Hey yall. I just got a used truck, 02 F150 w/ a 4.6, and it's got a slight water leak. It seems to be a small crack in the head, just under the thermostat housing. It only leaks when the engine is warm and there's pressure in the system. It's an old company work truck, and the mechanics used some type of epoxy or jb weld on it. It's not a bad leak, but it is noticable. What options do I have as far as head replacement? I believe they are the Non PI heads, oh and it's a Romeo motor with 147K on the clock. Also, while driving with the A/C on, anytime I give it any gas the air stops blowing through the vents. It's like it gets redirected somewhere else. Any ideas what could be causing that? Thanks for any help.

 

Without taking the head off you really don't know how deep the crack goes. Watch your coolant level and your oil for coolant in it. Being a 02' you should have PI heads. The air/vent problem should be a vacuum leak that is probably a broken hose behind the battery going into the firewall.

 

make sure it is the head that is leaking. I know the mustangs have a problem with the coolant crossover on the intake manifold cracking because it is plastic. If yours is plastic I would have to say you need a new intake manifold. But I don't know if the trucks have a plastic crossover. The mustang 4.6 replacement manifold has an aluminum crossover.. and can be bought online for $150. A lot cheaper than a head. I don't know the price for a F150 replacement.. but should be easy to find.

 

Most of the crossover is accesisible if you remove the alternator and the intake track. I would not jump to conclusions without a better look first. At just 16 psi pressure JB Weld could be the answer.

 

Nope, it's all aluminum. It's not the crossover, it's a spot in the head just behind and below where the thermostat bolts onto. I've already pulled the intake off and got everything else off so I can get the timing cover and head off first thing in the morning. But it was a company truck and they tried to fix the problem by the cheapest means possible, JB weld, and it worked for a while but it got a lot worse. Thanks for all the input guys.