Timming chain jumped a tooth???

[HGturboT]

My buddy is in the process of buying an 87 TTYPE with a bad trany and the timming chain jumped a tooth. My question is do you guys think any internal damage could have happened? The timming is off (he tried to do the chevy timming) but it sounded like it wanted to fire (compressing) so i'm assuming it could be ok We plan on pulling the heads when he buys, but I guess i'm hoping to read some positve feed back

Thanks, Danny

 

[FastRegalWE2]

if it is only 1 tooth, I would say no. It has been my experience with other engines with a 1 tooth jump you can sometimes move the plug wires over 1 spot and make the car run good enough to get it home, with a mechanical distributor of course. I would bet it is fine as longs as it wasnt 3-4 teeth, even then it may be ok. It is the overhead cam engines that the P/V clearance is VERY tight on and 1 tooth can mean disaster

 

[Nick Micale]

Would think the first thing you want to do is pull the timing cover? Having done LOTS of Buick V-6's, have never seen a chain "jump" a tooth.

Seen some very loose chains but could not even get them over a tooth when prying. What happens is the nylon gear gets very worn and timing then can be off far enough so it will not start. If compression is low, this can be due to cam timing being way out.

Do a timing chain first, then run a compression test. The valves should not have interferred and bent in excessive wear.

 

[Ormand]

"he tried to do the chevy timing"?? What does that mean? The timing on the '87 turbo Buick is controlled by the ECM, it is NOT adjustable. It can be right or wrong, but not adjusted. The cam sensor can get out of adjustment, and that will sometimes get the firing sequence retarded by exactly one cylinder. In that case changing the plug wires would be a temp fix. And the crank sensor can be off, which will mess up the whole sequence. (If the crank sensor was adjustable, that would allow for timing changes, but never seen it done)