rickjaffe

have this odd thing on my 87 S4.

first time I start the car up the belt tensioner light goes on after a couple minutes. when driving or idling.

if I shut then engine off, and restart. go someplace and come back and restart. the light doesn't go on. If it sits for more than a couple hours, same thing. light goes on, then next time I drive it (within a couple hours no light).

had the belt replaced about 8 months ago; haven't had it adjusted since then.

Bill Ball

Rick:

You should know the belt tension is supposed to be checked at around 1500 miles after replacement. The belt comes with a record card that includes this information and the shop should have told you. You are playing with fire driving the car after these warnings. The tension is probably borderline.

Have the tensioner checked for oil fill when the belt tension is checked/adjusted. Also, have the low-tension system wiring to the tensioner arm examined. The wire inside the right edge of the center TB cover has a spade connection to the arm. I've seen these come loose and make intermittent contact.

borland

I would also question that the belt was even installed properly, including the adjustment. The warning light shouldn't come on at any time prior to the second adjustment.

How experienced in 928's is your mechanic?

rickjaffe

supposedly very expereinced, but I'm looking for another guy in houston, any ideas?

rickjaffe

actually the other belt problem I had was that when I floor it, the light would come on too. just stopped doing that and the light stayed off until I had this other problem on start up which just ocurred in the last month or so.

was afraid to bring it back to the same guy.

Bill Ball

That is another bad sign. At best, the belt tension is slightly low. If the shop did not insist you come back for a 1500 mile [actually it's 2000-2500 miles by the book] tension check, something better shops include in the TB job charge so it costs no more to do it, then you need a new shop. Somebody in Houston should give you a recommendation here.

StratfordShark

The belt warning when floored is definitely symptomatic of loose belt.

If you get hold of a Kempf tool then checking and adjusting the tension is something even I managed, and I'm far from a natural 'wrench'! Very clear instructions come with the tool and there are excellent write-ups on some of the owner sites too. I went for the approach where you drain the rad and disconnect hoses (gives you more room to work, and no need to remove the fans).

Sounds like the warning system is doing its job so checking tension is urgent.

Courtshark

I had a similar situation after the retensioning of a replaced belt. It was timely retensioned, yet came loose about 1k miles after the retension. Same deal... it would come on when floored, go off when I shut the car off and not return until I floored it again. Then, it started happening even when I wasn't flooring it. Turned out the belt was in fact loose, despite my suspicion and hope that it was the typical loose/bad contact syndrome. I had it retensioned (for free this time around) and it's been fine ever since. (knock on wood)

Bill Ball

Mike:

IMHO any belt that stretches enough to trigger the warning some time after the 2000-2500 mile check/adjustment should be watched VERY closely. I'd be nervous. Personally I would replace it. They aren't designed to stretch much, and if they do, it should be early on. I don't think a belt that is properly tensioned initially should ever trigger the warning. In your case, we could suppose the initial tension was possibly set on the low end and that it was not changed when checked after 2000-2500 miles. Then it finally went out of spec 1000 miles later. OK, but that is a lot of supposing. The book says to recheck tension and condition at 30K miles and change at 60K, but I'd be watching that belt more closely. One belt on my car tripped the warning at 25K miles. I replaced it right away.

uzzi8865

RICK:
I have heard Koby Motors is the place to go in houston.
maybe somebody in houston could chime in on that.
Mechanic: Paul
8623 Windswept
Houston, TX 77063
(713) 784-8937

rickjaffe

all good and helpful advice. thanks.

Rob Roy

Rick,

I do all my own work (and it shows!), so I am sorry I can't reccommend anyone to you

Garth S

Nothing really odd here - just have its tension measured and adjusted as required!

This is all part of the learning experience. Without specific information, I see no reason to challenge the wrench that did the install: it is shear speculation who did or did not say what .... and what may have been recalled from that conversation.

As to doing the first tension check after install, some brands of belts make the 1500 miles without triggering an alarm - some do not! Each brand appears to bed in ( or stretch) differently .... hardly the fault of the installer, provided initial tension were correctly set.

I have had one popular brand not make 500 miles before triggering an alarm: another of the same made 1200 miles. Once retensioned, they have been silent for the last ~ 4 years. Maybe the warning light shouldn't have come on prior to the first adjustment interval .... let alone the second one - but it happens; however, it could be mere inexperience. On the other extreme, the brands installed on my cars have required 0 adjustment in 4.5 and 3.5 years respectively ..... yes, they were checked.

If one does not do their own adjustments, do the wrench a favour and leave the car long enough so it can be done on a cold engine: the tensioner is a 'detensioner' .... designed to relieve tension on a hot engine, and it is far from a perfect device: ergo - for best results, set tension cold. I've done the last 3 'hot' for guys who had to drive some distance to get here .... neither the most fun nor precise way to do it, so you take your best shot.

rickjaffe

had koby readjust the belt. they did it quickly (dropped it off friday, picked it up monday) for a reasonable fee $189, two hours. The problem seems to be fixed. I'll use them again when the need arises. thanks

Bill Ball

Well, I hope this is all's well that ends well. If they never told you to come back at 2000 miles for a tension check, I would still avoid them in the future. Two hours may be book, but is is an hour longer than it should take.