2001 1500 5.2L
So I noticed over the past few weeks, there has been some noise under the hood that has gotten a little more noticeable as time goes on.
I thought that the exhaust manifold heat shield(s) may be vibrating and causing a noise that one would think may be caused by heat shields vibrating (if that makes sense). After listening closely, I think the vibrating sound I am hearing is coming from the engine cooling fan. With the engine off, I can manually "wobble" the base of the whole fan/water pump hub thing about 1/16". I think this wobble is what is causing the noise. Sometimes it does not make any noise or wobble at all, but I imagine if the belt starts to creep to the outside of the pulley for the fan/waterpump, it will wobble since the pressure is towards the outside.

Anyone else have this problem?

 

Check the bolts holding the fan to the water pump, if these are tight then it is probably the water pump itself. If they are loose and they come out it will RUIN your day by taking out many things under the hood like radiator, wiring etc. Good luck.

 

Almost ashamed to admit it, but yes, I do. I just bought the truck 3 weeks ago, was told by the seller that the water pump had been recently replaced, which it appeared to be.
Well, I was checking fluids the other day and something compelled me to grab the fan...I can rock the whole clutch and WP pulley a good 1/8"...sigh...Checked the clutch, it's as tight as it should be, belt is riding normal, no visible leaks and truck running @ normal temp....I'll keep my eye on it, but I don't like it.....

 

Guess I have to check out the clutch bolts

 

When mine wobbled and made noise it was the water pump.

 

Yup, mine to. Should be no wobble at all. If nothing is loose, you need a new water pump. Its possible he put in a cheapo "remanufactured" pump from Autozone or some other junk parts place, which could have failed or be failing already.

I don't like remanned water pumps myself, I do new ones. For some things, remanned is OK, other things (this being one of them) you want new. Thats my way of thinking anyway.

 

a wobbly shaft is usually first- and causes a break in the seal, and shortly following that a nice coating of coolant all over your engine bay..

it's a bad pump..

take this opportunity to go efan.. in addition to the other GREAT benefits of having one, another not often mentioned is INCREASED WATER PUMP LIFE.... because, the weight of the fan isn't putting stress on the shaft.. and the shaft is usually where problems on WP's start..

 

So most likely water pump from what I'm gathering. Does that explain the lack of power etc? I'm not over heating at all either.

 

Lack of power is likely from another source. How many miles on the truck? How's the plenum look? (see the sticky at the top of this forum for LOTS of info in that regard) Last time it had a tuneup? Still got the cat? How old are the O2 sensors?

Yep, I am just full o' questions.

Welcome to DF!

 

might check your exhaust flange bolts for tightness. I'm not sure about that motor, but I've heard some of those manifolds and y-pipes don't have a gasket between them (rattling sound?). when those start to leak, they aren't always obvious and could cause you some power issues. stick your hand back there (cold engine of course) and feel for leaks.