klm20_2000

Ok I need some help with my F150. I have a 98 F150 4x4 with the 4.6 engine. It has about 179000 miles on it. It is still a good truck and seems to run smooth still. I am having an issue with the passenger side exhaust manifold sealing to the head. About 5 months ago I had a terrible exhaust leak. Took it in to get fixed and it had a couple of bolts rusted/broke off for the exhaust manifold. The bolts that attach the exhaust pipe to the manifold were also rusted off. I got all that taken care of and planed the manifolds and installed new gaskets. Passanger side still leaked after this. Shop said they would try doubling up the gaskets at no cost so I took it in a second time. After doubling up the gaskets on the passenger side it sill leaked so they put a new manifold on there and it still leaks. I have been driving it this way now for a couple of months and it is pretty annoying. You can actually feel exhaust coming out between the head and the manifold on the very front cylinder on the bottom. I don’t know if the gasket is actually blown out or not. I am basically trying to figure out why it will not seal up. Could my head be that messed up? Could it be a plugged cat causing it to blow out? As far as I know the cats are stock. I have true duel exhaust straight to the cats. The last ditch idea I was able to get was use the ultra high temp silicone that a local mud racer uses on their trucks. For a little more information I am also getting the EGR code, but I am also getting a lean code for the left and the right side. I don’t know the exact number of the code but I should be able to find out this weekend. I am also getting pretty bad gas mileage; the max I can get anymore is about 14. Anybody have any ideas on what my problem is and which direction I should go?

TrickyRick

I had the same problem except it was the back bolts. The dealer replaced the manifold cause it warped after the bolts broke. Then the other side went a year later and the repair was the same. Now it is 4 years after the first manifold was replaced and no warranty. After talking to numerous mechanics I came to realize ford used crappy bolts and manifolds. This is a very common problem so I am thinking of going to headers. I haven't found any that are a direct replacement for the factory manifold but I am still looking in to it.