I recently purchased a 2008 Hummer H3 Base 139K Miles.

It has a number of issues, but so far nothing too serious. It generally runs and drives fairly nicely. I've already fixed a few minor issues.

I'm in Florida, and it's been over 90 deg F every time I've driven the truck. I've noticed that the temperature gauge creeps up at Red lights and the A/C does not blow as cold. When I start moving, the AC blows cold, and the temp returns to the center mark.

I spun the fan, and I would say it fails the clutch test. There is no fan roar when the car is cold and you rev the engine (or at any time).

The previous owner told me that he recently replaced the radiator. He did not replace the Fan Clutch/Water pump at that time.

I have previous experience with a Vortec 4200 (Trailblazer) that used to eat fan clutches for breakfast, lunch and dinner. I think at least one was replaced on a recall.

I'm thinking of buying an aftermarket aluminum 3 tube radiator with shroud and electric fan, but since the radiator is nearly brand new, I'd hate to pull it and take it to the recycler. I'm thinking of feeding it one fan clutch and seeing how long it lasts.

Recommendations? Has anybody tried a radiator/electric fan as I described?

Other questions:

• 36mm on the FC nut -- Right?
• Left hand thread on all H3 FC's?

Thanks for help/opinions.

 

Get a fan clutch specific to the H3. If the I5 is like my Alpha, the fan clutch nut is not as deep as you may find in other more generic clutches. I spent a week last summer trying to remove a non-H3 specific fan clutch that someone before me had "made work" on the truck. Grrrrr.

I put a Hayden severe duty clutch on my truck (along with new water pump, thermostat, tensioner, idler and belt) and my truck runs much cooler now. When temperatures start to creep up because I'm moving slowly I get the revs up by idling around 2k in neutral or running in a lower gear and the temps return to normal. I also installed a scan guage so I can monitor actual coolant temperature in real time. The only downside of the severe duty clutch is that it can be louder, but thats because its working.

https://www.rockauto.com/en/moreinfo...t=6812&jsn=400

 

I ran one of the early PCMofNC Efan conversions on my 07 for many years, it worked perfectly but its single large fan was loud when on. Not really too bad since in MI there are months the temp is low enough it never needed to run. I still have it for a back up just in case. They have made a couple improvements, like shroud flappers to let driving air through a greater space than the old shroud panel did. I bought some flappers and am prepared to cut them some spots to install if needed.

On my 09 Alpha I installed a SuperModulation Sfan4500 with digital controller. Much more quite that the PCMofNC Efan as the Sfan 4500 has two fans in a plastic shroud spinning opposite directions and the controller ramps up the speed as heat requires and can run at a lower RPM to maintain water temp without the howl. Been perfect for the last two summers and the start of this one. I would do it again.

 

Thanks for the replies.

I used my H3 to two my boat on Saturday. While the temp gauge did move around some (I was briefly in a little stop-and-go traffic) it never hinted at actually over heating.

I actually ended up pulling the boat out twice (it wasn't on the trailer correctly the first time) and each time the H3 pulled it out with absolutely no struggle at all (in 4WD Lock Low). In the hot weather, and in Low, I did hear fan roar (not just rev'ing engine) as I pulled away from the ramp, so I'm thinking that I'm at least OK for now.

I followed the link that @NMH3 provided, and it said it was the last one, and only $29 wholesaler closeout for the super duty clutch -- I couldn't loose, so I went for it. If/when I get more indications of it really needing a fan clutch, I'll have the super duty one on hand.

Thanks again!

 

Keep in mind you should not use lock (high or low) on dry pavement so as soon as you get up the ramp, switch back to Hi.

 

The ramp I use is very shallow. There is cement in some places and not others. Where there is cement, it's covered with sand. It's more like launching off the beach.

I drove straight forward a bit before removing the plug and taking loose items from the boat because it was really busy.

I definitely put it back in "normal" 4WD mode before we drove off.

I use this ramp because I was previously towing the boat with my vintage Chevy 1 ton (C30) truck. It's a manual transmission, (2WD, with granny gear) and it has no parking brake. This ramp is so shallow and has deep enough sand that I would occasionally leave the truck in neutral on the ramp. It would sit fine in the ruts left by myself and others spinning their wheels pulling boats out. -- I always made sure I had plenty of margin against it rolling, but I realized that all it would take was a moment of lack of attention, or perhaps something like a large wake moving the boat, and I'd end up in a "Googan" video. Of course I also didn't like throwing wet, salty sand inside my wheel wells, or putting wet, salty life jackets (or people) in the vintage truck. These were all reasons for my purchase of the H3.

The H3 has both park and good parking brake and it pulls the boat out without a hint of wheel spin. I really only put it in 4WD Low/Lock because I could. I'm pretty sure I didn't need to.