Nick Appleton

I have finally experienced the paranoia that accompanies 964 ownership!

My car has just developed a squealing/chirping noise under load. If I am driving along in 5th or 4th at 30-50mph and then put my foot down, over the top of the usual drivetrain noise that accompanies high gear/low speed acceleration, there is a distinct squealing noise that sounds like a dry waterpump bearing ( no water pump though so can't be that!!) or a squeaking pulley.

If I dip the clutch whilst this is happening, the revs rise (obviously) and the noise is still there, though slightly fainter. If I am rolling along and put the car into neutral, foot off the clutch, and rev the engine the noise rises with the revs, although I have been unable to hear the noise if I am stationary with the car in neutral and blipping the throttle.

I have no warning lights and the car goes, stops and changes gear exactly as it did before.

My local specialist had a quick listen, but said he would need it on the ramp to have a proper look. He's getting married this weekend so I'll let him off!

He mentioned the resonance valve and the clutch release bearing, but discounted the clutch as the noise is still there when you depress the pedal & the car had a brand new clutch fitted in February - 1800 miles ago.

Any ideas, so that I can go back to getting a decent night's sleep??!!

Cheers <img src="confused.gif" border="0">

Adrian

Dear Nick,
A dry rotating device. I would advise you check the engine driven power steering pump, the rear axles for C2 and C4, front axles for the C4 only.
Worse case scenario, rear differential. These noises are very hard to deal with DIY. I recommend you find yourself an experience mechanic and have him drive the 964 or sit as passenger and see what he says. I admit freely that I had to do this years ago on my 944. I could have sworn the noise was from the front, it was the rear axles, both of them. Our mechanic knew instantly what it was when he heard the noise.
I wish I could be of more help but actually tracking down noises over cyberspace is difficult. Electricity is much easier,
Ciao,
Adrian
911C4

Nick Appleton

Thanks for the reply Adrian, I am very conscious of the impossible task you have in trying to diagnose and resolve problems 'remotely'!

I will be putting the car onto my ramps this weekend to have a delve around, I will be passing it to my tame specialist next week all being well. After a brief ride in it, he felt that the noise was fairly central.

I'm puzzled why the noise rises with the revs when rolling out of gear and clutch not depressed, but I cannot replicate this when revving the engine with the car stationary, in neutral?!!

I will investigate and report back

Cheers

<img src="confused.gif" border="0">

Jeff Curtis

Nick, I would place my vote on the heater blower motor, mounted on the left side of the engine -or- your alternator. My alternator is currently making some odd squeeling/chirping noises, like it's going in and out of charge, even does it at idle.

Sounds like bearings to me, I wouldn't think it was the power steering pump, but it could be.

I've adopted the mantra, "don't fix it if it aint broke" with this particular issue - as I can't seem to make ends with it. <img src="confused.gif" border="0">

Irishdriver

Before you spend money check the tension roller on the fan belt. They can sing like a Budgie on his birthday and only require a drop of oil to quieten.

Worth a look first.

Nick Appleton

Jeff, thanks for the reply. It does sound very much like a dry/worn alternator bearing, although I can't work out why it only does it when I rev the engine if the car is moving & not when stationary!

Nick Appleton

Jeff, thanks for the reply. It does sound very much like a dry/worn alternator bearing, although I can't work out why it only does it when I rev the engine if the car is moving & not when stationary!

Apart from that, the car is going, stopping and cornering (let's not forget sounding) better than ever, so i think I will adopt your maxim and try not to worry about something that may not be broken!?!

Cheers

Nick Appleton

Oops, must have been a bit too wild on the keyboard!

Irish driver, I was wondering about that but didn't know whether it was OK to lubricate it with all of that rubber flying around - oil & rubber belts don't usually mix too well, do they?!

I'll give it a go, thanks.

horst

Try spritzing the belts with a spary bottle of water to see if that changes things. Ma be belts. Possibility that when the lid is shut, you have a different air-flow which might stress things differently. It's a reach, I know. Other possibilities which I don't like to contemplate is clutch and/or TO bearing.

Kevin Ross

Nick,

I'm the least technical person around, so this may be way off... when I had my C4, I also noticed a squeal, just like you describe. It turned outto be the Air-Con clutch and after replacing it the noise disappeared. I can't remember if revs made any difference, but turning the aircon off certainly did.

BTW - I noticed oil in the engine bay, sprayed in a circle around the clutch, which is how I diagnosed the problem...

Good Luck!

Nick Appleton

Thanks for all the input guys, I never ceased to be bowled over by response on this Forum.

I will be working my way through your suggestions tonight - will let you know how I get on.

Thanks again
<img src="graemlins/wave.gif" border="0" alt="[byebye]" />

Nick Appleton

Just a quick update!

Irishdriver, you were bang on! I fastened the pulley back away from the belt with a couple of rubber bands and went for a drive..

...result, peace & quiet ( well as quiet as it gets in a 964). Stopped to remove rubber bands & continued on my way, with the squealing once more in my slipstream!

OK, now I'm happy that that is 'all' that it is (!) but how do I fix it?

Is it worth trying to find a s/hand one off a written-off one or can I just buy the wheel/bearing part?! Somehow I think I know the answer to this one...!