07 H3 losing coolant?

[Bro]

Hello All,

I recently had my 2007 H3 in for servicing because I noticed it was losing coolant from the reservoir tank. The tank would go bone dry in about 4-6 weeks of driving the vehicle. The dealer stated they saw no external leakage and I''ve noticed nothing in my home garage or parking spaces at work. They stated through their testing that the coolant isn''t going back into the transmission so they went ahead and replaced the head gasket. It was a hit or miss job they admitted! Well, the truck is still losing coolant and has 29K miles on the odometer. Would the Dex-Cool be evaporating somehow? Or could there possibly be a crack in the head or engine block? There should be external signs of leaking if that was the case, correct? I thought head problems only existed on the 06''s? I have yet to get a check engine light or overheating. On hot summer days the truck did run about 3/4 on the temperature gauge though. Any help would be greatly appreciated!



Thanks

[07Humvee3]

By any chance did you check your engine oil? if there is a crack in the head or engine block, usually water gets into the oil...

[wpage]

Had that problem initially with my H3 losing coolant. Started adding straight unmixed coolant (not 50/50 mix) and after a few fills it stopped....

[Bro]

Well, it was the head gasket on my 07 H3. They replaced it and I am no longer experiencing a loss of coolant. They said it's growing to be an issue on the 07's so keep a look out.

[pdsq99f4]

We've seen a few 07's with trans coolers leaking it into the transmissions. It's hard to see it in the trans fluid sometimes unless you put it on white paper.

[Bro]

Hello,

after they replaced the head gasket, the actual head itself and a few other items. The culprit was my trans cooler leaking internal to the radiator? Does that make sense? :popcorn: So I got a new cylinder head, radiator, coolant flush and overflow tank out of the deal. They replaced the cylinder head after stating cylinder #4 had excessive leak down.