I was just leaving for work when the car stumbled, lost power and made a quiet ticking until I hit the clutch and coasted to a stop. Not being sure what exactly happened I tried to restart the engine and to my horror got the smooth uninteruppted whine of a starter working against no resistance. This timing belt was only 39,000 miles old too! Is there any way to find out just how much damage has been done without pulling the head? I have a t-belt kit and an available engine out of the 89 I'm parting out but I'd like to minimize the work and cost. I'd rather just replace the head than do a complete engine swap if I can help it, especially since that engine has a broken oil pan...
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Why are you sure that the timing belt has snapped? If the belt had broken, your starter would have lots of resistance.Originally posted by Tangent
Sounds more like a problem with the starter. Try turning the engine over by hand first. If the crank turns but the cam doesn't then you have a broken belt. You can also remove the valve cover and seen if you can see the belt on the cam.
If the belt has broken then you have at the very least some belt valves. There is no way of knoing unless you pull the head.
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If it isn't the t-belt it's something way more serious then. I verified that the starter is engaging by opening the hood and watching the radiator fan spin when I crank the engine. If valves were getting hit how loud would it be?Comment
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It would probably be nasty sounding unless the valves have broken in which case it probably wouldn't turn over.Originally posted by Tangent
Remove the valve cover and check if the vavletrain turns when you crank the engine. Also look for broken rocker arms. You can also see the belt with the cover off.Comment
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Well, the timing belt is definitely gone. It also broke one rocker arm. I guess now I have to hope I get lucky and that valve didn't damage the piston... Unfortunately I can't check that today. I don't have a torx socket set and the head bolts on mine have been replaced with the torx bolts. I also don't want to start pulling the head on the parts car in case the piston is dorked and I end up replacing the whole engine.Comment
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In my experience, when the belt breaks it will bend most of the valves just enough to loose compression, unless you were hauling ass in which case it breaks rockers and the rocker shaft journals in the head. This is why you had the sound of the starter running with no resistance.Adam Fogg- '88 M3
Common sense- It's the new 'gifted'Comment
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I definitely wasn't hauling ass... I had just shifted in second gear after leaving my driveway, I was probably only at 1900 rpm. Oh well, with the broken rocker it's gone from a t-belt replacement to a head swap anyway, I just hope the piston's OK.Comment
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Originally posted by Tangent
In my experience, most timing belt breakages occur at either idle or low rpm.
Even if the valves have nicked the piston you are probably ok.Comment
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Cool, the pistons are pretty tough then?Originally posted by arsevaderComment
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They are reasonably tough and they have more mass than a valve so the valve always loses. Even if you get a gouge on the piston face it's usually not that bad.Originally posted by Tangent
Unless of course you punch a hole in one. But I'd be more likely to think that with a new head you'll be fine.Comment
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Lol, I notice you just changed your signature...Comment
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Haha yeah, been meaning to for a while and this remainded me.Originally posted by Tangent
The Volvo is a belt driven interfernce engine too which seems to be more and more rare these days.Comment
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Yeah I gotta tell ya, I do miss having a timing chain... They might stretch after a couple hundred thousand miles and throw off your valve timing a bit, but chances are pretty good they'll never break on you.Comment
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