Joe '87 S4

My timing belt light came on for the first time in 10 years about 5 months ago. Stopped driving immediately, had it towed to the shop. (The belt/wp pump - whole timing belt system was changed about 2 years ago and the belt was retensioned after 1,500 miles. Less than 10,000 miles driven since the belt change) The shop checked the tension this time, said everything looked good: belt/tensioner/etc and said the tension was within spec. I did have a problem with the light 10 years ago when I first got the car with the light not working at all but had it fixed.
The other day, just driving at 20 mph the belt light came on again. No load on it. At other times, passing someone on the freeway, downshifting, etc., I get no light. I know you're going to say I'm taking a chance driving it with the light coming on at times but I really don't think it's a problem with the tension, I think it's an electrical problem. Anyone have that type of problem?

the flyin' scotsman

The tensioner light system in the OEM system is a break ground set up. It can be made to work quite reliably if everything is set correctly. My suggestion would be to befriend a local Rennlister who has very good knowledge to give the system a look see.

An alternate strategy is to upgrade to the Porkensioner system.....many many folks now use this new and improved system which is troublefree with zero maintenance.

blown 87

Ignore the warning light at your own risk.

Stromius

Buy yourself the Kempf tool and learn how to check and retighten your belt before you drive it again. Not a good sign if the light comes on but can be an electrical issue and easy enough to take off the TB cover on the passenger side to see. (Distributor cap, rotor and 3? 10mm bolts is all).

Do some searching on this forum on how. There are plenty of threads with the how-to and good pics. Many of us have ditched the old tensioner in favor of the Porkentensioner, myself included.


Post back what you find...good luck.

rgs944

I would also suggest buying the tension tool. I did not here any mention of you cleaning any contacts. I would get the tool, take the passenger cover off and inspect and clean all wiring and connections. That of course after you check the tension one more time. Did they check to see if the tensioner had oil in it at the shop? How much do you trust the guy at the shop?

safulop

The Porkensioner is great, but it doesn't guarantee anything about the timing belt warning light. Mine comes on at high RPMs like old faithful. There can certainly be electrical issues that cause it to go off.

-Sean

Imo000

Sure it does. It gaurantees that the light will NEVER come on.

Bill Ball

May be something loose in the wiring connections. I saw another local car that had the light going off periodically. Tension was good to high. Found the spade connector on the tensioner arm was loose.

If you have some time, I'd be happy to take a look at it. Maybe we'll find something.

tilac999

I thought the Porkensioner disabled the timing belt light. I'd love to get one but I hate to give up the light.

rexpontius

Just get the Porkensioner, it is a much better solution compared to the original tensioner of which the design has not really changed since its introduction in the late 70-ies AFAIK.

Landseer

The tensioner warning system and stock tensioner arrangement should be treated as a single system by a 928-knowledgeable shop. The shop should not release the car for use unless the warning system is working properly. There is a procedure in the technical literature for tracing the electrical circuit. We know that the omission of the obscure washer from the contact end of the tensioner arm can cause premature warning, ie, a mechanical cause for the electrical warning that can cause the problem while the belt still tracks well. Belt choice also may be an issue. I've had to retighten the Conti belts more times than expected due to stretch. The combination effects can cause the light.

BTW, at what interval are you guys with converted systems planning to change the Audi tensioner module?

rexpontius

I think the audi tensioner is designed to last much longer, but I am going to replace it every 60.000 kms or 4 years, whichever comes first (pretty sure it will be the latter :-))

Cheers

Imo000

Keep in mind that the Audi tensioner is desinged to last X amount of Kms on an Audi and not on a 928.

I LOVE the factory tensioner warning. It saved my a$$, big time, last summer.

the flyin' scotsman

It DOES.....absolutely correct.

Sean....if you have a Porkensioner installed and the tbelt light comes on at high rpms theres other issues with your car as well as the fuse/relay panel (other thread).

My first response to the OP was to encourage him to seek out an experienced Rennlister rather than take it back to a $$$$ shop and presto Bill offers his services as I would have done if nearer.

Bottom line......get this issue fixed asap by someone who knows what they are doing.....good luck

ROG100

My thought on the PKensioner change interval.
In theory the system should be good for 100k. In reality we do not know as yet.
As we have to go in and change the timing belt at the normal interval I would recomend changing the tensioner but not the roller and lever. Roller will need to be checked for bearing wear of course.
The tensioner is a cheap item.