Hi everyone, I have a 1998 F150 with the 5.4L engine and it has a rust hole in the passenger side exhaust manifold which I understand is kind of a common problem on these trucks. I know it will be a pain in the neck to replace so I would rather just drive it with loud exhaust for now. But what I am wondering is whether or not my valves could get damaged from lack of back pressure or other implications of low back pressure.

 

Loss of power for sure. I guess it's possible for cold air to get back in thru the hole.

You can also score some crappy shorty headers used for $100 or so or new for $200.

It must have rusted out at the flange ?

 

Besides the noise and possible exhaust gas into the cab, the possibility of air being detected by the OX sensor can shift the fuel tables for that bank to the rich end, setting a code.
Otherwise no other issue except burning something close by.
If it is such that a strap clamp of some sort can be used to hold a patch cover over the hole would be prudent.
It will only get worse.
Good luck.

 

Thanks for the responses guys . Im glad to hear that my valves are safe because Im really gonna have to rely on my truck during this upcoming Wisconsin winter, eh. The loss of low end torque kind of sucks though, but Im going to try to make some kind of patch like you suggested Bluegrass.

 

How big is the hole? Can you get to it? You can pull the inner fender-well easy enough if need be.

 

It's kind of a PITA job, but if you're going to do it start soaking those pins down with PB Blaster/Deep Creep/etc. I soaked em on both banks for a week solid while the engine was still hot and when i finally went in to pull them i didnt have any stem snaps.

Now... the solid brake line was another issue... i think it was just being held together by rust. Deep Creep ate right through that bastid.