My MB 1991 420 SEL has 220,000 miles cranks on ignition does not start. What should I do?

Asked by Jul 25, 2014 at 03:43 AM about the Mercedes-Benz 420-Class

Question type: Maintenance & Repair

My MB mechanic said that our 1991 MB 420 SEL needs new ignition control unit. The
cost is $920 for part and $172 labor. It also has an air pump that is seized. The
mechanic said it will cost additional $600.00 for the pump and the labor. Is this a
reasonable analysis of the problem and the cost of parts and labor from other 1991 MB
420 SEL users? I live in Seal Beach area in Southern California. Any good mechanics
you can give names with phone numbers please. I like the car. However, it is costing
more and more. Last year, I spent 1200 to rebuilt the transmission on this car at . I
also spent $560 for an alternator last week on this car. Is it worth keeping the car or
sell or donate and get another used car? I do not know what to buy in MB used

9 Answers


Go look on EBay. When I was in the States I sold the ignition control boxes for $50.00 to $75.00. If it's what I am thinking of it bolts to the driver's side front iner fender. It's a 10 minute job. As for the air pump, thats also a ebay item. No more than,$100.00. But it's a PIA job. If you're handy go to a recycling center ( AKA junkyard ) and pull it yourself. If you have a Pick and Pull in your neighborhood they will pull it for you for a fee. Don't get ripped off! BTW any half assed Craigslist mechanic can do the job. Let me know. If I was back in the USA I'd be making you a deal.

1 people found this helpful.

P.S. bullet proof cars. Loved mine.


I just googled "W126 Ignition control box" and it's just as I thought. If memory serves me correctly its 3 10MM bolts that hold it on. $170.00 labor? More like $10.00. It's probably the easiest DYS job on your Mercedes you can do!!!! FYI your Mercedes is a W126 model. There were many different motors put in that body. Off hand I recall 5 different gas & 2 diesel engines in the US imports . So here is what is key in getting the right one. W126 (that's the body style) 420 (that's the engine) same thing for the air pump. Let me know if I can be of any more help. I had a 560SEL that was a fantastic automobile.

1 people found this helpful.

ok- you have an old Benz with a lot of miles- and you are worried about spending too much money?! Do you see the disconnect here?


Hi Jamn. I feel for the guy. Those old W126's......... Well it hard to explain. They are just so darn reliable, comfortable and for the most part easy to work on. That was also the last mass produced Mercedes that was for the most part hand assembled. 1991 was the last year the W126 was imported into the US. I've seen some later years of them here in the Philippines. So please give em a little understanding.

1 people found this helpful.

lol- I agree, Mr. Mark- the old iron is the best- but only practical if you can work on it yourself, or if you have a lot of disposable income- $$$


Yeah J.B. I have a 1195 450SL back in the states that I am dieing to get over here. It's a matter of......... shall we say, time.

check w

Had my 1990 420 sel 7 years now, the most reliable car I ever owned, but do all repairs myself, im not a mechanic, so easy to work on, Hears the golden rule, replace all the low cost items first, (like a fuse) your problem I believe is the Ignition coil, new about $65,00 location on the drivers side inside fender just below the ABS box, two bolts and a ground wire, PS you got ripped off. Your mech full of B/S

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