I brought my '97 Saturn SC2 (102K mi.) in when I noticed a grinding/rattling engine noise. This car has been well maintained, gently used, and almost completely trouble free (knock on wood). My mechanic said my timing chain (Saturns have a metal chain) has just slightly stretched a bit over time, and unless I had money to waste at the moment, not to worry. Because he’s never seen one break, and it?s not really harming anything by operating as is. He said if it starts to sound like a typewriter, come back. Which of course I began to suspect out of paranoia the very next day (hmm, would that be classified as typwriter-ish?!?!)
Regardless, I?m confident in my mechanics diagnosis, but I?m not sure I should just add this noise to the acceptable symphony of charming hums and rattles that are part of a 12-year-old Saturn. Internet chat boards are riddled with stories of stretched chains causing damage to valves, etc. when left unattended to, and chains breaking, causing thousands of dollars of damage to the engine. As I?m currently unemployed I?d like to believe I could put this expense off, but I certainly can?t afford extensive repairs and or an accident on the road that could have been prevented. Help!?! I need a second+ opinion.
Your mechanic is partially right, a rattling timing chain is not about to break immediately. Hoever it should be fixed as soon as possible. I had the same happen on my V8 Caprice at 200,000 miles some years back. The total cost was about $250, of which $50 was parts.
Thanks Docnick. I did call back an speak to the mechanic about discussion I found indicating that this type of noise more likely signaled the need to replace the tensioner and clean out any clogged chain oil valves (around 100K) rather than replace the chain, because (as my mechanic agreed) the chain will likely outlast the car. In response though, my mechanic repeated that he knows I?ve taken good care of the car otherwise (i.e. regularly changed the oil). So I should still NOT worry about it until it gets noticeably loud.
In my on-line search I also gathered that this type of repair on a Saturn S series would run closer to $500, but a broken chain would possibly cause $1500-2500 worth of damage.
So I still have a dilemma, trust my seemingly candid mechanic and save my wallet, or trust my gut and potentially save my car.
Any other thoughts? Anyone else care to weigh in?
I would definitely have the tensioner checked out and replaced if necessary, and any debris removed. A failing tensioner (even if the chain is OK) can make the chain jump teeth, resulting considerable valve damage. My Chevy had a simple chain and sprocket set which is replaced as one unit, there was no tensioner. Spend the $500 and sleep comfortably!
Your mechanic is being very helpful here, in my opinion by stating facts.