2005 F250 w/ the 5.4L the passenger side exhaust manifold is leaking between the engine and manifold from the two ports in the rear of the engine. I want to tighten the bolts to see if that fixes the exhaust leak. I can reach up there from under the truck. Does anyone know what size these bolts are? I couldn't get a socket over the bolts because of the rust on the bolts.

 

they are 8mm studs so if i remember right they should be 12mm nuts but they might be 10mm

 

It's hard to tell due to the rust caused by high heat. A 1/2 inch wrench fit snug on my son's 4.6. Tap tap tap, do not twist hard as you may snap a stud off in the block, $$$$$$$ engine removal for sure.

Warning. Ford wanted 34 bucks for just one set, times 4 sets for the engine. Felpro sells asbestos, set of all 4 for 14 bucks. No way you can tell me the Ford's are better. Our stock gaskets totally fell apart when the manifold was removed. There were failure cracks right through the steel gaskets. Also all 4 exhaust studs snapped on our 2 manifolds. Now how the heck are we going to replace those????

 

Thanks o_i_f_03_04 The 10mm didn't fit and the 12mm didn't seem to either but I think I'll have to drop my starter so I can get in there better and tap the socket on.

murraydav did you have to do this on your psd?

 

^^^ my bad I just reread your post and saw it was on your sons 4.6.

 

When i took my manifolds off to put on my headers i loosened all of the nuts when the engine was hot while wearing welding gloves, i also sprayed them down with Liquid Wrench lubricating and penetrating oil that i got from wal mart and they all came off really easy for the truck having 80,000 miles on it. The nuts that were on my manifold were 12mm all the work i have done to my truck has been with metric tools

 

That's good to now - then it's just the surface rust on the bolts that makes it seem the 12mm isn't the right size. Also will try a 12 point vs. the 6 point I was using that might go on easier.

 

Thats a good idea about taking the bolt off while the engine is hot.
~Gage~