Squeak not from the accessory poly belt?

[dammad]

My 996 Cab Tip has developed a chirping squeak. It occurs while standing still at low RPMs and particularly on light low end acceleration. Initially I thought it was the poly rib belt slipping (which I know it shouldn't be due to the tensioner and the belt being pretty new). So I figured I'd locate the noise by removing the airbox, starting the engine and using a short length of plastic tubing to localize the area of the sound.

I expected to be coming from one of the pulleys but it wasn't. The sound appears to originate from the left (drivers) side of the engine next to the coolant tank. It can also be heard easily from the rear drivers wheel well. I didn't think there was much back there except the engine itself?

Any ideas? That area seems very inaccessible so I hope its not a PITA to fix.

[wvicary]

Loose spark plug?

[dammad]

Hmmm.. I hadn't thought of that.. That is an interesting idea.. What torque are the plugs supposed to be?

[logray]

19 ft lbs + 3.5 ft lbs on reinstall.

Edited January 30, 2012 by logray

[fpb111]

AOS can make squeak when starting to fail, often turns to howl as it gets worse.

[L986]

AOS can make squeak when starting to fail, often turns to howl as it gets worse.

+1

I know it can sound quite strange, but mine (996 C2 MY98) had the same symptoms and replacing the AOS did the trick.