New Owner '86 420SEL
 

Hi, I'm new to the group and last night facilitated the purchase of an '86 420SEL for my 18 year old step-son. It's in great shape, the interior is like brand new, has 120,000 miles and so far I've been unable to contact the previous owner to get the history (but I'm still working on it). There are a couple of little things I'd like to fix up and figure out so I need a little help.

I did a search on the VIN through a website (can't remember what one) and it comes back saying the car was a Diesel. Anybody know where I can find out for sure if this is true and I've just bought a body shop special?

There was no owner's manual in the car so trying to figure out the knobs and controls is a little cryptic. Does anyone have a manual they might be able to scan and email?

Power locks all work properly except for the driver's door. It doesn't lock or unlock any other door.

Passenger seat recline works fine going down but you have to hold your mouth just right to get it back up. So far, neither my s-son or myself have been able to find the sweet spot, only the lot boy was able to.

Any other suggestions regarding keeping the car looking and running well with as little expense?

I'd appreciate any input and thank you in advance.

Geno.

The VIN should begin with WDBCA42 or 43. If the 5th position has an A, it's a gasser; if it's a B, it's a Diesel. Don't put too much stock in what some lackey keyed into an on-line system. You might get a vehicle master inquiry (VMI) from any MB dealer and have them check that the VIN belongs to the car.

You can get an owner's manual from MB for something like $10. Some claim to have gotten complimentary copies. You can also check eBay. If you get the MB repair and maintenance CD set for that car (the one published by MB and available through the FastLane link at the top of this page), there's an owner's manual in PDF form in one of the CDs.

Door locks could be a bad switch in the door handle assembly. You'll need a wiring diagram to diagnose the problem.

Seat adjustment could be dirty switch contacts. Spray contact cleaner (e.g., Caig Deoxit) into the switch.

It's a day late and a dollar short but find a reputable independent MB shop and pay $100-150 for a prepurchase inspection. That will tell you where you stand and what needs immediate attention.

Sixto
95 S420
87 300SDL

Well, we've got a few of the right letters....

WDBCA35D4GA......

I was guessing. I checked eBay and all the 420SELs at auction have WDBCA35 prefixes in the VIN.

Sixto
95 S420
87 300SDL

Thanks for checking, I feel _much_ better now!

M116's are famous for breaking timing chains at around 100k. If it hasn't been done already I would change it right away. Listen for a rattle on start up as the oil pressure builds. Not to bad of a diy job.

Thanks for that info. I'll listen more closely next time I hear the car start. I don't recall hearing anything. I did hear a funny noise on startup of a 300E we were looking at though.

The car feels a little mushy on the shift from 1st to 2nd, is that normal?

It's peculiar because the 420SEL starts off in second. You have to really mash the pedal from a dead stop to engage first or start off with the shifter in 2 (or B). Then you'll feel three upshifts.

As to the mushiness, could be a sign of big trouble or the transmission vacuum modulator on the left side of the transmission housing could use a tweak. These transmissions are sophisticated but you can try this - remove the black rubber cap over the center of the modulator, pull out the T handle enough to turn it, give the T handle an eighth turn clockwise, push in the T handle, put back the rubber cap, test. Does that firm up the shifts? The proper way to set the modulator is with transmission pressure gauges so don't go nuts with adjustments.

Sixto
95 S420
87 300SDL

I imagine the site you looked at was a W126 (Mercedes Benz W126 Club?) site. My car is a '90 420sel and it came up a diesel on that site also. Must be a glich.
As posted previous, if the timing chain has not been changed, change it. If not you will be facing an expensive engine rebuild or replace if it "jumps time".