Idler pulley bearing

[mickstanz]

Once again my Nav has a problem.. starting to think i bought a lemon..

Im getting a noise on/off from my belts/alternator area. I thought it might be the bearings in the idler pulley (alternator belt), took it off and sure enough there was a fair bit of play in one of the bearings. Pressed the old bearings out, and maybe somebody here can answer this for me but is the inside bore of that pulley straight or does it have grooves or anything? Because mine had a slot all the way round where the bearing sat, and when i knocked in the new bearing it was tight until i hit that slot then i could easily move the bearing around. It only tightened up once i put the second bearing in. Put Loktite on them for good measure (should have used nu-metal) and put the pulley back onto the engine..

Problem was solved, until a quick 10km test run it was back, and now theres a bit of play in the same bearing again, my thoughts are and what im hoping somebody can tell me is that the pulley got flogged out with the original bearing and now the new one isnt seating how it should because of the groove its sitting in. Or have a just done something wrong?

Im thinking replace both idler pulleys (the power steering one as well while im at it) with Dayco Nuline pulleys - Product codes EP159 and EP160. Worth replacing belts while im at it? Have a spare set here already.

Shouldnt be the alternator pulley, was replaced a couple thousand (easy) kms ago.

 

[JPMC]

Are you sure it's not just the belt?

I had a similar problem in my D40.
I initially thought it was the belt and put some soap on it and it became quiet but them half an hour or so later it slowly came back and made more noise the longer I left it and then as I added more soap it made no difference.
The top idler pulley looked to have lots of play and I thought maybe it was that but when I removed the belt although it was wobbly it wasn't making any noise so on the off chance I replaced the belt even though it looked fine.
Turns out it was stretched about 3cm longer than it should have been and once the new belt was on all was quiet (and the pulley still wobbles).

 

[mickstanz]

Quick question hopefully someone can help me out.. the idler pulley on the AC belt.. the bolt that goes through the pulley is extremely tight, its not left hand thread or something is it? Got it soaking in wd40 now but its still tight. Need to loosen it so i can try changing the belts to try stop this noise. Cheers!

 

[jonney]

should be a normal right hand thread. does it have a lock nut on the outer side of pulley ? if so you need to losen it then undo the bolt.

 

[mickstanz]

Got the but off alright, replaced both pulleys and belts.. noise still there.. went for a test drive and the only time i can hear it is when the engines really labouring, like if i go from 2nd gear to 4th and the rpm drop etc and the engine chugs along, i can hear a squeaking noise. When stationary idling every so often itll give a short chirp as well. What other bearings are there? Fan, ac? Or maybe the water pump or something?

 

[Stelianos]

are you sure if not just a bad belt or faulty tensioner which allows the belt to slip or something like that? these belts have graphite on them so sometimes they just knock.

 

[mickstanz]

I think the belts and tensioners are alright.. i think i need to possibly start looking at fan/ac clutches and maybe wayer pump, although the noise (which is now almost constant after driving 50km) doesnt seem to be related to the ac clutch engaging.
Have found this test to possibly check the fan.. (not 100% sure its going to work yet will try after work)

Auto Active Test
DESCRIPTION
In auto active test mode, operation inspection can be performed when IPDM E/R sends a drive signal to
the following systems:
– Rear window defogger
– Front wiper
– Tail lamps, front fog lamps, parking lamps and license plate lamps
– Headlamps (HI, LO)
– A/C compressor (magnetic clutch)
– Cooling fan
– Oil pressure warning lamp
OPERATION PROCEDURE
1. Close hood and front door passenger side, and then lift wiper arms away from windshield (to prevent
glass damage by wiper operation).
NOTE:
When auto active test is performed with hood opened, sprinkle water on windshield beforehand.
2. Turn ignition switch OFF.
3. Turn ignition switch ON and, within 20 seconds, press driver's door switch 10 times (close other doors).
Then turn ignition switch OFF.
4. Turn ignition switch ON within 10 seconds after ignition switch OFF.
5. When auto active test mode is actuated, oil pressure warning lamp starts blinking.
6. After a series of operations is repeated three times, auto active test is completed.
NOTE:
When auto active test mode has to be cancelled halfway, turn ignition switch OFF.

During this test the cooling fan should run for 5 seconds on Low and then 5 seconds on High on each cycle of which there is 3.

 

[bods]

That test won't help you for the clutch fan though. Only the little electric thermo fan that helps with cooling the ac condensor at low speed or when stopped...

 

[mickstanz]

Yeah i read it while at work but can see now its not going to test what i need it to.. i think im just going to have to drive it until something goes bang..

 

[bods]

Any difference running it with all belts removed? Or have any of the parts you have changed made any difference to the occurence of the noise?

 

[mickstanz]

Update: SOLVED (?)

Thought the problem might have fixed itself over the last few weeks and about a 1000km including some towing. Got to work today and i thought my engine was about to blow up from the noise it was making.

Suspected noise was coming from alternator, loosened belt off, spun it over clockwise, no problem, spun it fast clockwise then stopped it quick and it growled like crazy. Then spinning it anti clockwise gave the same growl so.. time for a new alternator (again!)

I initially ruled out the alternator as its only a few months/less then 5000km old. Not 100% sure what went wrong, im guessing bearing by the noise, or clutch, im not 100% how they work.

I dont think i wasted my time though as i wasnt happy with the amount of play in the bearings in the pulleys iv replaced.

Gearing up for a big trip up The Gibb River Road next year so hopefully work out all the kinks before then! Thanks again for any input given, will post up again once alternator is replaced just to confirm but im off to Africa for a month so will be a little while. Cheers