Belt whine fix

[Stephen03]

Just something worth mentioning. I've had pretty loud belt whine since I changed my belts and I just recently replaced them again. It sounded just as loud as before so I really loosened the balance belt... Didn't make any difference. What it ended up being is I had to adjust the balance belt idler up so there was a 2-3 mm gap at the bottom. That got rid of it. Now there is almost no whine while cold. Something worth trying if you are sick of waiting for the engine to warm up.

[Grandad#3]

Hi Stephen, Were you using Gates Belts? Remember to readjust the tension on the Balance Shaft Belt at or before 1,500 miles.

Cheers,
Larry

[v2rocket_aka944]

From the sound of it your idler was too close to the lower balance belt gear.
There should be tons of clearance and the idler should be almost touching the long span of belt from tensioner to upper B-shaft.

[boeing 717]

Can you give me more info on this. My 968 had all new belts and rollers recently and the belt whine is crazy loud. My car sounds like I'm driving an electric motor. Below 2800 rpm I can't even hear the engine only belt whine.

[v2rocket_aka944]

The timing belt on the 968 is not adjustable for tension - there is an automatic hydraulic tensioner for that.

The balance belt is still 'manual' like the 944 and most people set (incorrectly) them about as tight as the timing belt when it should be much looser. The balance shaft belt runs very loose actually...too tight and it whines like crazy. You should be able to grab the long span of the belt between the upper balance shaft gear and the lower tensioner and twist it between your thumb and finger 180 degrees on itself and no more.

[dgcantrell]

Yeah, the first time I ever did the belts on mine, I got the balance shaft belt too tight. Whined pretty loudly.. Loosen it up to where you can twist it about 100-120 degrees by hand.

[boeing 717]

Is it a big job to get that cover off for adjustment?

[djnolan]

I use a stethoscope to listen to the rollers for Telltale whine which means something's to tight water pump roller and your two tension rollers on both belts

[djnolan]

You also want to be tensioning the balance shaft belt tensioner in the clockwise Direction and not counterclockwise

[v2rocket_aka944]

Boeing - no, there are 10 or 11 10mm head bolts (11 bolts for a 944 but I think the 968 cover was revised a little) that are pretty easily accessible but you'll need to jack the car to get to the bottom ones.

[boeing 717]

Ok thanks I'll get to it one of these days.