Timing belt teeth gone and gear spins freely

wdw · Jul 31st, 2004, 09:37 AM

Okay, I've had my '88 Sentra since new /w about 180K miles. It's been a great, trouble free car until now. I was driving @ about 20MPH when the engine just dies, so I thought it was a broke timing belt after hearing the
engine when I tried to re-start.

Took the timing belt cover off, but the belt wasn't broke. Had someone
crank the engine and noticed the timing belt wasn't moving. Stripped teeth?
Yep. Removed the belt and found the teeth around the gear nearest to the crank pulley at the bottom were striped. I can spin that lower gear/sproket by hand and it does not turn when the engine is engaged by the starter. Can't turn the bigger gear by hand that handle the valves.

What's the deal? Any ideas?

Thanks
wdw

Myetball · Jul 31st, 2004, 10:35 AM

Well, it's obviously time for a new belt. Also, there's a high probability you bent some valves. You can try lining everything back up and putting a new belt on. If the engine doesn't run right you'll have to pull the head and get the valves fixed.

Just reread, sounds like the crank pulley key is sheared. Have to pull the pulley off and replace the key.

SPEEDO · Jul 31st, 2004, 03:14 PM

a Belt couldnt have stripped the teeth on a gear, you had to of sheared the crank key. before you got to start it back up (after the fix) turn the engine over by hand.... just to make sure you didnt bend anything

wdw · Jul 31st, 2004, 08:23 PM

Quote:

Originally Posted by SPEEDO

a Belt couldnt have stripped the teeth on a gear, you had to of sheared the crank key. before you got to start it back up (after the fix) turn the engine over by hand.... just to make sure you didnt bend anything

Should have clarified further. The teeth on the belt stripped, not the on the gear. Also, should I be able to turn the upper gear that drives the valves by hand?

Crazy-Mart · Jul 31st, 2004, 09:24 PM

cam gear is very difficult to turn by hand .. trust me !! ... the crank one is much easier as theyre aint no valve squiched with a spring holding it like the cam one does

nispulsar · Aug 3rd, 2004, 08:43 PM

If that is the origional belt on there then the teeth just probably wore out, I have seen that a few times before, they just get brittle, and then they eventually just break off. Good chance you bent some valves, but you could try to change the belt first, it is easy on those engines.