Thanks for the update. please keep us posted

 

I'm reporting what I am observing that it seems to take a little longer to heat up. I have an 06 with the 180 F tstat that probably starts to open about 175 ish. I have a concern with delaying the torque converter lockup and perhaps the oil not getting hot enough to boil off any water vapor.

My guess is that the 4 bladed fan lets more air through the radiator when you are moving. This cools the coolant in the radiator better and the extra air flows across the engine to remove more heat. Many vehicles with electric fans turn off the fans when the vehicle is moving above a certain speed because the air being forced in through the radiator is sufficient. Perhaps the 8 bladed fan actually restricts the air flow when you are moving.

I'm

 

Tom,

I was thinking about the possibility of a stuck open tstat after you mentioned it. I let it idle from cold and monitored the ECT. I saw an increase in ECT until 175ish F then it started leveling off. I'm guessing that is when the tstat started opening.

I was thinking about the other stuff I had done to the H3 if that would influence the engine temps and here is my off-the-cuff list:

1) I removed the hood seal - this lets more air pass by the engine.
2) My cold air intake gets all of its air from the front of the grill - so no sucking in hot engine compartment temperatures.
3) I've been doing my own tuning for a while concentrating on both fuel economy and power. My city MPG is over 16, and for a comparison my son's Cadillac CTS is just over 16 MPG in the same area. So my efficiency is up and my residual heat is down placing less load on the cooling system. For example, I enhanced the stock DFCO (deceleration fuel cut off) setting so that when I let off the gas the engine kills fuel even with city driving, and I think I optimized the tranny shifting/torque converter lockup to improved MPG.

 

What "hood seal" are you referring to? The one at the front on the underside of the hood, or the one on the truck just in front of the windshield?

The front one is there to try to force more air through the radiator instead of letting it get over the top. That one is important.

 

I think it is better thermodynamically to run the engine hotter because more heat from the combustion goes into doing work instead of the heat going into the block.

 

In the summer, I remove the hood seal near the windshield. I put the hood seal back in for the winter. I haven't had any issues with water.

 

I put the hood seal back in. It heated up a little faster and the engine temps increased by maybe 3 to 4 F.

 

I gained about 0.4 MPG so far. I need more data to be sure of the improvement.

I think I'm going to adjust the tstat to open at 185F instead of the 175ish now.

 

if you're changing it,i guess, id like to hear about the job. messy im guessing.
oh,i surprised the temp changed with the seal. i thought the tstat would hold it.

 

I thought the typical cooling system only removes about 30% of the engine heat.

Removing the Tstat is going to be messy and the location makes it worse. Maybe it would be a good time to replace the coolant too.