Odds on a slipped timing belt....
#1
Odds on a slipped timing belt....
HI Everyone,
I realize this is a strange first post, but I'm wondering if there is any chance that a slipped/sheared timing belt might not have caused significant valve damage. Appearently, the belt slipped at a stoplight. (Obviously, I will pull the head to inspect the damage when/if I have the car in a garage), Car is an 85.5 944.
Thanks,
Mike
I realize this is a strange first post, but I'm wondering if there is any chance that a slipped/sheared timing belt might not have caused significant valve damage. Appearently, the belt slipped at a stoplight. (Obviously, I will pull the head to inspect the damage when/if I have the car in a garage), Car is an 85.5 944.
Thanks,
Mike
#2
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Chances of it NOT bending at least two valves..................0%. BET on it. I've heard of "stories" that one can have gotten lucky, and not bent any valves, but..........don't believe it. Interference fit engines are, just that. Sorry. You can bend valves just by turning the engine over by HAND, if the timing isn't close enough.
Have you "verified" the timing marks on the flywheel and cam gearto make sure this IS the case, when everything is at TDC? The belt actually broken?
By the way, welcome!............sorry this would have to be your first post.
Have you "verified" the timing marks on the flywheel and cam gearto make sure this IS the case, when everything is at TDC? The belt actually broken?
By the way, welcome!............sorry this would have to be your first post.
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Mike, Welcome!
Regarding your timing belt, if it just slipped, as opposed to a complete break, you shouldn't be completely screwed. From what I've read here, a slip won't do as much damage as a comlpete break. Chances are your top end needs help,( machine the head, maybe, or replace it, definitely the vavles will need attention, not sure about anything above the valves. Someone else may help more.) Chances are your engine's bottom end is okay. However, check this out. Save yourself the frustration.
But I take it your car doesn't start, or if your lucky, runs like crap. Am I right?
Check the archives,(search this forum.)
Best of Luck,
-the kid
Regarding your timing belt, if it just slipped, as opposed to a complete break, you shouldn't be completely screwed. From what I've read here, a slip won't do as much damage as a comlpete break. Chances are your top end needs help,( machine the head, maybe, or replace it, definitely the vavles will need attention, not sure about anything above the valves. Someone else may help more.) Chances are your engine's bottom end is okay. However, check this out. Save yourself the frustration.
But I take it your car doesn't start, or if your lucky, runs like crap. Am I right?
Check the archives,(search this forum.)
Best of Luck,
-the kid
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Exactly what Ken said is the truth. How long had it been since the timing belt was done? just so ya know, the 944 timing belt is a 30K replacement, with a 10K tension...
I hate to hear you had to suffer that, it's no fun.
I hate to hear you had to suffer that, it's no fun.
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Tolerances in there ARE tight (and other places also). But so are many other........interference fit engines. Even the Fiat X-19 I had some years ago. Boy did I learn THAT the hard way on that car.
I've picked up two cars (944's) that had belts break, or "slip". Uhhuh! bent valves! One had a broken valve, and destroyed the top of piston and the cyl. wall. 45K miles , I believe is what the factory says to go, but, most around here are definately paranoid enough to go the "safe route" and replace after 30K. Check out ALL belt rollers and waterpump on teardown. Good luck to ya!
I've picked up two cars (944's) that had belts break, or "slip". Uhhuh! bent valves! One had a broken valve, and destroyed the top of piston and the cyl. wall. 45K miles , I believe is what the factory says to go, but, most around here are definately paranoid enough to go the "safe route" and replace after 30K. Check out ALL belt rollers and waterpump on teardown. Good luck to ya!
#11
Thanks for all the quick responses... To be clear - a number of the timing belt's teeth have sheared off at the crank sprocket, allowing the sprocket to spin freely when cranked, with zero movement of the timing belt. Furthermore, the car has been cranked many times since the failure (not by me - sigh). So... How about odds on bottom end integrity??
P.s. I would never be careless on an item like this....I drove 300 miles today to pick up a 944 (my first) which "only" needed a fuel pump change (which was to be done by the seller, of course). Unfortunately, I discovered that "needs a fuel pump" actually meant his timing belt came completely off and he had no idea how to diagose that problem. I'll be towing it home tomorrow. At least he was honorable about it and I got the car for a steal as a result....
P.s. I would never be careless on an item like this....I drove 300 miles today to pick up a 944 (my first) which "only" needed a fuel pump change (which was to be done by the seller, of course). Unfortunately, I discovered that "needs a fuel pump" actually meant his timing belt came completely off and he had no idea how to diagose that problem. I'll be towing it home tomorrow. At least he was honorable about it and I got the car for a steal as a result....
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My "S" did the same thing in the parking lot of HEB right after I started - It failed simply because I installed it improperly though.......