Coolant leak

SP_51-F1 · #1 11-21-2012, 04:45 PM

2006 FX4 SuperCab 2-door
4.0L SOHC w/ Automatic

I smelled a faint hint burnt coolant when I got home and exited the truck last night. I've never smelled this newer coolant burnt before, and I did not recognize it at first.

This morning, walking to the truck in the store parking lot down the street, I noticed a fairly large wet spot under the passenger side of the front end. I was not sure if that was my spot, but I decided to give it a look when I got home.

I made the short drive home and the truck seemed to run fine. I checked under the hood (figured out what the smell was), and there is definitely a coolant leak somewhere, it's all over the passengers side of the motor. The overflow was empty and the radiator took almost 1/2 a gallon of water to come up to the top.

After topping off the overflow and radiator, I pumped/squeezed all the hoses that I could reach but I was unable to force water out anywhere. I found no leaks in any hoses I could reach and inspect.

I started the truck, and immediately water started to drip on to the driveway. It seemed to be running down the front and back of the engine block, mostly to the passengers side. I saw no water coming out of any hoses.

I cut off the engine and looked over the hoses repeating the pumping/squeezing test. I found nothing wrong with the hoses and never found the leak. I did find water in the valley between the heads.

Are there any hoses that normally fail?
Are there any hoses that route under the intake?
Is there anything that could fail on top of the motor? (Temp sensor, etc.)
Water pump failure?
Head Gasket? (I doubt it, it seemed to be running fine.)

reconjb · #2 11-21-2012, 04:49 PM

the intake gasket is on the top of the motor and has coolant running around it although normally it will allow coolant into the intake and foul out plugs but i guess it is possible to blow the other way

djfllmn · #3 11-21-2012, 04:52 PM

thermostat housing cracks

SP_51-F1 · #4 11-21-2012, 05:05 PM

Quote:

Originally Posted by djfllmn

thermostat housing cracks

Thanks!

I feel that is where it is coming from but I can't prove it yet.

Any particular place I can look before I tear the top of the truck off? Is there a common place where they fail? I'd like more than a feeling to go on before I tear into it.

lcplschooley · #5 11-21-2012, 08:12 PM

If not thermostat correct me if I'm wrong but could be a head gasket? I've never expierenced one but I know a buddy who had the same thing (Dodge go figure) and he ended up overheating and fried the motor. And you should be able to tell if the thermostat is bad cause the engine temp gauge wouldn't move? Yes no maybe please correct me if I'm wrong lol like I said never fucked with a coolant leak (knock on wood) in my ranger

djfllmn · #6 11-22-2012, 05:43 AM

if the head gasket was bad then the oil would be milky

lcplschooley · #7 11-22-2012, 05:52 AM

Well he hasn't said anything about his oil but dieant a cracked head gasket leak Coolant and come from the area he's talking about?

ricochet · #8 11-22-2012, 05:53 AM

Guess: i think there are coolant hoses to to pcv valve at the top back of the head. Maybe something worth looking closer at...

SP_51-F1 · #9 11-24-2012, 04:11 PM

It was a cracked thermostat housing.

I never would have thought the housing itself had cracked. I was looking at every hose and connection on the t-stat housing instead, but of course they looked fine. Once I knew what to search for, it seems this is not a rare problem.

Thanks again, djfllmn.

djfllmn · #10 11-24-2012, 04:28 PM

no problem...glad you got it fixed