I was driving home last night and the truck (96 F150 XL 5.0 302 e4od) started making a new noise. At first I thought the small hole in the muffler had got much larger. By the time I got home the engine was running rough. It was idling rough this morning. I followed the sound to the left side of the engine. It does not appear to be a mechanical sound. More like an exhaust leak. I noticed that part of the manifold, right at the joint with the exhaust pipe, appears to have corroded and fallen away leaving a jagged edge on the left side. Check engine light came on while the truck was idling which makes sense since there is an O2 sensor right there.
My questions:
Assuming that the loss of material on the tail pipe connector plate of the manifold is the issue is there any way to patch this without replacing the manifold?
If my problem is a leak in the manifold why would it cause the engine to idle rough? (is the engine reacting to info from that sensor?)
Thanks much for any advice/comments.
Phil

 

Well from my understanding you will have to replace the manifold, that is if I am reading it right that the manifold had fallen apart and not the pipe that connects to it. Look around at the Junk yards I got a set for my 5.8 for 67 bucks that are in good shape. It being a 5.0 you should have no issue locating set or just the one side,I would change the pair if it were me. Just my advice.

 

Thanks for your response. It has been determined that it is the manifold/exhaust pipe connection by someone who knows better than I do. I am wondering now whether to buy only the left manifold or buy a set of shorty headers. I saw somewhere that certain brands of shortie headers actually meet the exhaust pipe exactly where the manifold did so you do not have to re work the exhaust connection. Has anyone had any experience with this?
Thanks again!
Phil

 

shorty headers generally are bolt-in replacements for stock manifolds however you also don't get the same gains as you would from long-tube headers, if anything at all. don't cheap out, get thick-flanged units from a name-brand. unless I could find a set that I could verify added noticeable gains in some area I'd just get manifolds.