Well my truck once again needs help, this time it’s a coolant leak. Appears to be coming from the 90degree pipe under the throttle body. I replaced the hose that connected from said pipe to the water pump and it drastically slowed the leak down but didn’t stop it all together. As best as I can tell, I have to remove the upper intake for the sake of needing room but my questions are these:

Do I need to remove the lower intake to which that pipe is connected to in order to remove and press a new one in?

Special tools required?

Do I need to worry about coolant seeping past the lower manifold gaskets and causing damage?

and finally, what other plumbing should be replaced while my upper intake is off? Stuff that I can’t do with the intake completely assembled or is extremely difficult to do so while assembled. I know new gaskets and probably new isolator bolts as well even though these are only a couple years old.

I do have a repair manual but it conveniently skips over this part I’m trying to replace. Perhaps unrelated but it didn’t leak until I had it parked for three weeks rebuilding the front end and I noticed it after taking it to Firestone for an alignment. My cruise control also stopped working as well during this time but I’m not worried about that as it’s not detrimental to the operation of the truck. This is on a 2001 F150 with the 4.2 V6/5spd rwd.

 

I read up on this issue a couple years ago and found lots of videos on youtube. Some worth consideration are :

It looks like you can get to everything by just removing the upper intake. Good luck with the repair.

 

I was really hoping to not having to remove the intake but thanks for confirming that. Every video I have found showed the lower aluminum intake removed as well and I’m really just trying to avoid removing more than I have to. Thanks for the videos!

 

It is however a good idea to pull the lower, clean everything to eat-off-it condition and replace the lower intake manifold gasket to fend off eventual failure and hydrolock which cost me an otherwise excellent 200K+ mile 4.2. Mine had been fitted with the later style intake and still leaked but did last a long time. The 4.2 is a disappointment compared to the glorious 300 six but I like the F150 mine's in so it got a used engine.

 

Even if they were replaced two years ago? The truck only has 39k miles on it and it wasn’t carboned up when the intake gaskets were done for the P0171 and P0174 codes.