Wronglane

About 2 months ago,we noticed a slight noise when first starting the truck in the mornings.The noise was so faint,I could never tell where it was coming from.The noise went away when vehicle warmed. This morning,I drove ot for the first time in a while,and its pretty loud now. Its definitley coming from the front of the motor somewhere.I am thinking it sounds like bearings starting to go bad.When looknig at the fan spinning from the side of the truck,it does not spin true,there is a very slight wobble. With the motor off and grabbing the fan in the middle,with force,I can very slightly wiggle it back and forth. I should NOT be able to do that,correct?

Any thoughts?

By the way,truck has 142,000 miles on it and teh water pump and timing chain were changed at 117,000 miles.

Wronglane

OK,been doing some research.Ithink its the bearings gonig on the "fan bracket",also called a false water pump idler bracket.Below is a pic outlined in red ink.Even at the club lexus price of $171.14 ,it seems expensive for what it is.

Has anyone replaced this themself?

Wronglane

Noone had to ever change theirs? As noted above,the part from Sewell with the CL discount is $171.14. RockAuto has the Aisin part for $103.79. Which should I go for? Is the Sewell part THAT much better or is it just marked up because its a factory part?

https://www.rockauto.com/catalog/x,c...parttype,11548

chiph9

First I've heard of this happening.

I would take a look at the belt tensioner while you're in there -- when bearings go bad, it's often because the tension was incorrect.

Chip H.

techrep

You sure you don't just need a new Fan Clutch...

Wronglane

How do you know if your tensioner is bad? Would you change it anyway with 142000 miles on the truck?

chiph9

At 142k miles, I would go ahead and change it just for grins, especially if I were in the area.

Normally, a tensioner loses strength over time, but I have heard of them getting locked into position from dirt or gunk, and this causes the belt to be too tight.

Chip H.

Wronglane

I do not think so. The noise has become louder with time and sounds like a bearing(s) going bad. IAlso,looking at the fan spin from the side while enging is running,it wobbles a bit.

Wronglane

I am going to change the serpentine belt too.Would you go with the factory oem part from Sewell or the Aisin part?

techrep

a good polly cog belt... like gatorback

chiph9

With 142k miles, I would go with the Aisin. They're more than likely the OEM for the part in any case.

For a belt, I like Gates.

Chip H.

Wronglane

This may be a silly question,but,does this fan bracket assembly(false water pump) have coolant running throught it or does it attach to the water pump in a way where fluid does NOT go thru it? No gaskets come with the part when orderng,so,I am confused about this.

Wronglane

I guess,noone knew the answe,so,I will answer for anyone else wondering since I have the part in my possession. No water rins thru this part. I had my local mechanic do this as I was strapped for time and needed to get this done as we are taing the truck to Toronto in a week. Around noon time,he called me to the shop to show me the belt tensioner. Spinning it by hand,it was making noise and I could rock the pulley from side to side. Replaced that also.Picking the truck up tomorrow.

techrep

The belt tensioner was probably your original noise ...