164 Timing Belt Teeth Broke Question

RPR164 · #1 (**permalink**) 05-30-2009, 07:42 PM

Here is a stupid question.

Today on the freeway my 91 164 stopped running. Once I got off the freeway I saw the timing belt was in tack but not turning. I figure I have at least a few bent valves. When it happened I didn't really hear anything mechanical go boom! I always thought when valves and pistons collided, that I would hear a loud uncomfortable mechanical noise followed by silence. The engine turns over with no unexpected noises. Cams don't rotate. Able to move cams a little by hand. Did not try to move them more than 2 or 3 teeth. The part that irkes me is the belt has about 25K & is dry as far as I can currently see (maybe too dry) . This was to be the superior German made Alfa OEM belt.

Now for my stupid question. The car is about 40 miles from home. I had the car towed to where a friend of mine works. I can work on it there for about a day. But cannot expect to R&R the heads. Is it possible to change the belt and expect the car to run at all? Typically, how many valves get bent? Push rods?

Any info appreciated.

Thanks

Any information appreciated.

**Alfissimo Int.** · #2 (**permalink**) 05-30-2009, 08:05 PM

Quote:

Originally Posted by RPR164

Here is a stupid question.

Today on the freeway my 91 164 stopped running. Once I got off the freeway I saw the timing belt was in tack but not turning. I figure I have at least a few bent valves. When it happened I didn't really hear anything mechanical go boom! I always thought when valves and pistons collided, that I would hear a loud uncomfortable mechanical noise followed by silence. The engine turns over with no unexpected noises. Cams don't rotate. Able to move cams a little by hand. Did not try to move them more than 2 or 3 teeth. The part that irkes me is the belt has about 25K & is dry as far as I can currently see (maybe too dry) . This was to be the superior German made Alfa OEM belt.

Now for my stupid question. The car is about 40 miles from home. I had the car towed to where a friend of mine works. I can work on it there for about a day. But cannot expect to R&R the heads. Is it possible to change the belt and expect the car to run at all? Typically, how many valves get bent? Push rods?

Any info appreciated.

Thanks

Any information appreciated.

RPR164 · #3 (**permalink**) 05-30-2009, 09:12 PM

I guess I didn't word my question correctly. I know that its virtually impossible not to have bent valves. My question was if I throw a new belt on, what are the chances that the car may become drivable whether on 3 or 4 cylinders just to get it home?

As for the belt, the way it looks right now, it appears that's what failed. The belt is nice and tault. I even rotated the cams slightly backwards and forward, the belt remained tault. If the tensioner failed, I think I would have loss the taultness. But I'll find out for sure when I take it apart. If the cams are out of time with each other maybe the tensioner did allow the timing to slip.

Thanks for your response. I'll keep those heads in mind.

**AlexGS** · #4 (**permalink**) 05-30-2009, 09:43 PM

Maybe there is no problem with the belt at all and it was the crank pulley drive key that sheared? That would be an easier 'fix' to get it running again (maybe). Just as likely to have bent valves of course.

I think it might be a bit of a job to fit a replacement belt just to get it home - you have to remove part of the cooling system and the auxiliary drivebelts, and then deal to that huge (38mm?) crank nut. Easy enough if you have air power and an impact gun at your disposal - not easy otherwise.

I suppose if it does run at all, you could always unplug injectors for cylinders that have no compression.

I dread this sort of thing happening and I do feel what it's like for you.

I guess at least you made it off the freeway and didn't become a stationary hazard...

-Alex

RPR164 · #5 (**permalink**) 05-30-2009, 09:55 PM

Quote:

Originally Posted by AlexGS

Maybe there is no problem with the belt at all and it was the crank pulley drive key that sheared? That would be an easier 'fix' to get it running again (maybe). Just as likely to have bent valves of course.

I suppose if it does run at all, you could always unplug injectors for cylinders that have no compression.

I dread this sort of thing happening and I do feel what it's like for you.

I guess at least you made it off the freeway and didn't become a stationary hazard...

-Alex

**AlexGS** · #6 (**permalink**) 05-30-2009, 11:08 PM

Quote:

Originally Posted by RPR164

The alternator rotates when I crank it.

RPR164 · #7 (**permalink**) 05-30-2009, 11:29 PM

Quote:

Originally Posted by AlexGS

I didn't mean that pulley - I meant the toothed pulley that drives the cambelt.
-Alex

ChazzyD · #8 (**permalink**) 05-31-2009, 08:45 AM

I think you will have to end up towing it home to work on it properly. You have a lot of work ahead of you to fix this. Just bite the bullet and bring it home for repairs.
Charles

**Alfisto Steve** · #9 (**permalink**) 05-31-2009, 01:47 PM

I doubt the square metal "key" in crankshaft for front pulley and timing belt cog pulley is sheared just under cog gear. Chances are all the belt teeth are sheared off at crankshaft cog gear. Now why they sheared - old age of belt, frozen cam pulley or tensioner bearing pulley or foreign object jammed in belt and cam pulley system is the question only a good visual examination will reveal.

I suggest you tow the car home and open it up for a close inspection.