davek9

New owner had an 85/86 in the past and loves 928's, picked this '88 Auto one up for ~ $6k, much differed maintenance and I think he knew it.

So he just got the car and was driving near home and the T Belt Light went off, Shocked!!! by this, he pulled over and turned off the ignition, and called a Flat bed.

Once I started removing the layers I spotted the WP pulley through the center belt cover as he looked on, "that's not good I said.." and we proceeded.

Before I remove the center belt cover I turned the engine by hand to 0 TDC and using the 32vlvr I checked cam alignment and it was w/in 2 deg per side, (gear notches were off at least a tooth but that is typical).

So I move the Crank to 45 BTC, removed the center cover and when I removed the belt tension the WP pulley fell off!
The WP shaft seems good, no play and the block looks great too.

I looked at John and said time to buy a Lotto Ticket

Two things come to mind w/ this one.

1. 928's are inexpensive to purchase with years of deferred maintenance on them.

2. We need to activate the Belt Warning Light w/ the Ken-Tensioner (Audi unit) solution (this car had the stock tensioner IMHO it was over tightened for sale).

Dave

Mrmerlin

thats a lucky save,

glad someone knew what they were doing

SeanR

Good save, too many won't pull over when the light comes on. It's still going to be an expensive fix due to the cam gears being trashed.

davek9

Yep, quick thinking on his part and having prior knowledge about 32v's saved him the additional expense of a Valve job!
Haven't removed the gears yet to get a straight edge on them, possible re-coat, Oil pump is not steel so that on is getting replaced.

I know of at least two owners who tried to make it home after the light came on and didn't promptly turn off the car and that didn't work out so well

joejoe

I have the lower shield with the oil pump gear about half way out. It is a sick feeling to see, but great relief when found that all is 'well' (relatively speaking) On mine the nut had loosened and gear rode up the shaft and through the shield. Gear was running about 25 degree.

Imo000

Well done. This is exactly what every 32V owner, that still has a functioning warning system should do. I saved my engine by shutting it down when the light came on (failed WP bearing).

James Bailey

Sadly more than one owner has had their t-belt warning light disabled by a mechanic who simply grounded the wire so the warning never comes on again rather than fix a problem.....

WallyP

(Temporary Thread HiJack On...)

James,

Isn't it about time to get a part as the Easter Bunny and change your photo costume?

(Temporary Thread HiJack Off.)

Chalkboss

Might be a dumb question but I'll take my licks. If the warning has been grounded would the light still come on when the key is turned to the acc position? Or, if you see the light go on at acc then off at run position then you can assume it was not grounded?

BC

Most of the time they are disabled. And the reason is it goes off ALL the time on these cars for no apparent reason. I replaced the belt on two separate S4s with new WP, nearly new cam gears, tensioner rebuild with new roller bearing sets, etc.

Light goes off.

Its a double edged sword. This is one of the reasons people never really liked these cars. They heard about the belt, and the tinkering and the warnings and then mechanics didn't know what to do. So now we have 80,000 dollar cars selling for 6k when a comparable car from that period is selling for much higher dollars.

To make the light stay off, the belt gets over tightened, which breaks the pulleys and water pumps.

kmascotto

o.k. i've read a lot about the idea of the Audi Tensioner unit solution. Now correct me if im wrong....these units are self contained hydraulic units...is that accurate? I'm an old 911 guy and my 71 911 had self contained hydraulic units (2)...Porsche realized in 1984 these self contained hydraulic units were the Achilles heal of all the 911's to that point. The unit would lose hydraulic pressure (no warning at all) when the internal seal let go (and they did)...and the 911 being just like the 928 32v...pistons hit the valves...Porsche changed this system to pressure feed tensioners to solve this issue. It seems strange to put this system back on cars.

Question: Did Audi designed this tensioner for zero clearance motors?

Thanks

BC

The Audi design is very different than what you are describing. There is little risk of a seal letting go.

That is very much like Porsche and the 911 designers to double down on the hydraulic pressure of the oil system.

kmascotto

May I ask, how is it different?

kmascotto

Here is a great video of the 911 tensioner history.

PorKen

Belt vs. chain: lower tension

Aluminum vs. cast iron body: less friction

External vs. internal mounting: air cooled vs. oil heated


Native engine is AUDI 2.8L 30-valve, with a heavier belt (wider and thicker) vs. 928 belt.



A number of 928 installations have exceeded 50K miles with this setup.