Problem after changing polyrib-belt on C2

[azeg]

Hia,

perhaps somebody can help me in this case.

With doing my maintenance i also changed the polyrib-belt.

Everything went perfect and if you learn how to use the tensioner the change is done in minutes.

But now i have the following issue.

When accelerating very hard, between 4-5.000 rpm´s the voltage instrument shows a decrease to <11 Volts, and a lot of lights on the dashboard switch on.

Below or above those RPM´s everything is fine.

So i guess that the polyrib-belt get´s slippy and has not enough tension to deal with that torque.

Is there a method of adjusting the tensioner or has it got to be replaced ?

And if so, how is this done ?

Thanks in advance and

regards from Cologne...

[1schoir]

Hia,

perhaps somebody can help me in this case.

With doing my maintenance i also changed the polyrib-belt.

Everything went perfect and if you learn how to use the tensioner the change is done in minutes.

But now i have the following issue.

When accelerating very hard, between 4-5.000 rpm´s the voltage instrument shows a decrease to <11 Volts, and a lot of lights on the dashboard switch on.

Below or above those RPM´s everything is fine.

So i guess that the polyrib-belt get´s slippy and has not enough tension to deal with that torque.

Is there a method of adjusting the tensioner or has it got to be replaced ?

And if so, how is this done ?

Thanks in advance and

regards from Cologne...

azeg:

I'm not sure about whether there is a way to adjust the tensioner. However, since it seems to be relatively minor, why not first try to spray the pulleys and belts with a spray can of "fan belt anti-slip". I don't know what's available over there, but there is one product here made by Permatex that works really well on slipping fan belts.

It takes a few seconds to spray it on and it may solve your problem until you decide whether you want to or can adjust or change the tensioner.

Regards, Maurice.

[azeg]

Hi Maurice,

thanks for the advice.

This is a solution which could work and i looked it up; we have those types of spray here, too.

But this is work on the symptoms and not on the root cause i guess.

Any other hints ?

Regards

André

[1schoir]

Hi Maurice,

thanks for the advice.

This is a solution which could work and i looked it up; we have those types of spray here, too.

But this is work on the symptoms and not on the root cause i guess.

Any other hints ?

Regards

André

Andre:

Is it possible that some (or all) of your pulleys might be glazed from bits of material burnt into them by the old polyrib belt?

If so, you could try cleaning the contact surfaces of the pulley with a stiff brush and some solvent to see if that would help solve the problem.

Maybe someone else here with knowledge about whether the tensioner can be adjusted will pipe in. I was always under the impression that the tensioner is self-adjusting but I'm not 100 % certain.

Regards, Maurice.

[wvicary]

Never use any type of belt dressing as it causes more problems then it fixes. I would recheck that you routed the belt correctly and that it is the correct belt for your engine.

[PAULSPEED]

Sounds like an aternator. Measure the voltage at idle

and at 4,000rpm. Maybe you shifted the alternator

bearings enough to cause this problem.

If the alternator post is hard to get to, then push a new

shirt pin into the cable a little and measure the voltage

to ground.

Paul

[perryinva]

Every can of belt dressing I've ever seen specifically says "NOT for use on sepentine belts". Serp belts lie flat against the pulleys, fan belts lie in the "V" of the pully, it is a temporary solution for a glazed fan belt that slips & squeals. I've learned the hard way, it's cheaper & easier in the long run to change belts. Getting that friggin dressing off is a PITA with degreaser. Sounds like the tensioner is shot, or the alternator or crankshaft pulley is glazed, either will cause the same issue. Depending on how many miles on the tensioner, cranking it back to take tension off (which winds the spring tighter) can often cuase it to be weaker when returned to the same position. I'd guess it's more likely the tensioner.

[azeg]

Hi Paul,

i don´t think it´s the alternator.

It gives constantly 14.4 Volts at any RPM.

Voltage loss is depending on how hard you accelerate.

Belt is new from continental with correct part cross reference number.

Perhaps i got an exemplar that is a few milimeters too long.

I still have the old belt, going to change it, will cross check this first.

But nevertheless, is there a possibility to adjust the tensioner or does it has to be replaced when malfunction ?

Cheers

André

[RFM]

The tensioner is not adjustable and rarely fails.

[1999Porsche911]

Verify that you have the correct belt size and all 6 ribs are on the pullies.

Edited August 4, 2009 by 1999Porsche911

[Mother]

All good replays and not that stock belt is not sufficiant I ended up going with a gatorbelt provides better grip.

[1999Porsche911]

All good replays and not that stock belt is not sufficiant I ended up going with a gatorbelt provides better grip.

I also run Gator for that reason.

[wvicary]

I have installed many belts over the years and would never put a goodyear or dayco belt on anything. What makes you think they grip better??

[perryinva]

Interesting..I used a Dayco on my Dakota ("lifetime" warranty, supposed to be better mileage, less flexing resistance, etc) and it started squealing life heck when cold after 2 years..still looks new, though...put a regular belt from Autozone on it and totally quiet. I'd used Daycos on 2 other cars, never had a problem in the past. I put a new Conti on the 996, from Sunset, and it's quiet, too. What do you know about the Goodyears and Daycos?

Edited August 6, 2009 by perryinva

[azeg]

Update:

Took the time in the morning to change to the old belt (Porsche OEM part).

It was quite cold outside and the issue seemed to be washed away.

But the hoter the engine got and the higher the outside-temperatures raised, the more often the Voltage lowered and i hat my personal light-show of flashing lights at certain RPM´s.

I am personally at the end of my ideas, tried to turn the alternator without belt, runs very smooth and easy without noise.

Don´t know what else to check.

Any ideas before i´m going to give it to the PZ ?

Regards

André

[1999Porsche911]

Update:

Took the time in the morning to change to the old belt (Porsche OEM part).

It was quite cold outside and the issue seemed to be washed away.

But the hoter the engine got and the higher the outside-temperatures raised, the more often the Voltage lowered and i hat my personal light-show of flashing lights at certain RPM´s.

I am personally at the end of my ideas, tried to turn the alternator without belt, runs very smooth and easy without noise.

Don´t know what else to check.

Any ideas before i´m going to give it to the PZ ?

Regards

André

Might be a bad regulator which can easily be replaced.

[azeg]

Voltage regulator is new (this is the reason why i took of the polyrib and exchanged it)...

[1999Porsche911]

Voltage regulator is new (this is the reason why i took of the polyrib and exchanged it)...

Don't assume that just because the regulator is new that it is good or the install is not a problem.