M111.921 engine reliability

[sechs]

Hey Mercedes gurus!

I´m looking for some info about the reliability of the M111 engine. I´m about to buy a 1997 S202 auto with this engine and it has 120000 miles.

What are the most important aspects to be aware of?

Thanks guys

 

[Nasco12]

So long as they have been looked after, with the oil and coolant changed regularly, Mercedes engines of this period are pretty reliable. Many go on for 250-300,000 miles.

Things that can go include MAFs - sluggish acceleration and Crank Position Sensors - cutting out when hot.

Occasionally, the head gasket will fail - as it did on mine. The only way I would have ever spotted it would have been to have got the car on a ramp and to have inspected the bell-housing which is where the coolant would have ended up.

 

[grober]

Very reliable engines. Look out for problems with the HT ignition wiring to the coils and the HT LEADS/EXTENDERS-- they can get cooked inside that plate over the valve train cover- usually revealed as a slight misfire when warm or cold-- nothing major otherwise. Later W202's have their engine ECU'S coded to the ignition as a security measure so cannot be easily swapped.

 

[sherco450]

Hey Mercedes gurus!

I´m looking for some info about the reliability of the M111 engine. I´m about to buy a 1997 S202 auto with this engine and it has 120000 miles.

What are the most important aspects to be aware of?

Thanks guys

l had the same engine in my 1998 vito 113 petrol manual . l changed oil every 8000 km ran it on 95 ron and sold it with 428,000 .no major problems,