IceWater

OK, so my '93 968 suddenly had no power below 2000 RPM or so and was making a dull clackety sound in that range. Pulled off the belt cover and saw that the timing belt is starting to fall apart. Its not broken, but some of the teeth are separating from the belt. So I assume that the belt slipped a few teeth and screwed up the valve timing. The dealer was supposed to have replaced the belt before I bought the car (40,000 mi ago). Looks like yet another way US Auto Exchange in Boston has f**ked me.

So here's what I need from y'all, as I will be doing all of the work myself:

1) What are the chances that the timing was off enough to damage the valves? It ran fine from 2000-2500 rpm and up.

2) Is there an easy way to inspect the valves?

3) Should I rent the belt tensioning tool from Pelican Parts or is there an inexpensive tool that I can buy that will work well?

4) Can someone email or fax me the procedure from the repair manuals? This is one that I would rather not wing.

5) Are there any other things that it makes sense to do at the same time?

6) How long should I expect the job to take and how frustrated should I expect to get?

Thanks in advance for the help. My email addresses are:

tgurski@dekaresearch.com (business hours)
tqgurski@yahoo.com (home)

Thanks again,
Tom

Adrian

Dear Tom,
Jumping one tooth is enough to damage the valves. I really do not think you have any choice but to remove the head and carry out a proper inspection. In this case you are going to have to be safe rather than sorry. I have personally never heard of anyone having this happen, myself included many moons ago and get away with it. I wish I could offer more helpful advice but the damage is going to be on the underside of the valves and possibly the top of the pistons. What we call the mushroom head affect. Anyway, you can mess around and hope for the best but the fact that you had the clattering noises is enough for me.
Ciao,
Adrian
911C4
944

Max

You could call around to a few auto shops in your area and ask if they own a bore scope (500.00 USD took). If you find one that does they can look though the spark plug hole to see if you have any indents on the piston crowns from were they met with the valves.

Maybe one hour labor.

HTH

Max

IceWater

Thanks Max. I actually already did that. I brought one home from work and took a look. Didn't see any evidence of the valves hitting. That, combined with the fact that it didn't have any loss of power in the upper RPM range, even though the timiming was off, leads me to believe that I didn't damage the valves. That's what I'm hoping at least. Once I get everything back together I'll do a compression test and see if its normal.

Thanks again,
Tom