New noise coming from near left cam gear distributor [SOLVED!]
05-04-2011, 12:43 AM
#46
Rennlist Member
Thread Starter
I've gotten a loaner flywheel lock lined up (thanks Greg & Don for the offers). As soon as I get the belt removed, the tensioner assembly is coming off. I'll report back with details & pics.
We all need to know if Dave's getting his beer.
I hate to say this, but my beer's on two completely unrelated issues: a pump bearing getting ready to seize and a bad tensioner arm bushing (although I'm not ruling out "improper replacement technique"
)
All I can say is I'm glad I went in before the sound got worse and/or something happened that would have really ruined my day/week/month/year.
Oh, and one other thing:
The depth of knowledge, wisdom and the invaluable sense of community that exists within & beyond this forum makes owning these cars an absolute pleasure.
We all need to know if Dave's getting his beer.
I hate to say this, but my beer's on two completely unrelated issues: a pump bearing getting ready to seize and a bad tensioner arm bushing (although I'm not ruling out "improper replacement technique"
)All I can say is I'm glad I went in before the sound got worse and/or something happened that would have really ruined my day/week/month/year.
Oh, and one other thing:
The depth of knowledge, wisdom and the invaluable sense of community that exists within & beyond this forum makes owning these cars an absolute pleasure.
05-11-2011, 09:37 AM
#48
Just putting this out there.
I've got an '85 Euro here that had a similiar nose from the passenger side of the engine, could not isolate it so dug in to the timing belt. Once the tension was taken off the passenger side cam, it was obvious what the issue was. Slack bolt holding the cam gear on, had been pounding the cam shaft and cracked it.
I've got an '85 Euro here that had a similiar nose from the passenger side of the engine, could not isolate it so dug in to the timing belt. Once the tension was taken off the passenger side cam, it was obvious what the issue was. Slack bolt holding the cam gear on, had been pounding the cam shaft and cracked it.
05-12-2011, 05:09 PM
#49
Rennlist Member
Thread Starter
AND THE BEER GOES TO...
Sean, I winced when I read this, but it was a very valid suggestion...
..but this one's been solved. You guys are good. Here's
to all who weighed in with your diagnoses.
John
Dave
Pulled the tensioner arm assembly off, flipped it over and lo and behold...no bushing. Absolutely no sign of a bushing (first pic) 
I can't for the life of me imagine how a bushing would wear or deteriorate to the point where there was no sign of it left in the carrier or on the pivot bolt. So it only makes sense that I didn't put it in on install. Really weird because I saved all of my old stuff so that if I ever second guessed things I could go back. There sit two old bushings, but not a new, 'extra' bushing. I don't get it.
But the lack of bushing explains everything. No shoulder, so the carrier was too far blockward as Dave noted, plus the lack of bushing inside the carrier bore allowed it to turn inward under tension.
The combination of these two conditions would certainly cause the belt to be off track, & sitting forward on the cam gears. The sound that I was hearing must have been the belt beginning to rub against the carrier arm.
Also, sigh of relief: my pump seems fine as do my cam gear bolts.
I'm firing my mechanic.
Second pic: Here's the carrier pulleys showing where the belt shouldn't be tracking.
..but this one's been solved. You guys are good. Here's
to all who weighed in with your diagnoses.AND THE BEER GOES TO:
John
Dave
The roller carrier has move blockward on the pivot bolt. The gap shown in your picture between the pivot brace and the plastic bushing of the carrier arm should not be there. The first thing that comes to mind is that the other plastic bushing on the inner-side of the carrier is missing.
I can't for the life of me imagine how a bushing would wear or deteriorate to the point where there was no sign of it left in the carrier or on the pivot bolt. So it only makes sense that I didn't put it in on install. Really weird because I saved all of my old stuff so that if I ever second guessed things I could go back. There sit two old bushings, but not a new, 'extra' bushing. I don't get it.But the lack of bushing explains everything. No shoulder, so the carrier was too far blockward as Dave noted, plus the lack of bushing inside the carrier bore allowed it to turn inward under tension.
The combination of these two conditions would certainly cause the belt to be off track, & sitting forward on the cam gears. The sound that I was hearing must have been the belt beginning to rub against the carrier arm.
Also, sigh of relief: my pump seems fine as do my cam gear bolts.
I'm firing my mechanic.
Second pic: Here's the carrier pulleys showing where the belt shouldn't be tracking.
05-12-2011, 07:21 PM
#52
Official Bay Area Patriot
Fuse 24 Assassin
Rennlist Member
Fuse 24 Assassin
Rennlist Member
Is that plastic bushing included on the new roller; or is it a separate part to buy? I am trying to gather as much knowledge as I can about this before my very first ever DIY TB/WP service.
05-12-2011, 08:04 PM
#53
Team Owner
the 2 bushes are separate as is the pivot bolt and all of these should be replaced
05-12-2011, 08:31 PM
#54
Rennlist Sponsor
Rennlist
Site Sponsor
Rennlist
Site Sponsor
Sean, I winced when I read this, but it was a very valid suggestion...
..but this one's been solved. You guys are good. Here's to all who weighed in with your diagnoses.
John
Dave
Pulled the tensioner arm assembly off, flipped it over and lo and behold...no bushing. Absolutely no sign of a bushing (first pic) I can't for the life of me imagine how a bushing would wear or deteriorate to the point where there was no sign of it left in the carrier or on the pivot bolt. So it only makes sense that I didn't put it in on install. Really weird because I saved all of my old stuff so that if I ever second guessed things I could go back. There sit two old bushings, but not a new, 'extra' bushing. I don't get it.
But the lack of bushing explains everything. No shoulder, so the carrier was too far blockward as Dave noted, plus the lack of bushing inside the carrier bore allowed it to turn inward under tension.
The combination of these two conditions would certainly cause the belt to be off track, & sitting forward on the cam gears. The sound that I was hearing must have been the belt beginning to rub against the carrier arm.
Also, sigh of relief: my pump seems fine as do my cam gear bolts.
I'm firing my mechanic.
Second pic: Here's the carrier pulleys showing where the belt shouldn't be tracking.
..but this one's been solved. You guys are good. Here's
to all who weighed in with your diagnoses.AND THE BEER GOES TO:
John
Dave
Pulled the tensioner arm assembly off, flipped it over and lo and behold...no bushing. Absolutely no sign of a bushing (first pic)
I can't for the life of me imagine how a bushing would wear or deteriorate to the point where there was no sign of it left in the carrier or on the pivot bolt. So it only makes sense that I didn't put it in on install. Really weird because I saved all of my old stuff so that if I ever second guessed things I could go back. There sit two old bushings, but not a new, 'extra' bushing. I don't get it.But the lack of bushing explains everything. No shoulder, so the carrier was too far blockward as Dave noted, plus the lack of bushing inside the carrier bore allowed it to turn inward under tension.
The combination of these two conditions would certainly cause the belt to be off track, & sitting forward on the cam gears. The sound that I was hearing must have been the belt beginning to rub against the carrier arm.
Also, sigh of relief: my pump seems fine as do my cam gear bolts.
I'm firing my mechanic.
Second pic: Here's the carrier pulleys showing where the belt shouldn't be tracking.
You are a VERY lucky man!! Or maybe it is just karma from being such a great person. Either way....GREAT CATCH!!! That was going to leave a mark that wouldn't buff out!
Hope to see you at SITM, if not, I know I will at the Frenzy (and promise not to talk your ear off this time :-).
__________________
David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
928 Owners Club Co-Founder
Rennlist 928 Forum Main Sponsor
www.928gt.com
928 Specialists on Facebook - 928Specialists
Sharks in the Mountains on Facebook - 928SITM
David Roberts
2010 Jaguar XKR Coupe - 510HP Stock - Liquid Silver Metallic
928 Owners Club Co-Founder
Rennlist 928 Forum Main Sponsor
www.928gt.com
928 Specialists on Facebook - 928Specialists
Sharks in the Mountains on Facebook - 928SITM
05-12-2011, 09:55 PM
#55
Addict
Rennlist Member
Rennlist Member
Join Date: Oct 2003
Location: Gone. On the Open Road
Posts: 16,433
Received 1,605 Likes
on
1,049 Posts
05-12-2011, 10:47 PM
#56
Rennlist Member
Thread Starter
Thanks for all of the feedback & support.
Last edited by JPTL; 05-13-2011 at 12:47 PM.
05-13-2011, 01:49 PM
#57
Rennlist Member
Thread Starter
One last thing:
At $25 apiece is the oem Porsche bushing the only option here?
At $25 apiece is the oem Porsche bushing the only option here?
05-13-2011, 10:06 PM
#58
Addict
Rennlist Member
Rennlist Member
Join Date: Oct 2003
Location: Gone. On the Open Road
Posts: 16,433
Received 1,605 Likes
on
1,049 Posts
No. There is a non-Porsche version. They're tan and not black. I prefer the non-Porsche bushings. The Porsche bushings seem harder - more brittle - than the non-Porsche. And they are a bit cheaper.
05-13-2011, 11:28 PM
#59
Captain Obvious
Super User
Super User
Consider that a bargain. A few years ago I priced them out at the local dealer and they were $75CDN EACH! So I ordered a pair and a pair of hood shocks from one of the 928 vendors for less than $75. Just buy a pair and they will last a long time.
06-01-2011, 09:02 PM
#60
Racer
Join Date: Jul 2009
Location: Byhalia, MS
Posts: 380
Likes: 0
Received 0 Likes
on
0 Posts
I'm getting an intermittent "toothed belt warning". The car is parked until I have time to tackle the job. This thread and the support always available on this forum is absolutely amazing... Cheers to you guys.