Hello all! Little history here before I begin.
99 F-150, 4.2L, auto, 150+K miles. New maf, and Motorcraft wires & plugs.
Truck runs well, BUT, noticing small coolant leak on the driveway. The tank goes down a inch or so after a day or 100 miles. Am finding coolant at the bottom of the bellhousing ( under the torque converter). Front of motor seems dry as do freeze plug on block side.
It is hard to see anything under this thing when I slide under.
Could it be a plug in the back of the head? Any ideas?
Thanks in advance.

 

Hi and welcome to FTE! Glad ot have you here!

I reckon it could be coming from most anywhere. Earlier model years had problems with leaking lower intake manifold gaskets (which resulted in an internal leak) and sometimes a leaking timing chain cover gasket.

In your case, I'd check the front very closely, and look around the water pump (there is a weep hole that might be expelling some fluid)
Maybe it is leaking towards the front and getting blown to the rear?

There is a UV dye you can add to the coolant that will casue it to glow under a "black light". That might help find traces of coolant you might miss otherwise.


Good luck and let us know what you find.

Oh, and once again, welcome to FTE!

 

well, I looked under the truck. All the freeze plugs are dry. The water pump and fromt cover are dry. I started looking at the driver side head and it was dry. Then the passenger side. Hmm. Seems a bit of weepage around the back where the head mates to the block. There is even a drip seen. I pulled the oil dipstick and the oil is fine. Same with the oil filler cap; seems fine.
Now, is there a coolant passage on the outboard side of the gasket that would slowly drip but not mix with the coolant?
I priced a top end head gasket kit and if I get the head bolts too the price is about $225. That is for Fel-Pro.
Does this sound like what I need?
Thanks.

 

Sounds like you are on top of it.
Now just a matter of money, time and work ?