Kelly Holzhauser

Greetings all,

The plastic gear on the tensioner roller broke into many pieces on my '87 na 944 causing the timing belt to slip (a lot). Of course, the engine stopped instantly. After towing the car home I decided to check the timing and balance belts (they were replaced about five thousand miles ago). They were intact and seemed fine (loose, but otherwise fine). That was when I noticed pieces of the tensioner roller everywhere. I aligned the timing mark on the top of the flywheel and checked the alignment on the camshaft sprocket. It was off about ten teeth!

If I assume it only moved ten teeth, and didn't spin a while before resting ten teeth away, would I still have valve damage?

If my valves are bent, would I still be able to turn the camshaft sprocket by hand?

I'm just hoping for the best before I decide to take off the head and take it to a machine shop. Any comments, advice, or help would be greatly appreciated.

Thanks,
Kelly Holzhauser

tinman944

you valves are bent . yes you will be able to turn the cam

tifosiman

Valves are more than likely bent if it was 10 teeth off. Sorry~

Kelly Holzhauser

Thanks, guys.

I thought I was good after just having the belts replaced 5,000 miles ago. I guess not.

bummer

Techno Duck

Just curious, what is the history on the tension roller? Was it replaced the last time the belts were done?

MM951

Thats how I bought my mint 84. Tensioner roller seized spit bearing all over my timing area and bent 3 valves. $1200 later (including cost of car) I have a mint n/a.

Since you will be needing new belts/rollers anyway buy the kit put it on see if she starts. You may be lucky and it will fire up. More likely you'll have a bent valve or 2 and then buy a head set and get your head off to a machine shop..

95Juan

+1

Kelly Holzhauser

Yes, supposedly. I know they're supposed to be changed every other timing belt change. I had the belts replaced, professionally, the time before the last time. I was charged for the rollers but who knows if they actually replaced it. I replaced the belts 5k miles ago, myself. I thought about replacing the rollers, but figured every other time was sufficient. Now I feel stupid. I'll replace them every time, from now on.

Anyone know of a good machine shop in Northern Virginia to take the head to?!!!

Mike C.

I really think every other time is fine based on my experience. However, you do need to be sure they are actually replaced.....

dgz924s

I had the timing slip as well and now looking for a new engine as I think I blew a hole in a piston....My timing was not off as much as yours. What gives me the thought I blew a piston is 0 PSI in cylinder 1.

Too late for a compression check(engine locked up) so grab the tools and pull the head, the results will be there. Hope it is not as bad as it can be!!

GL!
Dal

Stan944

If you put the tensioner together and the belts, you should be able to do a compression test. Then you will know if (or which) valves are bent. Because the belt slipped only 10 teath, only one or two valves would be bent if any.

sharky47

Yep - do a compression test - you never know, might get lucky.

Odds are you bent some, take this time to replace the rollers, WP, and front seals. I will be doing this on my next belt change, which I may just go ahead and do early.........

Kelly Holzhauser

Thanks for all the input. You guys are great.

I'll run a compression test when the parts arrive. It may save me from having to pull the head. It'll at least give me an idea of the damage, if any (hopefully not), and I'll go from there. I'll keep my fingers crossed.

Thanks again.

Rock

This happened to my girlfriends 951!!!

Just put that back together, it runs. Id be glad to help you too. Where is Front Royal?

Kelly Holzhauser

Rock,

Front Royal is only about 50 miles west of Ashburn, right off route 66. Did you just put the roller back on, align the timing, and everything was okay? Or, did you have to take the head off for valve work? I may take you up on the help offer. The roller should arrive Friday and I'll do the compression check. If that's fine, I'm good. I've never taken the head off.