CAMO928S4

My 1988 S4 is going in à major service at my Porsche mecanic in Montreal. It has 75000km and need's à timing belt service since the Warning light came on ...

If needed, my mecanic tell me to go with the standard Porsche tensioner to make sur the engine works as it was ment to and réduce risk of à timing fault ($$$$) and garanty the work done.

What sings sould i look for to know if the tensioner has to be replaced or rebuîlt or reinstalled ?

Since the Porsche tensioner cost 1500$ to replace and the porken tensioner with kit cost 500$:
A) how would you consider the risk of an engine fail betwen the Porsche tensioner and the Porken tensioner ?
B) is the porken tensioner garanted if there's à timing fail and engine break ?
C) if so how does the waranty apply to a 1988 car and what is covered ?
D) sould the air smog pump be deleted and why ?
E) the water pump is shurly to be replaced... What pump sould be used if i get the porken tensioner for my 1988 S4 with auto trany and would it cost les ?

For info, here is the rest of what to do on my car :
- new rebuilt sterling rack (leaking boot)
- valve cover gaskets
- new boge standard shocks on all 4
- new rear brakes (just pas or disc to ?) to solve the anoying noise ?!?
- alignement after 100km
- vérifier and correct the gas lekage from top of the gas tank (any suggestion ?!?)
- vérifier and solve the grinding noise heared when motor is runing and seems to be at the start of the tork tube ???

Please let me know what SHOULD be replaced at the same Time as all this work is beeing done. I PLAN ON KEEPING THE CAR AT LEAST 10yrs ... There is nothing like this shark !!!

MainePorsche

Oh Boy.. here we go again...

I've always had the stock tensioner, and it has always done its job. What I didn't like about it is that no matter how meticulous I was rebuilding it, and installing it, it was always a little shy on oil within the housing. After years of reading here on its testing and function, I am going to a PKT on the next change over. This will be coupled with a Gates Racing (now Long Life) Belt and a Guardian water pump. There was a recent thread titled 'cheap water pumps' or something like that, where there was some very good discussion on matters that you may find of interest.

CAMO928S4

Hi maineporsche,
I appreciate your info and when on to reading on the post of the cheap water pumps and made my choie for that issue.
How do you rate the risk of installing the pk tensioner vs the original tensioner ?
Thanks

hacker-pschorr

Anyone know the highest mileage recorded with a PK?

MainePorsche

Steve,
I haven't installed it yet, but it doesn't look to bad.

https://rennlist.com/forums/928-foru...t-edition.html

Randy V

https://rennlist.com/forums/928-foru...l#post12835336

jcorenman

Porken told me that ours, at 75K, was the highest. That was just before I pulled it out.

jcorenman

Camo928s4,

How many km's on the car? When was the timing belt last replaced?

For the Porsche tensioner, replacement is very unusual. The typical cost to refresh the tensioner (rubber boot, o-ring, gasket, bushings for tensioner arm) is maybe $150. If the tension pulley needs to be replaced then another $150 maybe.

The advantage of the PKT is that it is self-adjusting and does not need adjustment. Hundreds have been sold, with two failures reported here. The factory alarm circuit is disabled.

Many thousands factory tensioners were sold of course (one per car), maybe a billion miles, and some failures reported also-- worn parts, bent shoulder-bolts (pre-87), etc.

Cam sprockets also wear with either tensioner, replacement is needed sometime around 100K miles.

Water pump failures can cause a belt failure with either design. In some cases the factory alarm will provide a warning, but not always.

Opinions are divided, and arguments often result. This thread will likely not go well, but we can hope. The designer of the PKT and Roger who sells it both recommend it, this is natural. And it is also hard to argue that the factory tensioner, designed for this specific job, is not perfectly suited for it.

For a while I believe we had the most miles on a PKT, 75K miles from early 2009 until late 2013. After learning of the failures and doing a careful design review, we changed back to the factory tensioners. (My background is engineering, nearly 50 years).

If you do your own work then learn everything you can, and ask yourself what is important. Are you comfortable with no belt-tension alarm? Is the convenience of no adjustment a priority? How often is aftermarket better than stock?

If you have a mechanic work on the car, and if they understand 928's, then their opinion is probably the most important factor. It is almost always a bad idea to ask a professional mechanic to do something that they are not familiar or comfortable with. But if they believe that a tensioner always needs replacement, then they do not understand 928's.

Bmw635

My wife's old RX300 use the same tensioner at 120k miles as the Pkt so I used it in my 928 instead of the Oe.

OTR18WHEELER

Can I play?
A, neither tensioner would cause or prevent a fail, but the after market one will not give a tension warning light.
B, no
C, N/A
D, yes, lessening a fail point while increasing HP.
E, The porkentensioner will most likely outlive whichever water pump you choose.
...I probably drive my car harder than most beauty queens here as a any day driver, still using the OEM tensioner, rebuilt with the TB/WP change a couple years ago.
Stock '85, still original caps, rotors, wires, MAF, ...96K miles.
Kinda twerky on launch.

m750rider

Just the thoughts of a 40+ year engineer (not mechanical though), so take them as not more than my personal opinion. I am not an engine or machine designer, but have had experience with a wide range of cars in my time.

The Porken Tensioner is a nice solution to a problem that doesn't really exist.

The OEM tensioner system works fine, I haven't found in my searching anywhere that having it leads to belt failures. It is not difficult to maintain. It allows for the belt tension warning system to remain in service, which I also like

I've owned an Audi and I am familiar with the other tensioning system. It's a good one. If you think that the belt on a 928 needs additional/enhanced tensioning, go for the PKT.

I just don't think it does, the original design works well. Rebuild the tensioner, use a Porsche water pump, you're good to go.

GlenL

I'm in a similar demographic and have the same opinion: the original tensioner is fine.

Failures in the belt system are often due to improper maintenance. Some of it willfully bad by hack mechanics.

The tensioners themselves never wear out. It's the bearings in the pulleys/idlers and rubber boot that need replacing.

Get a mechanics who actually knows the car and isn't just "I've-done-it-all" ready. Use the stock tensioner.

CAMO928S4

Ok, all this info is very useful...

CAMO928S4

Ok, all this info is very useful...
Since i'm not personnaly working on the car and my Mecanic recomended to go with stock tensionner, i'l go with kit for stock tensioner and keeping evrything OEM.

Please suggest were to buy the kit to refresh porsche tensionner and info on how to do that job.

How would you rate the Guardian ou GEBA water pumps VS The original Porsche water pump ?

Thanks guy's ... All this is get tong me somewere, buy i stil don't have any idea how Mush this major service will cost ? (Would you have an estimation in parts an labor ?!?)

CAMO928S4

My Sharks is a 1988 s4 has 75000km and no record of any timing belt change buy the Mecanic Mase a t belt check up last year (4000km ago) and all was fine...
Since then the warninh light cam on ONCE... Never seem it again!
Buy all you owner's firm'y recommanded that de t belt service and water pump be done to prévent any important motor fails
Thanks for rhe good info everyone.
I would like to have other information on the other work my car needs to be a good and secur driver's car (see first post), Thanks��