Hello I am new to the forum. I have OM602 from 1992 Mercedes 300D.
I will be doing swap into a 4x4 truck. Can anybody tell me where the thinner pipe on the thermostat housing should be connected to.

I need help with identifying the water connection marked E on the picture.
The two other lines are going to fuel heater, so where is the third pipe marked E going to. I will be swapping the engine into 4x4 truck.

Those would be the heater core in/out pipes

__________________
97 e300d, 78 300Dt, 95 E300d, 94 E320 estate