2000 STS making weird rattle sounds by the water pump area & water pump belt housing

MaupinMan16 · #1 (**permalink**) 01-21-09, 06:20 PM

My friends 2001 Cadillac Seville STS with 61,000 miles is making a noise from the water pump belt or water pump area which sounds kind of like a rattle sound when idle. I have used some belt dressing thinking that is could of need some lubricating but that did not solve the issue. Everything seems to be bolted down in the area and the belt is secure. I am wondering what type of sound a water pump would make when it is going out. This noise hads nothing to do with any sound associated with knocking or ticking ect. because it is not coming from the engine area where those types of sounds would come from. I do not abuse my vehicle or do Wide Open Throttle like I have heard in other forums. Can anyone with some kind advice let me know what this could possible be. Thanks

**Ranger** · #2 (**permalink**) 01-21-09, 09:56 PM

WOT is good for it. Do it.

It's more likely the tensioner bearing. Use a 1/4" drive breaker bar and put the drive lug in the square hole in the back side. Use it a lever to release the tension and see if the pulley is wobbly or noisy.

Oh yeah, no belt dressing.

xPosTech · #3 (**permalink**) 01-21-09, 09:58 PM

A rattle as you describe sounds suspiciously like a tensioner bearing. But it's on the other end of the engine.

A mechanic's stethoscope would help isolate the noise to a specific engine accessory mount. They are cheap and sometimes indispensable in locating aggravating noises.

Ted

Edit: Hmm . . . the tensioner I mentioned is on the other end but Ranger is right. Water pump tensioner behind the shield. Well shoot . . .

submariner409 · #4 (**permalink**) 01-21-09, 10:04 PM

"My friends' 2001......" and "I do not abuse........."

Is this your problem or that of a friend ? Why the disclaimer for "your" car ?

I smell a rat.

(There are two tensioners on a FWD Northstar: One for the main 6-rib accessory drive belt and one for the water pump 3-rib belt.)

retcoa · #5 (**permalink**) 09-01-09, 03:01 PM

Are we talking on the driver side or passenger side. I have a rattle noise coming from the driver side by a pully belt up near the radiator. it sounds like bearings. Can you tell me what that pully connects to and what it is for. Where is the alternator located and the water pump. I also have a leak somewhere but it is not oil. More like coolant and it is under the front of the engine area. thanks

**Ranger** · #6 (**permalink**) 09-01-09, 05:58 PM

The small belt on the drivers side is for the water pump. Remove the black belt shroud and you'll see the tensioner pulley. Likely the cause of the bearing noise. Not sure what pulley you are talking about. There is a drive pulley on the intake cam. Atensioner pulley and of coarse the water pump pulley.

The alternator is on the other end (front) of the engine on the bottom.

submariner409 · #7 (**permalink**) 09-01-09, 06:00 PM

The "front" serpentine 6-rib belt, driven by the crankshaft/balancer pulley, runs the power steering, a/c compressor, alternator and turns around a spring arm tensioner/pulley and also an idler pulley.

The setup on the driver's side ("rear") of the engine is a large 3-rib pulley, driven from a snout on the end of the "left" intake camshaft, which goes around a tensioner/pulley arrangement and the water pump pulley. If you hear ANY noise from down in there you're in immediate danger of losing the water pump and/or the tensioner pulley bearing. Many threads here and in Northstar Performance concerning water pumps, tensioners, and belts.

You need to find the rattle at or near the water pump NOW !

With a leak under the front (radiator side) of the engine I suspect a water pump shaft/seal. Very, very, very different from any water pump you have ever changed before............

MaupinMan16 · #8 (**permalink**) 09-07-09, 02:38 PM

Yeah i had this problem fixed months ago and what i was is i needed a new water pump and a tensioner, the tensioner though was the part that needed to be replaced not the water pump but i did it anyway just to be safe. I also needed a water pump gasket and a water pump belt.

After those services where performed it was all fixed and working great with out any noise and it doesnt sound like your motor shot.....hahah

Anyway it was around $230.00 dollars for the enitre fix although it is a pain to remove a bunch of stuff to get to the pump and tensioner which will be a three hour job or so for the do it your selfer.

Thanks

CadillacSTS2003 · #9 (**permalink**) 09-07-09, 07:19 PM

tensior
beyond a doubt

chazglenn3 · #10 (**permalink**) 09-08-09, 09:36 PM

I have a rattle from the engine compartment, but it seems to be lower than the water pump belt and tensioner. In fact, I can't figure out what the noise is...may be from the transmission...does the water pump tensioner noise travel? The noise is louder at idle...can't hear it above idle.

**Ranger** · #11 (**permalink**) 09-08-09, 10:36 PM

Noise can be deceiving. Snoop around with a stethoscope. You'll be amazed at what it can pick up and how easy it is to pin point a noise.

MaupinMan16 · #12 (**permalink**) 09-09-09, 12:21 AM

it more likely the water pump bearing itself that has gone bad.......mine did the same thing very loud at idle but once you move the throttle it goes away or it is barley as noticeable.

I doubt it is a transmission problem

See if there are any codes in the system

chazglenn3 · #13 (**permalink**) 09-11-09, 12:12 AM

Any way to check the water pump bearing like you can check the tensioner?

chubbyranger · #14 (**permalink**) 09-11-09, 03:17 AM

Quote:

Originally Posted by chazglenn3

Any way to check the water pump bearing like you can check the tensioner?

Remove the belt, wiggle the pulley. Any play = junk bearing. Mine also started a weep leak when it went bad. It was hard to find, especially since it was my first N* problem when I got the car so step 1 was figuring out the water pump setup. I could smell the coolant leak more than see it. An hour with a flashlight under the car and finally tracked it to the water pump housing.

badrhino · #15 (**permalink**) 09-11-09, 04:26 PM

I have a rattling noise coming from the engine compartment that you can actually here in the car. But it only happens when the AC is on and at idle. Does anyone else have this problem?

I have looked under the hood for the cause but I just can't figure it out.