996 Turbo engine noise

[74driver]

Had this on going engine noise at idle only. Brought it to the main dealer had it looked at under warranty a few times. They said it was one of the drive belts which is exactly what it sounds like. Like a squealing noise. Extremely irritating & sounds absolutely ste!
They replaced a few of them but said that the issue is moisture that causes the squeaking/squealing & that its an issue with the 996.
Surely this can be sorted, its a Porsche ffs?
Has anyone else had similar issues or know or a fix?

Cheers!

[Big_Dog]

WD40 is your friend with noisy belts. Not too much though.

[davek_964]

Is it only when cold, and especially when wet?

Mine has done it for the last couple of years. This winter it actually sounds slightly worse - almost like the pulley is about to fall off! (I've checked - it's not).

It does sound a bit rubbish.

[m996tt]

What have they replaced? There is only one drive belt and can be replaced reasonably easily,
It could also be one of the rollers or the alternator bearings. You could
remove the drive belt and manually test the rollers to see if one is knackered.

[Rockster]

74driver said:

Had this on going engine noise at idle only. Brought it to the main dealer had it looked at under warranty a few times. They said it was one of the drive belts which is exactly what it sounds like. Like a squealing noise. Extremely irritating & sounds absolutely ste!
They replaced a few of them but said that the issue is moisture that causes the squeaking/squealing & that its an issue with the 996.
Surely this can be sorted, its a Porsche ffs?
Has anyone else had similar issues or know or a fix?

Cheers!

There is a problem and it ain't moisture.

My 996 Turbo belt chirps a few times when I start the cold engine after leaving the car parked out in the rain. But the noise is like I said a chirp, short and not very loud.

The chirps can occur a few moments after starting.

After one particularly wet storm when I first started the engine the voltage reading was low. it was clear the alternator wasn't spinning and thus not generating electrical power. This went on long enough I thought maybe there was something wrong rather than the belt just being wet but I gently raised to around 1500 the rpms a couple of times and then heard the chirps and a moment later the voltage level climbed up to nearly 14 volts. Things were fine after that. Surprisingly the engine did not misfire this time, but it has once in the past under similar circumstances.

But no way should the belt squeal.

The dealer should id the source of this squeal and fix it.

The belt is bad: check for sharp edges which means the belt is not tracking properly which can be a sign of an accessory drive worn out. Water pump can cause this. Check the belt for missing sections of its small v's. Cross cracks are ok but no v should have missing material. A roller bearing can be bad, dragging and the belt squealing as it slips over this roller. The tensioner can be bad which means the belt is not under the proper tension and thus slips. There can be a fluid leak which is contaminating the belt/pulleys.

BTW under no circumstances should you use WD 40 or any other "belt" lube. These belts are designed to work quietly, efficiently, reliably, with no application of anything.

[74driver]

No its not just when wet & even after a 90min journey its still squeaking. Pretty sure the drive belt was changed & it has a new alternator so can't be the bearings. Its a relatively new thing(last 2 yrs) so its something that has developed over time.
Had a squeaky fan belt years ago on my Renault 21 Turbo & indeed WD40 did do the trick, but don't think its the ideal solution!

[NBTBRV8]

I had a strange noise appear in mine after I changed the power steering pump. What it turned out to be was during the change some Pentoshin got on to either the belt or a roller and when it was put back together the belt transferred it to the other rollers. The Pentoshin became sticky and when idling you could hear the belt unsticking from the roller as it came off it, but you couldn't hear it above about 1500rpm.

twist the air box out of the way, but keep it all connected and get a bottle of spray water and when idling spray each roller and see if the noise goes away for a second or two. Short of that you could unhook the belt and spin each roller and feel the surface of each. At this point you can also give the surfaces a clean. However if it is something on a roller I would probably change your belt again as it will have soaked in to the belt and you won't get it out now.