Coolant Leak. At My Wit's End!!!!
 

My 02 f150 crew cab with a 5.4 and 180,000 miles has developed a water leak at the rear of the engine. It seems to be more on the passenger side than the driver side, but the coolant leaks from the rear, running down the transmission bell housing. I cannot see the source of the leak, but I can see some coolant deep down in the top of the engine around the intake manifold making me think it is near the top of the rear of the engine. The primary leak, however, is coming from the bell housing area. The truck has the original hoses, water pump, heater core, and all cooling system parts. It is impossible to see that area of the engine. It has never run hot. Runs great. The leak is worse after turning off the engine and letting it set a minute or so. The two heater hoses are not leaking as far as I can see, but I can't see the one that connects to the rear of the manifold. I can reach it, and do not feel any leak.

Can anyone tell me what to look for?
Thanks,
Will Walker (WOW)

Off the back of the water pump is a hose to a line that goes the length of the valley under the intake manifold.
Best bet is to get an inspection mirrior and a light to see under the intake area for the leak point and even presurize the cooling system to force the leak to show.
Look for trail signs of the leak form it's origin.
The leak is heat sensitive to the point it seals when parts expand from heat..
In any event you will need to remove the intake assembly to effect any repair.
A gasket set for this operation and anything else you decide to replace while it's apart.
See a Haynes service manuel page 2B-14 figure 11.24. Most auto parts stores carry this manuel.
Good luck.

Intake manifold gaskets, or one that hose under the intake