Have an 05 gmc 2500 hd duramax i'm working on for a coolant loss problem for a friend. Level goes down enough after a week to make the low coolant light come on. Pressure tested the cooling system for 45 minutes. Did not drop a pound. Added coolant dye and ran vehicle. There is no visible leaks. After driving truck for a while, the upper rad hose is rock hard. Also the temperature gauge goes from half to 1/4 and keeps fluctuating. Performed a hydrocarbon test on the cooling system and none were found. The truck only has 95000km. It went into the dealer yesterday for this issue and was told there is nothing abnormal. From all the tests i performed, i have come to the conclusion of a head/gasket problem. How do you go about getting the dealer to resolve this problem? Any assistance or comments would be greatly appreciated. Does everybody here think this is a head gasket issue?

Possibly EGR leaking coolant into intake tract and getting burned off.Happened to my buddies 05 LLY and several others as well.Pull EGR motor for a quick visual.

Mine was losing coolant just like yours and none of it wound up on the garage floor. The water pump leaked but when the truck was moving it would just blow into mist by the fan. Stopped, it would run down the hose and dripp onto that black plastic pan below. Then moving again, anything on the pan would also blow away. Take that pan off and check the radiator hose and everything around the water pump for wetness. If you're lucky you'll find some. Drive it for a day or two without the pan and keep watch for drips when you're stopped.

hard radiator hose:eek: head gaskets. sorry dude. testing the coolant with a block tester on these is not really worth it. it doesn't work. the temp fluctuating is from air in the system. don't drive it until you get it fixed as the temp gauge is not accurate and you probably are running temps much higher. good luck

Have an 05 gmc 2500 hd duramax i'm working on for a coolant loss problem for a friend. Level goes down enough after a week to make the low coolant light come on. Pressure tested the cooling system for 45 minutes. Did not drop a pound. Added coolant dye and ran vehicle. There is no visible leaks. After driving truck for a while, the upper rad hose is rock hard. Also the temperature gauge goes from half to 1/4 and keeps fluctuating. Performed a hydrocarbon test on the cooling system and none were found. The truck only has 95000km. It went into the dealer yesterday for this issue and was told there is nothing abnormal. From all the tests i performed, i have come to the conclusion of a head/gasket problem. How do you go about getting the dealer to resolve this problem? Any assistance or comments would be greatly appreciated. Does everybody here think this is a head gasket issue?


i had the same exact problem on my truck dealer couldn't find anything either took it to them 3 times and they finally decided to change my head gaskets and hasn't leaked a drop since then. 75000 hard!!! miles:D

Yep, hard upper hose after cool down would be head gasket.

How do you get the dealership to do something about the problem?

I just finished replacing the engine in my truck due to a head gasket issue. Same symptoms as yours. Low coolant light would come on after a few days. No visible leaks anywhere. Got much worse after the MPI install.;) When we pulled the engine, the leak was visible in the valley coming from the passenger side head. It got so bad that I could relieve all of the pressure in the coolant system, drive 5 miles with almost no boost, and the upper hose was rock hard.