I intalled a fail safe thermostat in a crew cab dually I had and it failed the first time it got warm. It did fail in the open posistion but I wont use another one. I would just pull the t-stat out for the summer and see how it goes. That way you will know for sure that the t-stat is not causing your problem.

 

Not always... I blew the head gasket on my Exploder and drove it 30,000 miles adding a gallon of coolant every couple of months.... and there wasn't a drop of coolant on the ground... no smell....

 

Is there a downside to taking the thermostat completely out for the summer? Like the computer getting wrong signals etc? what would the normal operating temp be with no thermostat?

 

Part of the point of having a thermostat is to keep the coolant in the radiator to cool... and to keep the engine at perferred operating temps... I would only remove it to troubleshoot and isolate componets.

Are you sure the system is bled?

Are you sure the Thermostat you have in there is good? Do you want to boil it and see if it pops?

Are you sure your radiator cap is good? What about your reservior bottle?

 

good point Muddy

 

You need to find the problem... adding fans is once again puttingbandaid on a hatchet wound...

So.. any updates?

 

We currently don't have the fan shroud on. Would putting it on be a benefit? The choice we have right now is to put it on, or leave it off and add 2 aux electric fans on each side of the regular stock fan. If we put the shroud on there isnt room for the 2 extra fans. What do you think is best?

I don't know what the problem is... We had it at the hummer dealer last year and they couldn't duplicate the problem, it only does it once in a while and isnt leaking coolant that is noticble. So we're fixing things that could be the problem that arent stupid money, new thermostat, I think we're going to try and get a 180 fail safe tstat. Coolant flush with between 30/70 and 40/60 dexcool / water mixture, then adding water wetter in. Adding aux fans in front of the radiators / tranny coolers, this was what most people thought the heat would be coming from, the radiator and stock fan are brand new as of last fall. 2 more fans inside engine compartment plus stock fan.

Thanks in advance!

 

Thanks guys for the help so far!

I think the biggest factor might have been we didnt have a fan shroud. We we bought it from the previous company with around 40k miles the fan shroud was all cut up because they put aux fans on. When we replaced the stock fan last year we never put it back on. So we put the fan shroud on.

Also we did a full coolant flush with about 30/70 dexcool/water with water wetter.
Also we added aux fan in front of front radiator / tranny cooler, which we have on some of our other hummers. I would suggest this to some of you guys that are worried about tranny temp before spending alot of money changing radiators etc, this is a much more cost effective setup.

The limo did go out on a 2 hour school luncheon today and its 80 degrees outside total amount of time was about 4 hours running, and never budged past 195.

 

oh yeah.... good thoughts on the shroud.... that's like putting a box fan a box fan a foot from the window...

Glad it all seemed to work for you so far....