87 w126 cold weather gremlins
 

1 - My 87 420 SEL has a rather bizarre issue. If it's 30 degrees or colder outside I have to unlock my doors using the trunk or passenger door otherwise my factory MB alarm goes off! I've never taken apart a MB door lock tumbler, but i'm guessing there's a resistor or something in there that's not getting a good signal when it's cold. any advice?

2 - The sunroof rattles like theres a little screw in a rattling in a tin can. if i put my hand on the headliner (on the sunroof) even just lightly, the noise goes away. How hard would it be take the sunroof apart to find out what the heck is in there making noise?

Thanks, any help is appreciated.

btw i have 71k on this badboy now and it still drives like a dream. http://www.peachparts.com/shopforum/tech-help/307171-first-time-benz-owner-1987-420-sel.html

1) There's no resistor in the door lock, only a contact switch. Does it help if you force the key against the stop?

2) Open the sunroof 1/3 to 1/2 way. Pull down the leading edge of the ceiling liner on the sunroof panel. You're dislodging 4 or 5 friction pins. When the forward edge is released, pull it forward as much as you can then while holding the liner slide the sunroof all the way open. I'm not sure if there's a better way to do this but I lay a clean towel over the roof section between the windshield and sunroof opening and pull the liner up and out. You can see most of the sunroof mechanism without taking things apart that have to be aligned on installation. When you put back the liner, note the 2 ski clips (they look like skis) on the trailing edge. Make sure they're oriented so the tilt function works properly.

Sixto
87 300D

If you are new to the M116/7s, make sure to change those timing chain guides.

It's typically agreed that the alarms on the W126, especially the Generation I, are not worth the trouble. I've got a 1984 300 SD and hooked up the alarm for the first time during my ownership after replacing the passenger door handle. It worked great for about a week. Then it rained and as I was driving down the road the alarm started going off. It continued to sporadically do so all the way home.

There are a few things you can check out but you'll probably be best to just disconnect the alarm. You can disconnect it by pulling up the passenger front carpeting, floor mat and beneath, and there should be an alarm controller in a black box. On the Generation I it is beneath a black plastic panel mounted almost vertically against the firewall.

Your problem might be water slipping through the window seals (which is normal). Unfortunately, if water gets into the two-pin connection that connects the car wiring to the door handle and tumbler, the alarm will be erratic. That was probably what was going on with mine.

The Generation II W126 alarms are more reliable so if you want to dump $250 bucks buy a new driver side door handle (which includes the alarm wiring and tumbler) and install it after removing the door panel. The control unit on the Generation Is are typically erratic, too, whereas your car, a Generation II, does not have this flaw. I've got a Generation II 420 SEL and have never had an issue with the alarm even though it is hooked up and operational.

Good luck

Its not that big a deal.
 

Find the round black plastic snap on button. It is on the strike end of the door about where the lock is. Flip it out and unscrew the little bolt which is hidden underneath.

Put a block of wood inside the outer handle and the chrome body the handle is mounted on. Strike the wood hard enough to move the entire outer handle forward (toward the front of the car).

Put the key in the lockset and twist it clockwise about 50 degrees while pulling gently on the handle assembly. A little back and forth motion will bring the entire assembly out of the door body. Take it easy here. Attached to the handle is a wire with a junction. Just below the opening there is a carriage which hold the wire junction. It is likely your problem is moisture or a broken or skinned wire.

Consider the attachment.

The first time I tried this took me two beers. The second time I didn't even get a sip.

X2
 

A 380 SE was my second Benz and first gasser. One of those $10 plastic parts cost me a valve job, half a dozen valves and a piston.

Great info on the door handle removal.

On the valve guides, every W126 V8 I see in the yards has a broken upper guide on the driver's bank. Sad. Some of these cars are downright CLEAN with great paint and interiors.

The handle removal was straight out of the service CD. I got those to run on a 64bit windows 7 os using google chrome to open them with. My sons freaked.

Had I any idea that my beautiful Black on grey 85 380SE was in harm's way I would have changed the chain and guides the day I bought it. Ignorance is no excuse for breaking the law or driving a 116 without replacing the chain guides once a year.

thanks for all the tips
 

Thanks for all the tips on the sunroof, door locks and timing chain guide.
I have not replaced the chain guides. Can someone drop me a link to a how-to? Thanks.

Is it in the same place on the Generation II W126? The one on our 88 300SEL has gone haywire again and we want to simply disconnect it, but not sure how.

Thanks!

Well I went out earlier and didnt see any fuse holder with TWO fuses to remove for the alarm system... anyone have any pics of this?

Thanks.