How much play in water pump is OK?
 

I have done a lot of research here and other places regarding water pumps, however cannot find guidance on what I think is early indication of water pump failure.

My '01 986S has developed a sound over the past couple of weeks that has increased intensity, is a constant whirr that follows rpm. Sounds sort of like very noisy tires (not the cause as the sound goes away when coasting).

Sound seems to come from passenger side front area of engine. I suspected something associated with the serpentine belt, so I checked it out.

All the pulleys seem good, except the water pump has some play in it. When I grab the pulley and yank it back and forth, there is a little knocking sound and it seems to move about .5mm (swag). No leaks that I can see.

Is some play allowable in a water pump at the pulley, or should it be completely tight?

Much appreciated!

Gary

The water pump should have no play. Take the Serp belt off when the car is cold, start the car and if the sound goes away, its something the serp belt is driving, the wp, compressor etc. Put the serp belt back on and listen to all the accessories with a stethoscope. It will be apparent what accessory is making the noise.

that's what happened to mine. the impellers didn't tear apart, but there was a wobble in the pump and a weird noise that got worse as the RPMs increased.

get it replaced ASAP before it's too late.

+1 on replace water pump. If it wobbles and the impellers chip, the loose pieces will cause you lots of headaches especially if they block a water channel in the engine.