Timing Chain/Balance Shaft Chain Issue?


#1

I recently bought a 2002 Saab 9-3 SE with 101,000 miles from a Saab dealership for a pretty good price- 8K [it runs well and looks new]. After a pre-purchase inspection a nearby mechanic [not a Saab specialist] said he heard a noise in the engine he couldn’t account for but his guess was it was the timing chain. I told the dealership this and they took a look at it and said they didn’t hear anything and these engines just sound different. I accepted that and bought the car.



So a few weeks later I’m having the rotors replaced at an indy Saab shop and I ask the owner/mechanic to take a listen and he says he hears the timing chain and recommends replacing that and the balance shaft chain [$2300- and that’s the cheapest estimate I could find]. Before going to the dealership with this I stopped by that same indy Saab shop to get some advice as to what to tell the dealership and the service manager [diff guy] and another mechanic say that though they hear the noise too [not put on a rack] there’s no need for immediate action and that I’m fine for another 10, 20 or 30K miles [they’ll just take a listen at every oil change to see if its getting worse]. The service manager also told me that if I were to just drive in there and ask if the timing chain needed to be replaced he’d say no. And, as expected, the dealership service manager, my salesman and another tech say they hear nothing wrong with the chains.



Additionally- after getting gas at a nearby service station this past week I asked a mechanic [not a Saab specialist] to take a listen [NOT on a rack however] and he says he can hear nothing wrong with the chains or the engine in general [he also said that in 30 years as a mechanic he may have seen only one bad timing chain on a Saab]. Now, if I didn’t have these mechanics saying there was something wrong I wouldn’t think there was a problem. Whom to believe? Is ignorance bliss? Should I go to the other dealer in the area and see if they can diagnose the problem if there is one? Any and all opinions/recommendations welcome. Thanks.


#2

Timing chains make noise. That’s why there are timing belts on some engines. Checks can be made to determine how much wear has occurred in a timing chain. A wrench can be put on the crankshaft and turned through the “play” range. An experienced eye can determine if the play is excessive. A timing light can be used to see how much play is in the timing. Too much timing variance would equal too much wear of the timing chain. You might find one mechanic who can/will do these checks.


#3

Thanks Hellokit,

The car is at the shop now and I told them to open the valve cover and see how far the tensioners are extended. I was told by another mechanic that this is a good way to gauge timing chain wear. I also asked them to check for an oil sludge problem which will help me to know if there is a problem leading to timing chain wear.

Do you think this will be enough or should I pass on your recommendations to them on how to diagnose this problem?

-WaSaab


#4

What you heard from the other mechanic is about the same thing: watching for the first movement of the valve gear as the crankshaft is turned back and forth. How far the crankshaft turns until the valves start to move, is the amount of timing chain wear. A timing chain is expected to last the life of the engine, though they will wear, along with the rest of the engine.