fan belt squealing.....aaaahh

[JAYGURNEY]

my old fan belt was squealing so i replaced....now thats squealing as well, i thought it wasnt tight enough so i made a makeshift bracket to hold the tensioner tight but its still really bad, im also losing lots of electrical power when the main headlights are on, ive had it checked by an auto electrician and theres no drainage, the battery is good and the alternators charging as it should be.....im pulling my hair out at this stage...its an e300 turbodiesel auto.......

can anyone shed any light???

 

[lynall]

You sure its the right belt as there are probably several different lengths.

Look at all the pullleys with the engine running is the belt running in the centre of each pulley? are any of the pulleys wobbling?



Lynall

 

[JAYGURNEY]

the motor factors say there is only 2 belts listed, with or without aircon. there is a big difference in length so they say you cant go wrong.....ive looked at the pulleys and the belt is running true and there doesnt seem to be any wobble i any of them, when i have the lights on the driver side lights are really dim and seem to go up and down with reference to the shine...dull then really dull then dull etc....i dont know..

 

[C230kompressor]

is the tentioner adjustable? or has it got a dampner?
my w202's have dampners and they get week and make the belt squeel!
i replaced the dampner and sorted the problem!

 

[JAYGURNEY]

yep its a dampener, did you have any problems with electrics? mines goes haywire when a load is on, eg full lights, shows up everything on the onboard computer...

 

[C230kompressor]

yep its a dampener, did you have any problems with electrics? mines goes haywire when a load is on, eg full lights, shows up everything on the onboard computer...

yea when i turned hard lock to lock all sorta lights came on! as the alternator was slipping!

 

[JAYGURNEY]

riteo i must get that checked, its doing my head in, thanks and ill keep you postered.
hopefully it cures it as the squealing must be the worst noise in the world....

 

[C230kompressor]

riteo i must get that checked, its doing my head in, thanks and ill keep you postered.
hopefully it cures it as the squealing must be the worst noise in the world....

hopefull will sort it!

 

[gil928]

I have a 98 e300 that I'm going thorough the same thing with at this time. I started with a bad alternator and then the noise started after I replaced the bad alternator. so I replaced the belt and the dampener and they have not helped. I have looked over all the pulleys and there alignment. I'm going to reinstall the old alternator to see if there is something wrong with the new part.
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[C230kompressor]

I have a 98 e300 that I'm going thorough the same thing with at this time. I started with a bad alternator and then the noise started after I replaced the bad alternator. so I replaced the belt and the dampener and they have not helped. I have looked over all the pulleys and there alignment. I'm going to reinstall the old alternator to see if there is something wrong with the new part.
​

yea might be worth a try!
does it squeel al the time?
and have you tryed WD40ing individual pullys?

 

[gil928]

yes I have tried belt dressing, wd 40 and a lot of brake clean to remove the dressing after it did not make a difference. My belt is not squealing at an ideal. at first it was only when driving but now it happens when I rev up the motor.

 

[C230kompressor]

prhaps a bearing squeel then?
is the water pump on that belt?

 

[Merc Owner 2B]

I would have suggested belt dressing but it looks like you tried that.

Also, is the belt genuine as the profile is a critical fit into the pulley. A slipping belt will cut a groove into the pulley with time rendering it useless. You could also try roughing the contact surface of the belt and pulley with sandpaper/emery. Also try reversing the direction of the belt (turning it around.)

 

[franey]

Have you checked everything is turning freely with the belt off?
Water pump?
Power Steering?
A/C Compressor?
Alternator?

 

[JAYGURNEY]

its a nightmare, mines only squeals when revved up or driving, never idling.....ive tried the belt really tight...really slack....no joy...funnily enough i never had this bother until i had my alternator off as the pulley needed replaced and it was then i changed the belt. strange. i didnt get my new belt through merc dealer as they were quoting 70 to the local shops 20, the guy i got the belt from assured me that the belt i bought was exactly same as genuine merc and its the gelt they use for 95% of all new cars. i think the make is gateway or gately..

 

[franey]

Gates.

 

[JAYGURNEY]

yep gates...

 

[C230kompressor]

so you changed the alternator pully?
or the alternator?

 

[franey]

You say you have replaced the alternator pulley, where did you get it from - part numbers etc?

Have you fitted it correctly?!

Again - have you checked everything turns freely?

Also, the belt tensioner lever - is that moving / free?

 

[JAYGURNEY]

the alternator pulley was replaced by an auto electrician, genuine part, the alternator itself was checked and was charging fine so just the pulley wheel replaced, the belt tensioner is moving free, something i did notice when changing belts was that the new belt was slightly longer than the old one,,,,very slightly