Hi everyone,

It seems my D1 maintains good running temps so long as I don’t let it idle in traffic. Once that happens temps average 205°-207° F (OBD Fusion App) and the temps never seem to be able to get back down to where they should be until I shut the engine off. If I idle in traffic for an extended period of time my engine temp goes up to 212°F.

Another point of interest is that while hauling a full 5’x8’ Uhaul trailer for a 10 hour drive engine temps stayed below 212°F except when going up extended up hill gradients on the freeway, but this was easily resolved by running the heat in the cab, might this suggest a partially clogged radiator?

What works:
1. 2 brand new auxiliary fan motors
2. A working auxiliary fan switch that engages when engine temps exceed 212°F and stays on for ten minutes after shutoff (auxiliary fans work when A/C is on also)
3. Brand new fan clutch (blowing air in the proper direction)
4. Proper amount of coolant present in the reservoir
5. Functioning reservoir cap - 10 min after engine shutoff you can feel the pressure on the cap and 30 min after shutoff there is a pressure hiss if you unscrew the cap
6. Brand new heater core

What’s old:
1. Thermostat
2. Radiator
3. ....head gasket... (my OBD fusion app shows no missfire codes, there is no white smoke coming out of the tail pipe, last oil change showed a black oil w/ no milky consistency)

Does anyone have any idea? My current opinion is that I may need to recore my radiator, but this is a new problem for me.

Thanks

 

Radiator or water pump would be my first thought. Thermostat is easy to check

 

any checks you can think of to rule out the water pump? I would be seeing coolant on the ground right?

 

What is the outside temp? Those numbers seem totally normal to me.

 

Having experienced very similar temps, I'd guess your radiator needs a re-core.

 

It has been hot with temperatures above 90°F. My main concern is how easily my temp gauge climbs when idling in traffic, I don’t feel like it should be doing that and it should be able to maintain a good operating temp while idling especially now that all three fans are new and functional.

Even on a hot day at startup my temps seem to rise to 187°F and then it’s a slow march up to 205°F which may be an indication of a radiator problem.

Also, I can’t seem to find in the electric manual or the workshop manual what the normal operating temperature for the GEMS V8i engine is so I don’t have any way of knowing if the operating temp is correct.

 

Normal operating temps... stock thermostat is 190F (88C). e-fans energized at 212F. I suppose that is the intended range.

 

Hmm, that’s some solid logic