E220 -95 engine dip & rush when put into gear

[MarkusBergstrom]

Hi

I am new to this fantastic forum.

I have a few issues with my E220 -95 estate automatic:

1. It overheats slightly and the radiator liquid overflows in summer time.
2. At stand still, and when put into gear, the engine can drop and then compensate by rushing.

I have the feeling that the two issues might be connected. I thought it might be some kind of sensor issue so I bought the Mercedes W124 1985-1995 Owners Workshop Manual. I love the manual and the help it provides for smaller repair tasks but the issues described above are too complex to troubleshoot. If anyone could put me off in the right direction I would be very thankful!

Best,
Markus

 

[Ian B Walker]

No2 will be down to one of the following.

The throttle body needs cleaning (done by wiping the inside of the butterfly with brake cleaner on a lint free cloth)

One of the springs on the throttle linkage is either missing or snapped (there are 2 springs)

The throttle body itself is at fault (could need bootstrapping or renewing, about £80 from a breakers)

 

[grober]

1. may be down to a faulty viscous coupling on the engine cooling fan. This would be more noticeable in traffic or stop start motoring in warm weather- on the open road much of the cooling flow through the radiator is due to a ram air effect due to the car moving forward. You may also have a supplementary electric fan/s in front of the radiator if the car has aircon. These are again designed to cut in to help cooling in hot weather. They can seize up or their controlling circuitry cab fail.---- try to keep an eye on the temperature gauge.

 

[MarkusBergstrom]

Thanks Ian! I will look at the throttle body and the linkage and start my search there.

 

[MarkusBergstrom]

Thanks Grober! Do you think a faulting water pump or temperature sensor can be ruled out? I will look into the fans (both) to start with.

 

[kth286]

if we knew where you were based perhaps someone local could help.

 

[grober]

Thanks Grober! Do you think a faulting water pump or temperature sensor can be ruled out? I will look into the fans (both) to start with.

The fact you are experiencing coolant loss only in the summer time points to overheating rather than a water pump leak. The viscous coupling clutch on the fan relies on a bimetal strip on the hub to govern its on off operation. It sometimes worth giving these a GENTLE!!clean with a old tooth brush and WD40 as they can accumulate road dirt.