Question about waterpump

hey guys,

sorry to start so many new threads.

this question is for my 91 XJ 4.0 , starting this morning there has been a awkward noise coming from the front of the engine. i've been looking closely to try and determine what it is, but i'm stumped. i'm narrowing it down to either the waterpump/waterpump pulley or the crank/crank pulley. i'm really hoping that it's just the waterpump. i can't really describe the sound... is there any way to test the water pump and or the pulley?

btw, oil pressure is good, and i'm not overheating i'm running right under 210.

If the car overheats...it's probably the water pump.

does your power steering feel ok?

Does your a/c work?

*most likely a bad idler pulley if it has not overheated and you don't notice it driving.

What type of awkward noise? Pull the belt off and start it up... if the noise went away then spin each pulley by hand and listen for the noise or feel for a roughness when you spin them.

If it is just squeeling, the belt is probably too loose. Safest advice is to get the Krikit II belt tension gage and set the tension properly. If it's not a squeeling sound, do like MrJCRod says.

All good advice posted above.

For locating sounds you need a way to isolate the area. Use a 3' piece of vinyl tubing, about 1/2" ID (all measurements approximate). Stick one end of the tube in your ear. Carefully move the other end of the tube around the running engine--while keeping vital parts of your anatomy and your clothing clear of the moving components--the tube will help you quickly locate the source of the sound.

if you think it's the water pump, or water pump pulley, pull the belt and feel for play/wobble. if it's real bad, you can probably see it wobble with the engine running. (before pulling the belt, dont run the motor without a serpentine belt OBVIOUSLY)

waterpumps go out fast, especially if you install autozone or similar pumps... i can change a waterpump in an hour ive done soo many. PULL EVERYTHING IN YOUR WAY, first!

your gonna need a strap wrench to remove the pulley.

ive had water pump's wobble, due to a botched pulley re-routing (left out a single washer on my high mount alternator) it was visible with the motor running, made a terrible sound/vibration but it did NOT cause me to overheat....

If the belt is tight, try loosening the bolts on the water pump pulley with it still on and you may not need the strap wrench. Just crack them loose a little, even if you're not sure it's the pump, and you can always tighten them up again when you're done testing. But if the pump is bad you might even be able to feel the play with the belt tight if you just yank on it.

All the times I've had an XJ water pump go, it has neither squealed nor leaked, but just started rattling. The seals on these pumps are surprisingly forgiving, and when the bearing goes, the impeller hits the body of the pump and prevents it from wobbling beyond a certain angle, but it gets pretty ugly in there. I ran my 95 for way too long with a worn-out pump, because the noise was so much in the same pitch as its piston slap that it blended in. Same with my stepson's 93. He pulled into the driveway and I thought "hmm, it's sounding a bit extra slappy today," and he said, "yeah, I thought it was getting a bit worse," and then the light bulb lit.

Matthew Currie said:

All the times I've had an XJ water pump go, it has neither squealed nor leaked, but just started rattling. The seals on these pumps are surprisingly forgiving, and when the bearing goes, the impeller hits the body of the pump and prevents it from wobbling beyond a certain angle, but it gets pretty ugly in there.

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do you get the good pumps? all my remans i get at the autozone tend to weep when they want to be replaced. (lesson here?)

it's never crossed my mind to loosen the pulley bolts with the belt still on... i want to make excuses... but... epic fail =\

xcm said:

do you get the good pumps? all my remans i get at the autozone tend to weep when they want to be replaced. (lesson here?)

it's never crossed my mind to loosen the pulley bolts with the belt still on... i want to make excuses... but... epic fail =\

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I've always gotten new pumps, but none of the replacements has failed (yet), so I don't know how they'll behave if they ever do. I've so far had failures in four different XJ's, and as I recall only one (87) leaked before it clanked. Maybe that's just random dumb luck, though, and since I've never gotten one with under 110 thousand miles on the clock, I can't be sure whether the pumps they came with were original, rebuilt, new, or what.