So I did as little wheeling today in my new to me 2010 H3 Alpha, it was 100° outside temp and I had the ac on full blast the entire time. Driving along it was hot like 210-215, but after sitting a while waiting for my wheeling partner to make it through an obstical, temps rose to 230 to 238. Once I saw that I shifted to low and drove it in first to get rpms up to cool the motor, which it did. What can I do to prevent this from happening again?

Is there a lower temperature fan clutch or more efficient fan I can put on, what about a thermostat? I've heard separating the tyranny cooler from the radiator can help, is there a better radiator out there? What about electric fans? Are they enough to substitute the mechanical setup or would they be better off installed as a pusher to help out? Is one setup better than the other as far as the plug and play offerings. I was running e85, so I don't know if that had anything to do with helping/hurting the temps. Either way, the radiator looks extremely tiny for a v8.

 

Depending on the 4 wheeling you were doing, caked on mud adds weight and also provides an "insulative coating" that holds in heat. Sitting still with the A/C on full blast will rise the temps on most all car engines in general. Not sure why you're running e85, I wouldn't recommend it. Does your owners manual suggest that e85 is an acceptable fuel?

 

Just be sure there is nothing blocking the air flow through the radiator . Then, after your rig cools, remove about 18 ounces of coolant from the system and replace it with 18 ounces of ROYAL PURPLE PURPLE ICE. You will be amazed at the results. Also, it has great anti corrosion properties. And no, I'm not associated with RP in any way.

 

*100 degrees outside and slow speed wheeling or just sitting with the A/C blasting will cause pretty much any vehicles cooling system to overheat. Even more so with a V8 stuffed in the H3s small engine bay.

*A stand alone trans cooler with a fan will do wonders. Removing it from the OEM radiator completely.

*Ron Davis Aluminum Radiator (thicker core) 1-16H3T

*"E85 will make ay engine run hotter. You end up burning as much ethanol as there is O2 in the cylinder which thereby produces 4.4% more heat than octane with even greater cylinder pressures. So while ethanol can burn cooler and produce more power, in reality, you end up burning as much ethanol as possible to get max power. This results in higher cylinder temps than gas (but more power too)."

* I'm about to test out a 160 degree thermostat to see if it make any difference. I don't believe it will but the LS guys swear by them.

 

It's a lh9 engine sp its flex fuel capable. I just bought the h3 Saturday and wanted to run e85 to try it out and clean out the fuel system. I had a ron davis radiator in my h1 and after one season it started to leak all over the place, so I'm in no rush to try them again. Are they the only option for a larger capacity radiator, does it get rid of the factory tranny cooler?

I don't think a lower temp thermostat alone will help in my situation as the clutch/fan can't move enough air over the radiator at idle to cool the motor. That's why I was asking about a different setup.

Anyone try thermal coating on the radiator, I guess it's supposed to help heat transfer up to 1/3?

 

I assume you were reading a scan gauge of some kind to pinpoint those temps?

First 210-215 is NOT hot... especially true when wheeling. You can see more than that towing on the highway.

Next, 230-238 is NOT overheating, although it is on the high side and understandable when wheeling in 100F temps. Did you ever see the "AC OFF" message in the DIC during that wheeling adventure? H3s have three layers of overheat protection, if you never got an AC Off message, all was good. Enjoy the ride.

The H3 will first shut off the A/C if it was on and display "AC OFF" in the DIC; then if temp still rises, display "ENG HOT" in the DIC and chime; then if temp does not fall, go into Reduced Power, all before reaching an actual overheat situation at 260F +.

I run a PCMofNC electric fan conversion, it is loud, but that is because it moves a bunch of air, way more than a clutch fan at wheeling speed. I have a 07 I5, never seen over 226 on the scan gauge, but it does not get to 100 in MI either.

A lower temp T Stat is OK for street driving, not so much for low speed heavy traffic or wheeling. Understand that all it does is shift heat load to the radiator, it never disappears. You are correct in your observation that the H3 radiator is less than robust. I am on my second CSF Racing radiator (first one was a leaker as many others have had... but it was replaced free... ). Do you really want to pack more heat in that OEM radiator in hopes that you will read motor exit coolant temps a few ticks lower? IMHO the lower T Stat move is great for short burst applications, like at a track. Once that heat load gets fully shifted to the radiator, the temps will climb back to high even when measured at motor exit as the system will get maxed out.

Good luck

 

Yeah, Ron Davis is the only option for a larger capacity radiator. It does eliminate the transmission cooler from the radiator.

I also removed the rear rubber hood seal on the windshield cowl plastic. It moves hot air air now out of the engine bay. Fogs up the windshield pretty good in MI during the winter though. So I put in back on in October - March.

 

Over here in the middle east GM added two small electric pusher fans to help cool the H3 alpha. The I5 didnt get those. Those are the same dual fan setup you see on silverados (although not all of them). If I recall correctly there were a 10" and a an 8" fan which are ecu controlled. One runs at 220* and the 2nd runs at 228*.
Anyway, I never really kept track of my temps before but it never went above half. The needle was always below and according to my obd2 reader, at 228* the needle moves to exactly half, it will stay there up to 240* (maybe more but I dont want to find out)

 

That just seems too hot to me, I'd prefer it to run right around 200 or just below. Are these fans just aftermarket or is there a factory part number?

 

They are stock but I dont have a part number. I would recommend you buy a Spal pusher fan in a 16" size as that would do better than the dual setup and probably be same price. If you have access to a tuner you can hook the fan switch directly to the ecu and have it come on automatically at a set coolant temp / ac pressure
The GM oem fans are spal btw. Just get the long live (LL) version.