaker
1982 911SC Coupe
nickshu@yahoo.com
PCA -- Rocky Mtn. Region

[Malcolmh]

Maybe I am tone deaf or just not used to doing this but I cant differentiate between either noise...maybe they are both noisy but how nosiy should they be????

[Malcolmh]

I think it has pressure fed tensioners going by the extra oil lines!!

[Malcolmh]

Nick....plastic chain rails? Can you point me to the Pelican part(s) for this?

[Jens Wendorff]

Here you go:

http://www.pelicanparts.com/catalog/shopcart/911M/por_911M_engine_main.htm

Check page 2 "911 Chain ramps..."

Jens

[O2Cooled]

If the noise comes above idle, i.e 1500+, then chances are that its the tensioners. I had a hydraulic tensioner that was doing the same thing. I opened up the right side chain cover to inspect it. Everything was in proper order at first glance, but when I took off the tensioner, I found out that a small piece of aluminum plug that came off the tensioner was causing the reduction in oil pressure in the tensioner.
In terms of repairing, the chain is a lot cheaper and easier to replace. Chains cost about $45 and hydraulic tensioners (ea) cost about $200. In terms of complete failure, either one will result in a catastrophic engine damage. I suggest not driving your car until you pinpoint the problem. A 911 with a properly adjusted valve lash should not be too noisy that would warrant someone to ask if thats how a 911 is supposed to sound like. Exact valve clearance is critical, as either too loose or too tight would make certain noticeable noises.
Good luck.

[Malcolmh]

Cant see my last post......what part are the chain rails??

[Malcolmh]

So why is there a choice of colour and quantity???

As an aside, is anyone else loosing their Username/Password and has to login every time you put up a post or reply?

[Malcolmh]

BTT