I recently replaced my old leaking water pump with a auto zone replacement(which from what I read here was a bad choice)and doesn't leak anymore but I noticed that when my engine thermostat opens up it makes the engine run rougher and sort of miss, also the serpinte belt tensioner goes crazy, I just replaced it recently, the car runs fine except when the water pump is activated, so my guess is that its a bad one
1990 rs camaro
V6 3.1
thanks

 

Help me understand.....you have a water pump that can be "activated" ??


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ASE Mechanic/Machinist/Smog Tech

1999 NBM Trans Am
1986 Chevy 3/4 ton pick up
1981 corvette
1995 Kawi ZX6R
and 2 POS commuters...

R.I.P. #3
"He can see air"

[This message has been edited by Engineboy (edited November 26, 2001).]

 

If you have a belt-driven waterpump, which you probably do, it's never "activated" or "deactivated" -- It's always churning water. Whether or not it goes through the engine block is up to the thermostat.

Usually, you can't tell when the thermostat opens. It doesn't make an audible "CLICK" and it doesn't change engine RPM's. However... If the fan were to come on, that does cause a slight drop in RPM's, and, if things aren't working right, could cause other problems as well. (Could be draining too much power off the alternator.) Also.. Are you sure it's not the AC clutch engaging? When that happens, RPM's drop, and the tensioner gets somewhat jerky.

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

DSaint, which water pump did you get? I've got the HP one, and it's been doing fine after about 1-1/2 year. But yeah, like these guys said, from what you described I would suspect the fan or the A/C causing those symptoms before the pump doing that. Usually a bad/defective pump will either leak, or sound like it's falling apart with the occasional puking coolant bottle.

[This message has been edited by eightTfourTA (edited November 26, 2001).]

 

What I meant to say was that when my temp reaches 200 I can see the water pump slow down and the tensioner gets somewhat jerky.
Enkil I think you may have a point, how do you stop the ac clutch from engaging. eightTfourTA I forgot what brand it was.Thanks