The V8 Owners Forum -

Hi All,

I'm running a 4.6 with the new GEMS front timing cover and reverse rotation water pump. I've designed a 'unique' pulley system to also drive the supercharger pulley. I reversed the water pump pulley and also spaced it approx 10mm in order to line all the pulleys up. I'm using the crank pulley of an intermediate cover. I tried using the gems crank pulley at first but that didn't have enough offset and brought my supercharger outlet in line with No1 exhaust header! I knew changing the water pump pulley and increasing it's overhang load would decrease it's life but it's my weekend car and will only do a couple thousand miles a year.



All was well (quiet), just finished running in my cam, after driving it on the road for about 30 miles the water pump has started squealing when cold. This strangley goes away as the coolant temp rises to somewhere past 80degs.
Does anyone know how the bearings are arranded in it? singular/double/replacable?
I'm asuming the noise is from the bearings?
It is an aftermarket water pump, I was thinking of maybe rebuilding it with some good quality SKF type bearings, I'm guessing it will have come with cheap chinese bearings!
Has anyone rebuilt their water pump? Is it possible?
Does that pump hold a viscus fan when installed on rangerovers and disco's? If yes, then i'd have thought the bearings would be stronger?
Anyother options anywone could come up with i'm all ears. I thought of going the electric pump route which i'd be happy to do but space is really tight down there (Dax Rush).

A lot of question I know but any help/ thoughts much appreciated.
Tom.

It's trying to pump more water than can flow around the bypass until the stat opens?

The belt is thus managing to slip intil there is less back pressure from the water whence it all comes quiet

wll that would be my guess

Ian

I you sure its the bearings squealing !!! - usually noise = heat and that would kill the bearings in 5 minutes flat

I wonder if it squeals/slips until the belt warms up - In the past I have used a belt grip spray from Fenner IIRC - a dab of that when cold or WD40 for that matter will tell you ifs its an internal bearing load or external belt grip issue.

Andrew

Ok thanks guys, i'll re-check the tension and although tight maybe it is slipping. I've used a sprung tensioner so I can (carefully!) slacken the belt whilst running to see?

Just strange it didn't do it when I first started it!

Tom.

new belts always seem to stretch a little once mounted.
There is also a degree of initial wear of the belt as it adapts to the old pulley's.
These 2 factors cause the belt to lose initial tension.
After re-tensioning they will last a long time without slipping.

Spray it with wd40 or whatever, if its the belt it will silence it for a couple of mins untill the WD comes off which it will quicly.

I'm with Ian on this one. The pump is loaded due to a closed stat, and the belt needs retensioning post fit.

if thats a kit car like mine (westfield) then a lot of 4.6 owners have had a problems with the water pump pulley slipping...

As like mine it runs reversed....so people have recommend that the smooth area of the pully should be knurled to prevent slippage.

As the belt slipping can give you the same sound.

Personnally not had mine done, as it doesnt slip, but its an option if it ever does.

hope this helps

scott

Seight-V8 wrote:....so people have recommend that the smooth area of the pully should be knurled to prevent slippage.scott

That should make a difference, for sure.