300E time for a new serpentine belt?? - PeachParts Mercedes-Benz Forum

mike690003 · #1 12-07-2003, 01:14 PM

Hello Board, for a few days now, I have been noticing a "chirping" noise under my hood. Well Today I inspected the serpentine belt and noticed that it had a 2-inch split in the middle.

Will this pose a major hazard to my car, or can it be driven as is?

The outer ridges of the belt are not worn, but that small split in the middle is staring me in the face.

Is replacing the serpentine belt a DIY, or does it require a professional?

hawkpfc2 · #2 12-07-2003, 01:27 PM

change it ASAP or you might lose operation of cooling fans, a/c, power steering, alternator etc. how many miles does your car have? you may want to have the drive belt tensioner checked.

chazola · #3 12-07-2003, 01:29 PM

I'd repalce it rather than wait for it to go and really bugger up your engine. The part is not expensive but installing it is a bit of a pain. I had my local mechanic do mine and the tensioner at the same time for piece of mind.

mike690003 · #4 12-07-2003, 01:40 PM

How long (labor wise) will it take to replace this belt??

chazola · #5 12-07-2003, 02:00 PM

unfortunately the tensioner and belt took 3 hours labour time, and the tensioners themselves are the expensive bit. All in all it came to around $400 for that repair, though if you only need a belt and can change it yourself it'll be about a 10th of that cost! It did make the steering feel much better and stop the squeaking i had on start-up nicely though:-)
I'm fairly new to the 300e so one of the senior members will know more on how to replace it yourself I'm sure...

psfred · #6 12-07-2003, 05:34 PM

Replacement is fairly easy, but the tensioner is the sticky bit.

You can test the tensioner when you remove the belt, but if you have 100,000 miles plus on the car without a new one, expect to get it. I'd buy one anyway, they don't go bad sitting and you will then have it if you need it.

Changing the belt if the tensioner is good isn't bad:

Remove fan and clutch, along with radiator shroud. Loosen the large (19 mm I think) bolt on the tensioner and unscrew the adjusting nut beside the water pump. While doing so, watch the pointer on the little "ramp scale" on the tensioner. If it moves back clockwise to the line before the ramp, all is cool and you can re-use it.

If, however, it goes only part way back or doesn't move, the tensioner is kaput and you will have to replace it.

It's held on by the big bolt in the center, and a bolt on the right side of the bracket, two on the other. You must remove the adjusting nut. Make sure you get the adjuster on correctly, or you will snap it. You also need to remove the tensioner shock.

Installation is the reverse. Loop belt around the pulleys, and remember that the shock will push the tensioner arm all the way "tight" and will have to be compressed manually to get the belt on. Use the adjuster to pull the pointer on the tensioner up the top of the "ramp", then tighten the big bolt.

Peter

mike690003 · #7 12-07-2003, 10:02 PM

One more question: My cars belt squeals a little and it sounds like crickets are under my hood. Is the belt too tight or too loose??

psfred · #8 12-07-2003, 10:27 PM

Mike:

Almost dead certain it's too loose, and slipping. Can also sound almost like something is knocking in the engine -- the TE did.

Makes me think bad tensioner -- the shock will hold the belt tight enough to work, with some slippage, if the tensioner goes. Ditton on the diesel.

Peter

hawkpfc2 · #9 12-07-2003, 11:54 PM

yea, sometimes they will only make noises at startup which is what happened to my 300SE just recently. almost like a timing chain tensioner but it was the drive belt tensioner

G-Benz · #10 12-08-2003, 01:34 PM

I was able to change my belt in about 30 minutes w/o loosening the tensioner. I wouldn't do this if the belt tension was questionable otherwise...

...I used a screwdriver to gently coax the belt to slide off one of the pulleys...easiest to do on one of the pulleys that engages the smooth side instead of the grooved side.

I will admit that I was in the process of replacing an alternator...I had removed the fan blades and fan shroud for easier access.

300EE320 · #11 12-08-2003, 04:31 PM

Mine ate a belt and I ended up changing it in the parking lot at midnight to avoid leaving the car overnight! The worst part was that it wrapped itself around the pullys and it was a bear to get the pieces out. Definitely change it now before it's too late.