Improving Forged Engine Longevity w. Coolant Pre-heaters (i.e. Webasto, Eberspächer)

[Enlight]

The only problem I can see with your plan is the radiator will cool down the coolant that's returning to the heater. I would cut the radiator out of the loop for maximum heating of the engine.

I'm seeing coolant temps hit 219f and I suspect that it's because coolant is bypassing the radiator through the pre-heater. I thought the pre-heater lines would be sufficiently small that it would be insignificant, but after burping my coolant system the temperatures are still high. This wasn't so much of a problem in the winter.

I thought about installing a "reverse" inline thermostat (open when cold, closed when hot) on the pre-heater supply line but I don't think such a thing exists. I think I will just go back to my original plan of supplying from the bottom radiator hose. I could also tap the turbo's coolant line but that's a long length of line to run.

 

[PoorMans180SX]

Trends look good and low.

 

[oil pan 4]

Thank you. Between the wiring, finding a location for the heater, and drilling a hole in the tank I'm dreading the install a little bit. I've also got a rough idle right now and hope I don't have to tear apart the entire fueling system to figure it out. The car has a Fluidampr and I dynamically balanced the flywheel. It should be a lot smoother.





I did consider the oil pan heater as well and I'm not ruling it out completely. In the interim, I might try pointing the exhaust of the coolant heater towards the oil pan to see whether that makes a difference. IIRC, the EJ25 did not have coolant plugs on either side of the boxer engine, the one I installed was somewhere in the bottom-middle towards the driver side. I also didn't want to have to worry about tripping any breakers as I use this car for road trips. The current freeze plug was actually just a holdover for until I figured out the Eberspaecher.

If one had to choose between a block or oil pan heater, it looks like the block heater would do a better job of closing up pre-start tolerances and helping atomization/cold starts. Here's a YouTube video on the topic:

There was an early, obscure or test version of a hmmvw artic cold weather package that used an oil pan with a void that took hydronic coolant heater exhaust gas and used it to warm the bottom of the oil pan. I found these oil pans for sale on ebay. This was probably back around 2006. It seemed cool but I didn't have a use for one on my 6.5L diesel.

 

[Enlight]

There was an early, obscure or test version of a hmmvw artic cold weather package that used an oil pan with a void that took hydronic coolant heater exhaust gas and used it to warm the bottom of the oil pan. I found these oil pans for sale on ebay. This was probably back around 2006. It seemed cool but I didn't have a use for one on my 6.5L diesel.

That sounds pretty cool. Now that it's summer, I often see that the oil temp is already 100f before I crank the engine - I forget what it was in the winter. Besides having the exhaust pointed just below my oil pan, my car came with a coolant-oil heat exchange.