Overheating - Help!
 

Hello fellow Benzies,
After Removing my injection pump to fix oil leaks, I find that my car is overheating after running awhile.
Main fan is only spinning at belt speed. With air conditioning on, the small front fan is not coming on.
Does the car have another problem or could it be related to my injection pump R & R.

Thanks fellows.
1987 300TDT 170,000 Miles

Is the car overheating at idle or while driving and just how hot is it getting?
The main fan should be spinning as fast as it can at around 95-100C. There will be a noticeable difference in airflow, especially when the engine is revved if it is working properly. If not, the fan clutch needs to be replaced.

As far as the auxiliary fan, it should come on at low speed with the air conditioner on when the air co pressure gets to a certain limit. The fan should come on high when the coolant temp hits 107C.

My guess is that when fooling around under the hood you knocked a connector loose or broke a wire to the aux fan. All the wiring is designed to be reliefed against vibration, not hands.

I was wondering about the pump timing. Gassers get hot if its wrong, diesels might too.