jcorenman

A new 85-95 tensioner from Porsche is $1210 list ($880 if you shop around), a good used one is $450 from 928 Int'l (half price sale on now), rebuilt is $350 (plus core) also from 928 Int'l. There's also got to be a lot of good used ones available here for cheap.

I believe that messed-up bores are quite rare (the bimetal washers are located by the pin, not the bore) so refreshing is generally just cleaning and new seals (boot, o-ring, gasket).

Imo000

The OE tensioner doesn't NEED oil to transfer the heat from the engine block. The oil might slightly speed up the heat transfer when the engine is cold started. I think it's there mainly for lubrication.

928phantom

You ever think the high pressure the stock tensioner puts on the belt led to the siezed water pump? not to mention somebody could've over-tensioned it to add even higher pressure by a 1/2 or so turn of the nut somewhere in the cars past, I mean just to have a water pump sieze on any car is like hitting lotto powerball...when my water pump gave me problems it went this, first warning sign was a tiny leak that I couldn't locate and then the water pump started making a squeak as it impeller started to rub against the inside of the pump and that's when I found it, pump was ready to come apart and throw the belt, the warning light never came on.

bureau13

I've always viewed the presence of the belt warning system (that no other car has seen a need to implement, as far as I know) as tacit admission by Porsche that their whole timing belt arrangement was less than optimal. I love the idea behind Ken's use of the Audi tensioner system, but I'll admit...stories of water pumps seizing and breaking the belt with no warning system made me nervous. That's what makes...for me, anyway...the combination of the Porken tensioner and Ed's Guardian water pump so attractive. I still lose the warning system, but I also lose the primary motivation for keeping it...the potential for a seized water pump to break the belt. Perfect!

I do like the idea of re-purposing the tension warning for something else like belt tracking though. Not sure how that would work, but I like the idea.

Someone mentioned that Porken's tensioner was a solution to a problem that didn't exist. I don't view it that way. I view it as an improvement to a system that, in and of itself, has not been known to cause many problems, but does require some due diligence to keep it working properly, and which does protect against some problems that are logical possibilities, even if we can't point to specific examples of those failures. Sorta like Greg's fuel lines....maybe we can't point to specific cars that went up in flames due to the use of rubber hose with barbs and clamps, but there is sound logic behind a belief that it could happen. I've chosen to go with the Porken/Ed/Greg solution suite (ha ha...not sure all those folks want to be part of the same "suite") and your affinity for the rubber hose with clamps is well known... ;-)

MainePorsche

When I told the OP that he should not buy a new tensioner I had no illusion that it wasn't expensive. I made the comment with a question mark for I wanted him to inquire with having the hope it would be inexpensive, then have the loss of facial muscular tension when he was told the price of a new one. I suggested a rebuild of ware components (if possible) if he was staying with the stock unit as he stated earlier. I had to get one from Mark after I did the preemptive TB/WP change when I got my car. The shaft and disc were fused within the cylinder - solvents and a hammer didn't get it out.

Ken if you're still here, can you comment on what phantom said about changing the tensioner. Do you have a recommendation on the interval for this, and also a brief how to.

Thanks,
Craig

Imo000

It doesn't matter what the cause was, the warning system saved my engine. Your belt must have not been loose or else the light would have come on. When the pump siezed the belt will get really hot very fast and will start to stretch, this when the warning system will come on (assuming it's not disabled). If you don't ignore it, it will warn you before the coolant reaches the red to pop the temperature light. You've used your head and the "warning light" went off when you noticed the coolant and then the squeeling. But most people don't.

PorKen

The factory 45K interval is easy to remember. The Audi parts are relatively inexpensive so changing the T/D or all of the parts is good practice.

I believe the Audi parts will last much longer and the water pump is happier so I will probably go at least 60K, myself (if you have looked at the size of the components you know what I mean). My S4 has a Racing belt on it, so that's probably still conservative.


To the OP: If I had to use the factory tensioner, for example if I could not do it myself and had a grouchy mechanic doing the work, I would get a rebuilt from 928 Intl. Be aware that you will be revisiting that mechanic at 1500 miles/2400 kms and possibly every 15K/24K thereafter. And, don't expect a rebuilt or even a new one to be leak free, even with careful installation.

(They leak even when not installed... )

docmirror

A. objection, assuming facts not in evidence. The pressure on belt from the tensioner is something that needs to be set correctly. It's not the tensioner fault if the maintainer doesn't perform the setting right.

B. My tensioner was adjusted perfectly before my belt seized. I checked it before my trip to Marble Falls. No leaks, no noises, but I admit to driving rather spirited when it died. The pump still seized. If not for the belt warning, there would be another 928 broken down for parts.

C. I've seen belts and stock tensioners on 100,000 mile cars before. If the service interval is 45k miles, and one does their diligence with the proper pump and belt, it's work. It - just - works.

Poorly made pumps, and/or poor service actions can't be blamed on the stock tensioner. In fact, given the sad state of service affairs on many 928s, it rather amazing that we don't have more catastrophic failures.

CAMO928S4

Hi,
I didnt imagine this poste would go this far in détails, Thank alot guýs!
After talk with my mecanic at IMAC AUTO in montreal we décides to go with a probable refurbich of the original tensioner but Will see if it stil good to go with that option when its off the car...
Ill keep you posted in january when we do the job.
A big hand of applaus to all

cvhmhjk

Anyone know the highest mileage recorded with a PK?

ROG100

Over 100k with one customer.
About 65K on my GTS
Lots who are on the second or third iteration of the belt.

GlenL

So three tensioners for him? What does the tensioner cost to replace?

hacker-pschorr

The "wear" items are the dampener and the roller and there is some debate over how often those should be replaced (some say never, which is wrong).

These are "off the shelf" parts for an Audi so they will always be available at a reasonable cost.

Personally I would replace both with every belt change. In the Ferrari 355 world (with an almost identical arrangement) most suggest replacing the roller with each belt, the dampener every other......

ROG100

I prefer to change the tensioner when I change the belt - I sell one of the better tensioners for $87 however you can get one of reasonable quality for about $65.

The 100k customer - 2 belts only and did not change the tensioner.

GlenL

Thanks, Guys. I didn't know that the Audi tensioner was considered a "wear" item.

How many people are afraid to post here for fear of jinxing their T-belts?