I am getting absolutley nowhere with the replacement of the blower motor in my 1993 300E2.8, and it's driving me crazy.

I'm using the directions as listed on the official Mercedes-Benz CD manuals, the missing procedure 83-040 turned out to be 83-140 "Removal, reinstallation of air inlet cover". In section B, "as of 04/93" (as my car was made in June 1993), step 5 lists 'unscrew screws 549 and remove center divider".

However, on my car, the divider isn't removable. It's fastened on either side to other pieces of insulation and has tubing threaded through it in at least two places and doesn't seem to be removable. Without removing it, I can't get to the next step. The diagram in the car does seem to be of a different engine, the 3 litre, not the 2.8 104 engine, plus on the 2.8 litre car, there appear to be electrical cables running between the (allegedly) removable portion, that isn't mentioned in the manual.

At this point, I have two questions:
1) Has the design of this part of the firewall insulation changed between the 3 litre and 2.8 litre versions of the two cars and if so, what are the changes in the procedure to remove the air inlet cover?
2) Is this part exchangeable by a novice but well-prepared DIY'er, or should I just have the dealership replace it when I have the 150K service done next week?

Any ideas from anyone who has done this procedure on a 1993 300E2.8 before? Am I missing something obvious that will make this easier?

I take it by the lack of replies that no-one else owns a 2.8 litre 300E or if they do, they've never replaced a blower motor in one or it's not a DIY job.

Does anyone have any ideas at all, or should I just turn the whole thing over to the dealer on Tuesday?

The insulation behind the rear of the engine can be removed by removing 2 thumbscrews that look like a black plastic daisy in the middle of the partition. There are also 2 black flat plastic top screws that need to be removed from either end. Once the 4 screws are removed, just move the partition out of the way since removing it might be a PIA to put back in. The plastic intake vents can now be removed.

Just curious but was the black runber gasket that attaches to the wiper motor which runs across the length of the windshield glued down.


Hope this helps.

I was able to undo the two plastic 'daisy' screws, but the other two have the screw heads pressing against the metal parts of the firewall, so I can't get to the heads to unscrew them - unless they unfasten using the two plastic discs around the screw threads.

As for the rubber gasket - it may be glued on, as I've not managed to remove it completley. The manual claims that it's in a single elongated 'U' shape around the wiper motor (not the three seperate pieces like the pre 04/93 cars are), but mine completley surrounds the motor and there doesn't seem to be any obvious way to get it off.

Press firmly against the black disks with your fingers. It will be a tight squeeze but it doesn't take much effort to make them turn.

The black rubber gasket on the wiper motor is pressure fit into a channel on the black plastic reservoirs below it.

Did you ever need to replace the wire harness or head gasket on your 2.8?

Once I'd removed the black plastic discs, everything came out almost as the manual described.

The black rubber weatherstripping was held in place around the base of the wiper arm by a metal strap. I had to push the lower circular portion of the rubber under the lip of the air inlet cover in order to remove the cover, then unbolt the wiper assembly and the wiper motor came off along with the weatherstripping. I should have taken photos.

Typically though, the blower motor seems to be fine. Once I'd removed the blower motor housing, I tested it and heard a loud squealing from the motor. I disconnected the power cables to the motor, was able to turn the squirrel cages by hand, retested it and heard nothing. I then reconnected the power and tested a final time, and it started working (much to my simultaneous frustration and surprise).

So, my brand new Behr blower motor is still in it's box, waiting for the day it's called into service. In the meantime, I'm going to take my car out for a drive, now that I have air conditioning in it again. With one job off the list, the next is a good wash and wax at the weekend, and then on to tackling the power antenna that seems to be reluctant to extend.

As for the wire harness and head gasket - no, I haven't. When I was shopping for a Mercedes several years ago, I came across the head gasket issues in the 3 litre engines (103?) and decided that I was much better off with a slightly newer engine (104) that didn't have those problems. I've been bringing it to the dealer for it's major services and head gasket and wiring harness issues have never been mentioned, raised, or noted on any of the service sheets. I'll certainly inquire when the car's in for it's 150K service though.

Maybe this will help you:

http://skinnerbox.steaky.org/Service/W124/w124CD1/Program/Climate/83-556.pdf

__________________
1989 300CE Astralsilber/Schwarz
1992 300CE Schwarz/Schwarz

I already have that manual, on the two CD-set, plus I had the Haynes manual sent over for the UK W124 cars.

They don't help with trying to discover why the blower motor wasn't working one minute and then worked the next.

Do you smoke in the car? In my case, the previous owner did.

My guess is that the brushes and commutator need to be cleaned. When my blower motor stopped working, I was able to spin the blades and it started to work again as well. But since I had the blower out, I cleaned the brushes and commutator with alcohol and lubed the bearings on either end of the shaft. Brushes were a little worn but I didn't replace them. Contact cleaner would have been better but I did not have any on hand.

With hindsight, my non working blower motor was causing a short whenever I tried to turn the climate control on. The ABS light would turn on. Battery checked out ok. OVP was good too. I was going the check the ABS sensors next. But I finally realized that whenever I turned the climate control on the ABS light would turn on shortly after. Now everything is working perfectly.

Hope this helps others on this board.

As far as I know, no-one's smoked in the car - the previous owner was an older lady who traded it in for a newer Mercedes and she took great care of the car... the leather was barely worn, no scratches or tears in it at all.

And yes, I think it's the brushes too, and I thoroughly expect the motor to fail again someday at which point I'll replace it completley.

The clip that holds the motor in place seemed reluctant to be removed - what's the trick, and can you reuse the old one, or do you have to get a new one?

I used a very small screw driver and put the tip into the small metal hole on the end of the band. Then push down and away to pry it up. It took a little more time to clip the band back.

I put together the notes I made while getting through this repair and posted them to:

http://smharr4.dnsalias.net/index.php/Blower_Motor

I know, I should have photos but hopefully the text is explanation enough for those that are about to go through this. I'll post photos the next time I need to get to the blower motor.

Thanks to all those that helped me out in getting this repair completed!