squeal when accelerating from rest
 

I am hearing a squealing sound when I accelerate from rest. It stops when I hit about 15-20 mph. If I slow down to 5-10 mph and then accelerate again, the sound kicks back in until I hit 15-20 mph. Does anyone have any thoughts as to what may be causing it? Thanks.

Dan

'84 300 SD

Could be slipping belts.

Matt is probably right. If you can turn the alternator pulley with the engine off the belt is too loose. Alternator belts love to squeel. If not sure just run a bar of soap along the v portion of the belt with the engine stopped of course. It acts to temporarily increase traction of the belt and again if the squeel is eliminated by it adjust or change the belt if worn or damaged. I find in most cars It is a common problem and perhaps one of the reasons why they went to self adjusting serpentine belts years ago. I also have always wondered if it is a squeel or that a shreik might be a better description but everyone always seems to call it a squeel. :D

I don't know, with these speedy machines maybe you're just giving it a little too much juice...:D

Squeal
 

Thanks for the advice. I will check the belts.

I was going to say ease up on the pedal too :D

After shredding 3 sets of rear tires on my SD by accidentally pressing the pedal too hard on takeoff, I learned to take it easy. :D :D ;)







Seriously though, its probably the belts slipping on either the alternator or A/C compressor.

Emegency brake??? Try applying the brake going slow in a empty parking lot, sometimes this will clean up the drum and stop the squeal. Just a thought.

It could be the e-brake or the belts. I've had both. Sometimes I get this not-noticable-to-anyone-but-me squeek from the rear at highway speeds. Hitting the e-brake for a second then releasing clears it right up. Also, when I had only one alternator/fan belt, which was also a little loose, it would squeeek on takeoff with the lights on or the fan on high. Its easy enough to tighten the belts.

I've had both the AC and alternator pump do this, they usually are just a tad loose.

Personally when I have to do something that involves belt changing or loosening, I always try to leave them a bit on the loose side, then I tighten them slightly if they squeak or squeal until it goes away.....that way I know I am putting the least amount of pressure on the engine pulley possible, gotta prevent that carrier bolt shearing! :D (yes I am very paranoid)

its an alt/fan belt
 

Its a late reply, I know, but I haven't looked at my car for awhile. Its one of the alternator/fan belts. There are 2 that appear to turn the same bearings, so I am unsure how to tighten one and not the other, since only one is loose:confused: . Perhaps its a good time to replace all 3 that I have. Surprisingly, I don't seem to have a belt that goes to an AC compressor (not even sure if I have one!). The other belt that I do have goes to the power steering pump.

The loose belt probably stretched a bit with age more than the other. I know the 2 belts on my sd have never been the same tension.

belts
 

Good to know that its fairly common that both drive belts may be at different tensions due to age.

On another note, does anyone else not have an AC belt? I can't figure out why I don't have one, but it partly explains why I don't have AC.

I don't
 

have an AC belt. Because someone removed the compressor, long before I got the car. :rolleyes:

AC Belt
 

A friend I met on this forum, jbaj, told me that my car (an '84 300 SD) doesn't have an AC belt, although it does have a compressor. I didn't get the chance yet to ask him what powers the compressor in this case. Does anyone know?

It is missing it's belt.

May be gone because the A/C does not work (Was removed by past owner), the compressor is locked up, or the belt was old and fell off.

Thanks, ForcedInduction,

I realize that I misunderstood what my friend had written. It does appear that I am missing an AC belt as well as the AC compressor pulley. Not sure why, but my AC may be long dead and someone just pulled off the belt and pulley...

I guess I will have to address that later. Right now I am in the middle of replacing my drive belts (the 3 that I have). I have been using pindelski.com, if any one else is interested in that very helpful site.

belts replaced
 

I managed to replace the 2 alternator belts and the power steering belt and I tightened them up (but didn't over-tighten them). No more squeal!

That's 1 belt per month? :P