Whistle sound increase with the engine rpm.

Check any vacuum line near there and the intake air hoses and plastic parts for a break or leak. A small opening in either one will cause a whistle that varies with RPM.

My neighbour has a whistle in his 1980 350 Suburban that helps us hear him coming way before you can see him. My guess (and that is all it is) would be the water pump.

-- Regards Gordie

Water pump runs off of the "fan belt" as he calls it, properly referred to as the serpentine belt. If it's making noise with the belt OFF, the water pump isn't spinning, hence it couldn't be the water pump making the noise.

Doc

When does it go from fan belt to serpentine?

~KJ~

AFAIK, 88' was the transition year from v-belts to the serpentine system on full-size trucks. The older style trucks usually ran the water pump and PS off one belt, alternator and water pump off the other (dual groove pulley on the water pump, 2 belts).

Doc

AFAIK, 88' was the transition year from v-belts to the serpentine system on full-size trucks. The older style trucks usually ran the water pump and PS off one belt, alternator and water pump off the other (dual groove pulley on the water pump, 2 belts).

Doc

don't forget the cheesy double pulley on the PS pump that carried the belt for the AC in the second groove

Who the f*ck thought up that abortion

Bwahahaha! That was late 70's and early 80's IIRC?

Doc

Guess that answers it. Kind of thought of the answer after I posted. I meant more like "how could I look at something and get the right name?"

My thought is, once it turns back on it's self, it's now a serpentine belt.

I think your right about the year, a friend of mine had an 87' blazer with fan belts, and I have an 88' S10 with serpentine.

~KJ~

on the Burbs, at least, 88 was a transition year.............a mix of V and Serpentine

plus some had regular water pumps and some had reverse rotation, bepending on the belt arrangements

If it has ONE belt that runs everything, it's a serpentine belt. If it has more than one belt, they're V-belts.

Doc

Maybe 87' was the transition year for belts the FS trucks then, as the burbs were always a year or so behind the trucks.

Doc

A V-belt looks like a Vee.

My wife's 86 fs truck has a V-belt for the power steering and a multi-vee (often called poly-vee) belt for the alternator. It became known as surpentine because of the path the belt takes. The serpentine belt uses a belt-breaker adjustment pulley instead of the old fashioned way of moving the alternator or power steering pump to adjust the belt.

Anyway, I thought it might be the water pump on my neighbour's truck but he swears it is a leak in the exhaust manifold. You would think the noise you might hear wouldn't be a whistle if that were the case. Must be catching because my wife's truck has a faint whistle now too.

Maybe a vacuum leak?

-- Regards Gordie