i have a 06 explorer with the 4.0 V6. 4x4 XLT with 106xxx miles. i just bought this thing back in january. of corse i didnt get an ext warrenty. well the past couple months its been loosing power, its got a stumble and seems slugish. its loosing water. no water in oil, no oil in water, dont smell coolent in exhaust. yesterday i went out and looked and found at front of head on pass side at front cyl, there was coolant from head gasket down the block and also in the valley of the block. i started the engine and once warm, everything was dry. shut it off after about 20 minutes and still nothing wet. this afternoon the only wet spot was in the valley which was dry after running yesterday. is there anything else i can check before tearing it down? with the water in the valley it looks like it could be comeing from thermo housing. thanks for any input.

 

Pressure test the cooling system... dont guess!... Philip

 

how can i pressur test it. can you get a kit from parts store?

 

Thermo housing is a suspect before head gaskets on this motor.

This is a kit for $100--how often will you be using this baby?

Radiator Pressure Tester Kit

Of course, the heat of the engine will pressurize it for you, and if you are lucky, you can wipe and clean the motor, and then find the leak as the temp builds with it running. The usual three pages of cautions apply.

There are many hoses on this engine that can leak for you too.

A head gasket is not impossible, but I do not recall (like that means anything) seeing anyone here with a head gasket leak like this. Lots of t-stat, heater valve, hose leaks iirc.

 

i did let the engine run a while yesterday and as the engine got warm it dryed everything off. i was looking for the leak to see just where it was coming from but never saw it. even a couple of hours later it was still dry. then today it was wet in the valley behind the tstat housing. but it didnt look wet at the tstat housing.

 

I have the same exact problem on my ex wifes 2006 4.0 explorer. 122k miles. She ran in hot for a day without telling anyone, running it until it cut out on the highway. In the past week, I have replaced the thermostat and the cracked radiator. Now when I go on short trips no problem with overheating but Iam noticing coolant in the block cavity behind the thermostat housing. I think the leak is coming from the rear of the housing, but I took it to Pep Boys yesterday and they ran a pressure test. They said that they ran it for 10 minutes and nothing then after that they had a positivie test for hydro carbons in coolant. They said it was a blown head gasket but they did not sound real sure. I also have a high reving sound when i accelerate. No milky oil, no smell from exhaust. How did your situation turn out on your truck??? please advise, I was going to replace housing but now after pressure test I am at a cross road. Pep Boy master tech said it was weird because normally it test positive right away and mine took 10 minutes of running.

 

My Sport Trac just started leaking coolant. I can see it leaking out roughly where the head mates to the block right behind the alternator mount. It's hard to be sure but I pulled the water pump and saw no sign of damage to the gasket behind that. It never over heated and I don't see any signs of coolant in my oil or oil in my coolant. Anyone ever have to replace a head gasket?