timing belt?


kmohr3
10-10-2004, 10:57 PM
Has anyone with the 3.5 L engine had a problem with the timing belt yet? Has anyone had one replaced? I haven't seen it mentioned in any of my service literature.

Being a auto technician myself I can imagine what would happen if this belt broke or jumped time. On the other hand I haven't heard of one breaking yet.

Does anyone know if this engine is used in any other GM product?

Thanks,
Karl

jmlangeveld
10-11-2004, 09:38 AM
The 3800 V6 has a timing chain with something like a service life of 250,000 miles. This is nice because you don't have the cost associated with replacing timing belts (i.e. Honda). Does the 3.5 also use a chain? If so, you shouldn't have to worry about it unless you are having problems.

The 3.5 V6 is also used in the Oldsmobile Aurora.

paulkramer
10-11-2004, 02:39 PM
Actually, I was reading somewhere that the primary belt should be serviced....I'll have to look that up....don't recall the mileage recommendation.

At least a Honda engine will last long enough to require a timing belt replacement! And the rest of the car to boot!

Ruley73
10-11-2004, 07:24 PM
The 3.5L DOHC V6 does not have a timing belt. It only has a timing chain which is supposed to last the life of the vehicle and under normal circumstances it should never need to be changed. The 3.5L DOHC V6 (vin H) engine was only available in 1999-2002 Intrigues and 2001-2002 Auroras and is no longer used by GM due to the demise of Oldsmobile.

Also, the maintenace interval of a timing belt is typically 60K-100K miles depending on the vehicle and should be done as preventative maintenance before they snap and cause major engine damage. But once again, the 3.5L DOHC V6 (along with most other GM engines) uses a timing chain.

I'll bet that the belt you read about was the serpentine belt which drives the water pump and accessories (alternator, A/C, power steering, etc.).

JTrujillo86
10-11-2004, 08:15 PM
Even if there is a problem with the timing chain (which is very rare and unlikely) there wouldn't be too much damage done to the valves because this is a non-interference engine; the 3.8 is anyway. I'm not sure about the 3.5. The 3.5 may be an interference engine because it's a DOHC design...I'm not sure.

Jeremy

paulkramer
10-12-2004, 08:25 AM
Sorry I was referring to the chain. Somewhere (I haven't had a chance to look it up yet) it recommends replacing the 3.5 chain somewhere around the 60-100 K mark.

kmohr3
10-13-2004, 06:22 AM
Actually, I'm getting more info, bit by bit. There are 3 chains total. One main chain to drive the 2 intake cams and balance shaft. Then 2 more smaller chains that drive the exhaust cams off the intake cams.

Being a mechanic I feel that I have to "learn" every model that I own. Wish I could find a half decent service manual that covers the 3.5 Litre.

paulkramer
10-13-2004, 08:45 AM
Have you tried Chilton's? They have a fair service manual. And, of course, there is always the official service manual available from Helm, Inc. Chilton's guide is around $20; Helm's around $125.

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