Water pump screeching?

[TomoHawk]

When I start the engine, and then give it a pop or two, it sounds like the water pump is screeching? But then if I give it a minute to warm up it will stop screeching. Also, there's no screeching when you drive (at any RPM) and from a start as long as you don't nail the throttle.

This is confusing. Ususally the water pump (Chevys only) starts sreeching, and gets worse with time. Any ideas on this?

thx

[FirstGenZ]

Bad belt !!!!!!!!!!!!!!

[Alex 240Z]

Check belt could be loose or needs replacing !!!!!!

[TomoHawk]

Don't think it's the water pump belt. It's a new belt.

[hls30.com]

Check the tension-too loose and you will get what you have...

Will

[whew41]

From my experience with other cars sometimes the bearing in the pump will show wear my screeching and then stop but given time the screeching will get longer and longer. Just my two cents if it helps

[TomoHawk]

Check the tension-too loose and you will get what you have...

That's the only thing I could think of. There is a new alternator & belt, so maybe the belt could be either too loose or too tight. What is the correct "tightness?"

[=Resurected280=]

I know this is for a different car but I had a Crown Vic that did exactly what your car is doing, but it ended up being the bearing on the tensioner pulley was going bad, and it had a new belt on it at the time. So I would vote some sort of bearing on this one.

Also are you losing any antifreeze there? When the bearing on the water pump on my 280Z went there was some antifreeze leaking out of it around the bearing/fan mounting area.

Good Luck =)

[TomoHawk]

That's another possibility I thought of-

Maybe the fan clutch? If it w wasn't free-wheeling well enough, a quick jab of throrrle could cause the fan to slip, with the noise meaning it was dry inside.

I've coolant in there, and it should be properly mixed. But I'm still going to geet it flushed (bi-annual maintenence on that.)

I'm headed over to the service place that installed my alternator to have them look at the belt. But first I'll look into the Haynes book to see what the tension should be like. "Tight" like as in the usual for a domestic car doesn't seem right to me.

thx.

[sblake01]

From the 1978 280Z FSM, though i've never actually measured, it's sort of a feel thing. One other thing, I have found that aftermarket components, like alternators/water pumps from Kragen, Autozone etc. have a tendency to be noisy and that's anothter area where I only use OEM when available.

[mlc240z]

if it's only screeches on sudden acceleration, i'd lean toward the belt too loose idea.

retighten and check again.

if it slips too much, there is a possibility the belt or pulley could also be glazed. this would definitely cause noise.

you could try a shot of belt dressing to test if this quiets it.

with a new alternator pulley, could be the paint interfering with good contact with the belt.

sand the pulley down to bare metal to test if it's the paint.

in my experience, when water pump bearings go/are going they usually emit a constant low moan or growl with the emphasis on constant. sharp screeching from a bearing is usually when they're dry/really damaged and it wouldn't go away when you eased off the gas.

this is not from Z experience, just other cars, so i admit i could be way off base.

hope you get it fixed Tomo, and let us know how it turns out.

[Pir0San]

It's more than likely your belt, make sure that both pulleys are clean and free of grease.