brought the F150 in for service, everything seemed fine, came home parked truck in the drive. latter I notice liquid under the truck and determined it was coolant, nothing was leaking, checked the tank it was slightly low so without the truck running I filled it to where it indicated full/cold. looked under the truck and water was streaming out at rear of engine. leak stopped and tank remained about the right level. decided to start the truck and stand by. when running it began to leak again as the truck warmed up but soon it slowed to one or two slow drops. level of water is a bit low but not critically low. engine runs great and does not over heat, but if I fill the tank to proper level it begins again? what am I dealing with here?

Not sure why I have a coolant leak that ends up at the back of the engine to the ground but only when I fill the reservoir. had it running with no problem but if I top off the reserve it leaks out at the back of the engine so is there an overflow somewhere that causes this or do I have bigger problems. I can not fin where it is coming from?

 

The Introduction forum is not for posting technical questions. I'll contact a moderator to move this to the correct forum.

 

97,98 and 00-03 5.4 are notorious for having the plastic intake crack and leak coolant into the valley

there's also a cross over coolant pipe the runs under the intake IIRC






Threads merged. One thread per topic, helps us help you and keeps others from being confused. Thanks

 

I was afraid that might be it, and I suppose that sounds pretty logical, although I can't figure why the only time it leaks is when I add about two inches into the expansion tank which will cause it to leak until it hits the lower mark and stop. I can run it and it reaches operating temp and does nothing unless I fill the expansion again. I would think that the expansion of the coolant would cause it to leak. even when it is cold it will leak out until It reaches a lower mark on the tank...weird.

 

Did you figure out were leak was? I have same problem. I think mine is small leek in heater core because my windows fog up

 

Dorman replacement intake on ebay. Updated design. I think its better than the oem intake from Ford. I used them. A lot of times you will end up w/ a dirty slim in the tank too. Patman's right about the intakes cracking from age and heat.