Noise from belts or bottom pulley

[cmm303]

Ever since I refurbed my cooling system March 2016 I have had a squeek from the region of the belts. It has gradually got worse over the year so I've decided to fix it.

• It is intermittent, but getting louder and more common over the year.
• Only happened after a cold start, typically first start of the day.
• Only happens at idle speed/v low revs. So if I pulled up at a junction, say after 1/4 mile, I'd hear the squeeks, but quiet after 3 miles.
• More likely with aircon on and sometimes worse, but not reliably.
• In March 2016, it had new belts, new pump, and the alternator has been bench tested since.

Having run out of enthusiasm after the radiator gave out May bank holiday I took it in to a garage for a service and asked them to sort it but then no noise (it wasn't a cold start), so nothing fixed. They said belts and tensioning looked ok.

Last week I replaced the three belts. First start, no noise, thought it was fixed.
2 days later, Friday, started up to go away for the weekend and I hear a couple of squeeks.
Started up to leave the camp site on Sunday and worse than Friday but by the time I had the roof down and ramps put away it had gone.
So it is a lot lot better than it was before changing the belts.

In case it wasn't the belts, I had a poke around while they were off:

• The a/c belt tensioner pulley runs smoothly with no obvious play (to me at least).
• Alternator, a/c compressor and water pump spin freely.
• Wondering if this could be the chirping described by Northern Bongalow caused by the rubber in the crankshaft pulley breaking down, I tried checking this for play. I could get the whole pulley to move a bit. I did a video as I don't really know if this is too much "give" or not. https://www.youtube.com/edit?o=U&video_id=_ren9ab6cgI. I couldn't see any obvious rubbing against the block/casing but doing it all from above didn't give the greatest view.

I guess I could run with the a/c belt off and see what happens over a few cold starts.
I'd welcome any comments and suggestions.

[rita]

Did you lubricate / pack the tensioner/jockey pulley bearings?.

Good Luck.

[cmm303]

Did you lubricate / pack the tensioner/jockey pulley bearings?.

Good Luck.

Nope, I didn't.
Looked clean and sealed up.
There was a large circlip on rearward face - is that how it comes apart?
I've a tin of old school high temp molybdenum grease, ok?

[Northern Bongolow]

cannot view the link, maybe cos i dont have an account or something.

[cmm303]

cannot view the link, maybe cos i dont have an account or something.

Aghh. It was set to public. Copied this link from a different place, any better?

https://youtu.be/_ren9ab6cgI

[Northern Bongolow]

yes that works thanks.
that movement is nothing to worry about at all but it cannot move that way anyway as it is hitting the outer (fixed pulley) it needs to be forced towards the engine casing. but the way really to test is rotational movement slack, especially in the early stages. remove the belts with it in park and from below try to rotate the 2 pulleys on the inner edge of the pulley, the pulley is a three belt jobbie, the front pulley is aircon and fixed to the pulley drive, and the rear engine side 2 are the water pump alternator and are rubber bonded to the pulley drive,
its the inner 2 groves that spin and chirp. forward and backwards movement is only detected later when it really starts to wear away.

http://igmaynard.co.uk/bongo/forum/view ... ey#p637393.

i would clean the old burnt rubber and road muck off all the pulleys with some belt cleaner or similar and a wire brush and check the idler bearings while it is in bits.

[wonkanoby]

thought my noise a while back was belts,turned out to bepower steering was very low on fluid

[Northern Bongolow]

not much point putting this up for you as you contributed but it may help other in the future. .

http://igmaynard.co.uk/bongo/forum/view ... 10#p666710

[cmm303]

Thanks for the advice and help.

Ady, your pic of the dismantled pulley makes me shudder everytime, but I had forgotten exactly which pulley was rubber mounted.
I was against time and went for the quick belt change. Clearly I'm going to have to put it up on ramps and take the bottom cover off.

I am suspicious that replacing the belts had a marked affect without completely resolving it.

[Northern Bongolow]

i always run the belts on the loose side rather than tighter knowing the tensioners and pulley are getting on a bit. check em regularly though as part of your weekly under bonnet checks.

[cmm303]

It's definitely the alternator+pump belts, removing the aircon belt made no difference. No noise with the alternator belts removed (very temporarily )
Crank pulley can be flexed about same amount forwards or backwards. Couldn't force rotational play of the two rear pulleys but it's awkward and I'm a weakling.

Tightened belts until squeaking faded. Slacken half a turn and it returned. The new belts had presumably bedded in or stretched, making them slack enough to make the noise which comes from the crank pulley area. I never realised how sensitive to tension this type of idling squeak could be.

In case it is more then just slack belts, tomorrow I'll try to remove the crank pulley - might have been this evening if some tw?t hadn't piled into the back of me whilst driving to a motor factor for tools.

[Northern Bongolow]

before you rip it apart again, squirt some water on the belts while they are running to see if its the belts or pulleys, if no change try the crank pulley with a good drink, you may get a change in tone or it stops which may help you in your search.

watch yer fingers.

[cmm303]

before you rip it apart again, squirt some water on the belts while they are running to see if its the belts or pulleys, if no change try the crank pulley with a good drink, you may get a change in tone or it stops which may help you in your search.

watch yer fingers.

Pinkies still attached
Just one belt on at mo so did this as is. Slackened belt so squeak is obvious. From underneath I briefly and lightly "misted" the belt and noise dropped immediately. Started to return after 30 secs or so. Belt is visibly (from underneath) flapping or vibrating.

Given the small amount of moisture needed to shut it up the next test is probably meaningless. However, I put me sprayer on pencil jet and aimed between the aircon groove and forward alternator groove on the crank pulley. Silence again but water was spraying out of everywhere! I also sprayed through the holes in the pulley with similar result.

Tightened the belt back up so noise just about goes. I think deflection on top belt run is just shy of 1cm pushing as hard as I can. Deflection on long run is getting on for 2cm with little effort. So maybe I've just been a pansy about tightening the belts!

Oh, and alternator pulley was slightly warm but so was the alternator body. Other pulleys cold.

Thanks Ady for your advice. If I've understood the logic correctly, it isn't looking like the pulley so I'll skip trying to remove that. And I've learnt a lesson about these belt tensions and about the garage that said they were fine!

[Northern Bongolow]

sounds like youve got there mate. as i said earlier i tended to run my belts loose rather than tight, obviously make sure they are good belts and clean and check weekly.

[cmm303]

Grrrr! This still haunts me! Fortunately Bongo hasn't had to do many miles this year.

I was directed to check that it's all in line by a few peeps. I didn't understand how the pulleys could be out of line until NB pointed out that there is a bush in one of the mounting lugs on the alternator that can be put in the wrong way. It is in the lug to the rear of the alternator and the front lug is tight against the face of the bracket. I.e. the alternator is as far towards the rear that the front bracket allows. There are no washers or other spacers apart from this one bush.

With the alternator out, I can see that the bush can only go in the rear lug. The bush has a flange at one end and on mine this is facing forwards. Logically this feels right to me but can anybody confirm?

The alternator page in lush projects does not show the mounting arrangement and I have run out of steam trying to find it on another page.

The engine hasn't been turned for a while and the belts have left contact marks on the pulley. The mark is shorter on one groove. Could my problems be down to mismatched belts? They were bought as a matched pair but when I put them on I noticed they weren't identical lengths and assumed that it must be good enough because the supplier (not Fury) is a major Bongo bits supplier. Maybe replace the belts, again?!!!!

Thanks
Chris