1990 Mercedes-Benz 420SEL Questions

Get answers to questions about your 1990 Mercedes-Benz 420SEL at RepairPal. Find solutions, diagnose problems and get back on the road.

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My battery keeps running down due to constant static coming from radio car doesn't need to be started nor does key need to be in the ignition and radio is able to be turned on is this normal? ????

The problem just started but I notice for a few years when I first accelerate, it would race while shifting, but I thought that was only normal. How can you help by offering a diagnosis.

I have replaced the climate control switches, a/c compressor, mono valve, thermostat, I need help and or cost for repairs

I know that the ezl module controls the advanceing and retarding of the ignition not able to adjust the timing

which rims are better alloy or chrome plated?

dashboard gauges not working

The economy needle has gone from black all the way to red.

The car is locked and also the trunk and front of the car. Even still the alarm goes of at random times when the car is locked. How can i fix this issue?

as soon as the car run the abs ligth in the dash goes on. in reverse the car don't do that

This is the second set of injectors, 68k original car miles. How do I select new injectors that won't leak-down?

Note: At 1500rpm if the front injector fuel lines are broken loose air escapes and upon retightening the car runs smooth firing on all cylinders.

It looks like the clutch assembly failed, shifted, spewed oil, caught fire when grinding against a fitting. What do I need to concern myself with when replacing?

Can't get new relay to snap into the mating 10 pin assembly. Can't get the two notches on the relay inside the plastic holder.Do I need to remove the entire plastic holder (which houses 3 relays)? One of the 2 nuts securing the plastic holder to firewall has zero clearance! Help would be greatly appreciated.