Coolant flow direction on 85 300TD?
 

Does anyone know the flow circuit of the coolant lines throughout the engine?

I have an Espar coolant pre-heater in our car, (have been using it to start the car in remote and very cold places and also to help decrease switch-over time for a WVO system).

I was only recently told that its OK to continue to run the heater even after the engine is running to speed up the coolant heating as you drive. However the pre-heater should be pumping the coolant in the same direction as the engine.

Im assuming the coolant enters into the passenger side of the engine and comes out the top part of the drivers side? but I really dont know. Any diagrams that can show this?

I may like to rework the way the coolant lines for both the pre-heater as well as the WVO system are tapped in to make the circulation more efficient, and clean things up. Currently theres heather hose like spaghetti all over, and one annoying one tee'd in just above my oil filter so as to force me to have to disconnect the heater hose to change my filter. A real drag, especially with a hot engine! It wasnt me that did it...

Thanks.

If I was hooking one up for normal use when the engine isn't going, I'd put tees in the heater hoses right where the return goes into the water pump by the alternator, and where the heater line comes out of the head by the oil filter housing. Thing is by putting the coolant heater output into the head (where it should be, as the head should be warmed first) is the wrong place for when the engine is running, because as you say the flow is reversed once the engine water pump is spinning.

Not sure what the best option is, sounds like you're rather pressed for spare space as it is :P

Google 617/20-005.pdf Benzworld.org has a diagram. Yep, put it at the water pump inlet as NZScott suggests. That way, you heat the block by circulating coolant via the bypass circuit till the thermostat opens.

Thats a great diagram. Just what I was looking for. I think its best to keep the tees where they were originally put, which is same as you suggested. (but perhaps moving the one above my oil filter a little for better access)

I have an extra coolant pump just under the reservoir. This isnt on the diagram. Not sure what its purpose is if theres already a coolant pump connected to the engine.

Also in the diagram there a "Regulating Valve For vehicle heater" anyone know how this can be adjusted? Im wondering if It can be used to help heat teh cabin a little better. When stopped and idling, the heat goes way down on especially cold days. However I wouldnt want to take away too much heat so as to compromise the heat to where it should be for smooth running (on WVO)