I've got a really bad wobble in my water pump pulley that is getting worse and I figure I need to get this sorted out before I blow a headgasket in the McDonalds drive thru. I know its not being caused by the harmonic balancer (crankshaft vibration dampener) because I just replaced that.

My question: Is it possible that only the pulley is going bad, and I can just replace that instead of the entire water pump? If so I'd like to first remove the pulley I have now and re-install it with the proper torque settings and all that just so I can make sure it wasn't knocked loose at some point (which wouldn't surprise me...)

 

The pulley is bolted to the water pump. So the only way the pulley would wobble without it being the pump, The bolts on the pulley would have to be missing or really loose. Or the pulley is completely bent. So more then likely you will be changing out the pump.

 

I'm looking at the mechanics' manual and apparently the pulley is bolted to the shaft that drives the water pump impeller, from the looks of things the pump would have to be pretty wrecked to wobble around like that, I suppose its possible but considering that its summer and I haven't overheated... at least, as far as I know, all I have are idiot lights that may or may not work.

What causes water pump failure? Bad bearings?
Is it worthwhile to remove the pulley and replace it or should I just go for the whole water pump? The pump costs about $45 it seems but I'd prefer to save the money if I can.

 

Like I said the pulley would only wobble if itbent or the bolts are loose or coming off. You have bad bearing in the pump.

 

Alright then, I guess I will just order a new pump and thermostat. Any manufacturers that you recommend?

 

I went with a NAPA water pump and the experienced guys on here suggest grabbing the OEM thermostat from the dealer.

 

Yep. Bad bearings are often caused by too much tension on the belt. You need enough to stop slipping, but no more.

Many an alternator and water pump has had a too-short life because of somebody thinking tighter is better.

 

Like $15 @ NAPA

180-200 lbs for a new belt, 140-160 for an old one.

 

Ah, so belt tension can cause this? My belt is on pretty tight right now but still follows the "flex one-half inch" rule. I was frustrated because before, I could hear it momentarily slipping and headlights dim slightly if I turned on the heater.

Hopefully I can get to NAPA some time, I think they are open 11am to 2pm minus lunch break and tea time. Ha.

 

It can cause the problem. But you have to remember it is a moving part and moving parts ware out. As for the light dimming the bad pump bearing can cause that problem. Since the bearings are bad it will cause the belt to be loose which in turn will cause the belt to slip on the alternator.