What coolant temp are you guys seeing on you scan gauges, i'm seeing 160 to 170 and it cools rather quickly. i'm wondering if i have a stuck open t-stat. But this is an infered temp from the cylinder head temp sensor.

 

Mark, I don't monitor my coolant much but when I check my trip information, the Max is always around 181F on most days. You might want to go out and check the current trip data for that reading and compare to my max average.

GaryG

 

one of the reason i'm concerned is I have noticed that I get better mileage after I have driven on the highway for an hour. I have seen MANY t-stat that open early or are stuck open.

 

I keep this on the SG display, and see 181-184 F on the freeway. It varies slightly with load.

 

I monitor the coolant temp all the time. While under load I will see approx 180F. While on EV going down a long hill, especially in cold air, it gets down to approx 160F. I don't think this is unusual. I mean, the engine is stopped and no heat is being generated by it. And the engine and its compartment are not insulated. And as you state, mine cools rather quickly too.

 

FWIW, every Ford I ever owned ran "cold" IMO.(86 Taurus, 87 E-150 Van, 94 Explorer, 99 Expedition, 85 F-150). The others were non-hybrid of course--but methinks it is a Ford trademark (maybe extra cautious to avoid overheats?) GM vehicles didn't seem to run that cold to me...

Nate

 

If you turn your climate control to the off position in EV, the electric coolant pump remains off and will not circulate coolant. This will help keep the engine warm till you get a restart. When the engine starts, the belt driven pump will start circulating coolant again. The reason you have an electrical coolant pump is for use of the heater in EV. The electric pump will run in EV unless the switch is in any position but off.

GaryG

 

I have no technical docs so I'm curious....Is there only one electric coolant pump Gary? How are the electronics being cooled if the pump is shut off and there is only one? I suppose it might be that they only need to be cooled when the power converters are running and as long as no energy is being sent to the 330V system and the 12V system can run off its own battery cooling might not be necessary.

 

Tim, there are two electric coolant pumps, one for the electronics and one for the heater when your in EV. These are to separate coolant systems. The electronics coolant pump is larger and is located on the right near the bottom of the radiator. The smaller heater pump is located on the left (drivers side) and near the bottom of the radiator. The belt driven coolant pump of course stops when the engine stops. The electric heater pump then starts and circulates coolant for cabin heat if the HVAC system is on.

Be aware that the Hybrid Tech told me he has been getting a number of FEH's that the heater pump goes bad at around 50,000 miles and is not covered by the 36,000 mile/36mo warranty. I stopped using the climate control vent to save energy, but now that I know the pump goes bad so fast, I feel even better knowing how things work.

GaryG

 

well mine must be normal, though I'm used to seeing 190 to 230 on most Ice engines, but this is inferred not actual, unless Ford uses a 160 deg t-stat in the hybrid. Also the miller cycle engines like diesels don't heat quickly.