Newbie needs help! - PeachParts Mercedes-Benz Forum

#1 12-06-2002, 12:45 AM

This is my first Benz ('87 300 SDL) so I need all the help I can get.

Four questions:

1. What does the hood switch above the mono valve do? Do some Benz's have hood lights (mine doesn't)?

2. When my glow plugs heat, the ol' girl starts just fine, but I usually have to cycle the ignition key four or five times to get them to heat. Why must I play this game?

3. My tach has been dead since day one. Where do I start looking for the gremlin?

4. Driver door (only) must be slammed in order to shut completely. Do you know how much it hurts to have to slam an MB door? On American cars it's usually worn hinge pins, but these hinges seem tight as new. Is there an adjustment for this or do I have some parts that need replacing?

Thanks in advance for your help, guys. I am much obliged.

CHAPP · #2 12-06-2002, 06:43 AM

1. don't know

2. My glowplugs do the same thing...and sometimes the light will not come on at all. My mechanic found the problem in the glowplug relay box. He made a quick fix (hotwire button) that I still use after 2 years. He recommended replacing the relay box.

3. I would try the fusebox first for the tach.

4. don't know...but would check for any thing loose, broke or worn looking. I have adjusted doors on other cars...mark one side of the door so you can see where the adjustment is needed. I went to a large junkyard and every door I slammed on MB's sounded with a loud thump...even the old junkers. I was so impressed I opened and closed all the MB doors I could find to see if I can find any that would not close...every door was fine on 7-8 cars.

#3 12-06-2002, 07:26 AM

1. The hood switch is for the burglar alarm, there is no hood light. I think MB decided that their owners are too ignorant to work on their own cars, so they left out the hood light.

2. I would say that it is about a 98% chance that an all new set of glow plugs would correct this problem.

3. Sorry, but I can't help you on this one. I would think checking all the fuses would be a good place to start, though.

4. No, you should most definitely NOT need to slam your door. It needs adjusting. Using an Allen (I think it is 5MM) loosen the striker piece on the door jamb and move it around until you find the right position where it opens and closes easily but has no wind noise. If the car has ever been in an accident, you may end up having to adjust the hinge position as well.

Good luck,

leathermang · #4 12-06-2002, 01:45 PM

LOL, yes it does hurt to have to slam the doors... You may need to replace the item on the door jam.. check to see if the little plastic deal on the underside is still all there... compare with your other doors .... often it breaks off on the part which causes the final locking of the door mechanism which keeps everything tight...these are pretty easy to replace...usually you just drill out the flush head allen bolts which are holding it on and put one from a junk yard back on it... or grab it from your golden parts car like I did..Usually one of them won't come out with the wrench...

#5 12-06-2002, 02:50 PM

Dave,

leathermang offered some great illustrated instructions. I just want to add that even though your striker will not look exactly like the one in his illustration, his instructions still apply.

Have a great day,

Aaron · #6 12-06-2002, 03:17 PM

On the glow plugs, I would first check the 80amp blade fuse inside the relay. Sometimes they get hairline cracks in them which you can't see even if you look close. Take a small flatblade screwdriver and lift the fuse up a little to see if it splits (probably will). The fix is easy enough, just unscrew it and put a new one in (key OFF obviously).

On the door, you do need to adjust the striker plate for it to close properly. Common malady of 126s.

On the tach, that car should have the little black "trashcan" on the driver's side inner fender. That will need to be replaced with a new one for the tach to function properly.

And yes, the hood switch is for the alarm.

dmorrison · #7 12-09-2002, 12:58 AM

Slamming the door.
Is this your first Mercedes??
I find that you have to apply more force when you close a Mercedes then American cars. My father-inlaw would always have to close the door a second time because he uses the same force, out of habit, that he uses on his Mercury. And he would always yell at me not to slam his doors when we drive in his car. I find that people who have american cars don't apply enough force for the Mercedes.
This I see happening in all my mercedes. From the 82 to the 99.
The Mercedes tend to be a little more air tight then American cars. Compare all your doors closing force to each other. When you close it as the LAST door. That when the air pressure has the greatest effect. If you find that they all close the same then I would say your ok. If not then yes, look at the door adjustments suggested in the posts here.
Dave

#8 12-09-2002, 05:27 PM

Aaron (or anyone else who wants to try bailing me out!),

Thanks for your suggestions.

2. On my glow plug problem you said to check the 80 Amp blade fuse first. It took me awhile to locate it, but I finally did and it appears solid. I removed it and tested it w/ my meter and it's good physically and electrically. Now what?

3. Regarding my dead tach you said to replace the 'little black trashcan' on the driver's side inner fender. Try as I might I just can't seem to find what you're referring to. Can you be more specific? My car is a W126.

I have already printed out some of the MB Repair Manual pages and have them w/ me at my sister's here in WI where I've been stranded since the Saturday after Thanksgiving. First my heater went out (bad mono valve), then the alternator burned out! I've got one coming in tomorrow, as no one here in Central WI had one in stock.

Maybe you can refer me to a specific picture or diagram in the Manual for either or both of these problems.

I can live w/o the tach, but thought that as long as I've got her in the hospital I might as well fix some of this other stuff. I like everything to work, you know what I mean?

Thanks for whatever ideas you can give me.