I have a 2006 F150 screw 4.6 auto 116k miles that has evidence of a small coolant leak where the intake manifold joins the head, This is on the drivers side directly under the thermostat housing. The t-stat housing is dry and the hoses all appear dry. It's just wet right at the gasket where the manifold joins the head. Reservoir is still normal so it's not leaking too much just yet.

I searched this site and youtube but didn't find any other posts. Lots of problems with older trucks with composite manifolds but nothing for this one. It looks like a part of the bottom of the manifold is plastic but the entire top and where it is leaking is all aluminum.

It seems odd that this would start in the winter time just driving back and forth to work (no load). And, yes the antifreeze is good.

Just wondering if this is a known issue with this truck. Is it just a matter of replacing the gaskets or is there some other flaw I should be concerned about?

 

I am no expert , but , I would fix this as soon as possible . I have seen a few , older 4.6 engines , bend a rod from intake gasket failures after shut down . After shut down , gasket fails , coolant fills intake port . Water won't compress , rods bend . Maybe someone else has better advice though ...

 

ok, at least it's starting to warm up some outside. I guess I need to get the gaskets and find the torque values and tightening sequence for the manifold. Any other suggestions while it's this far apart? I'll look at the vacuum lines closely but what about replacing the fuel injector O-Rings? Anything else?