Noticed that my heat was weak in my f 150 and the temp guage was not getting into the normal range on cold days.Went to replace the thermostat last night and the long bolts that hold the thermostat housing on broke off when i turned them.It looks like the intake manifold will have to come off to fix this.I know that these plastic intakes are a problem and I plan to replace it while it is off.It looks like the bolts that snapped thread into the cylinder head.Probably coolant seeping into the threads for the last 9 years and 110k miles had caused the steel bolts to "loctiite" themselves into the aluminum head threaded holes.My plan(after the intake is off) is to drill the broken bolts and use an easy out to get them out.I figure some heat will help dissolve the coolant crud that is holding the bolts and aid in removal.Has anyone here had this problem and does my plan sound workable?Are there any other things that might be an issue to get this done.I need the truck to do a road trip in a couple of days and i need to get it done ASAP.Any suggestions or tips would be appreciated.I am going to rip it apart tonight after work and hopefully get it all done in one night. Thanks.

 

Well,the truck is back together after working on it most of the day.I had to drill out and helicoil 3 bolts that hold the intake down.I replaced the intake manifold with a new one while I had it off because it is almost 9 years old and I don't want to go back in there any time soon!Be warned.If you go to loosen the 2 bolts that hold the thermostat housing and they are stuck either STOP trying to loosen them or be prepared to go all the way in like I had to after they break off in the cylinder head.If you try to heat the bolts to loosen them you will melt the plastic manifold.All the other bolts that hold the intake down were also stuck but I was able to get all but one out by using an air chisel with a punch bit to beat the heads of the bolts and thereby loosening the stuck threads.I was not able to use the air chisel on the left rear bolt under the cowl and that was the bolt that broke off flush in the head.It took over 3 hours just to get the broken bolts out and install the helicoils.If I had to do it over again I would use a cutoff tool to remove the heads of any stuck bolts and then lift the manifold off the bolts.By doing this there is enough bolt left sticking up out of the head to use a stud puller and a torch to get them out without snapping them off in the head.The ford dealer in my town does not stock the bolts and the ones for the thermostat are very long and most hardware stores don't keep any 8mm x 1.25 bolts longer than 2 inches.Be prepared to hunt for bolts.I was lucky in that I stole 2 metric bolts the right length for the thermostat housing out of my cheapie Harbor Tool harmonic balancer puller kit.Well,I have great heat now and I am sure my gas mileage will improve as a cold engine is a thirsty engine.With EFI,cold means "choke".

 

Good info, thanks for the heads up!!

 

i uasually hang out on the 335 and the 300 6 forums. i was here for my little bro. i was gonna offer some adivice about heating bolts before you try, someting an old school really smart old man taught me when i was very young. but you GOT it. my point sounds to me, you did a darn good job mr. that kind of stuff can get dicey and exp quick like. good for you. pass it on. lots of young fellaS NEED PEOPLE like you. later paul md