MB 420 SE 1993 W140

[MBfreak]

A family car with about 150.000 miles on it. Over the years we have maintained it , has a nice hobby shop.
The most irritating problems:
Ignition module died. Engine also has poor quality distributor caps, they die every fourth year.
2021 we replaced all suspension bushings, shocks and springs. Normal old age stuff.
Car has a fancy radio/CD and a 7 channel amp (BOSE). The BOSE amp had problems, absolutely impossible to find schematic. Problem was caused by a poorly designed PCB. Now repaired. Made in Taiwan, and has a MB 10 digit part number. Avaiable from Stuttgart, only $3300.
A year ago car started giving high CO and HC. EGR valve pneumatic actuator had a leaking membrane. Repaired.
Idling was a bit off. WE sent the 8 injectors for ultrasound cleaning and test. After ultrasound , perfect spray patterns and less than 2 % volume spread.
Still some high exhaust values, will send the two catalysators for test and cleaning.

The W140 is, according to our opinion, the last MB that does not look like a hippo.
Even MB has realized this and rumour has it that the 2025 SE will look nice.
May MB not stick a V6 in it and call it 350 SE


Ola

 

[Steve from Socal]

1993 was in the years with bad wire insulation, has the engine wire harness been checked/changed? The W140 and R129 were the last MB's designed before the bean counters took over!

 

[MBfreak]

Steve ,
We were harness lucky. Just had to renew a small part of the engine harness to the MAF

The W140 has a load of component rich subassys. And most of them are complex but repairable.
Worst offenders;
Boot lid lock assembly
Reverse "antennas " on the rear wings
Hoses, couplings and central unit ( lives in the boot) for the soft close system
Rear view mirror with auto tilt.

A person at the MB Old Timer Center I talked with said that the "hippo designs" of newer MB´s
are to sell the car in Asia. And I guess he is right. Another mfr is RR. Their 2015-2023 cars are even worse.

Luckily , the cabriolets from both mfr are still nice.

Ola