I have a 2005 F150 Screw, 6" lift, 120K mils. I too have the dreaded exhaust manifold leak: both sides! Seeing how I am gonna be digging in down there I had a few questions to ask before I start.

1. What is the preferred gasket to use? Where to get them?
2. Bolts; factory/aftermarket? Where to get them?
3. Should I replace and go with new headers? If so, what are the benefits?
4. How long does replacement take?
5. Any special tools or expertise required?
6. How far up the creek w/o a paddle will I be in if bolts shear and at what cost?
7. Do you machine any of the parts ref warping?
8. What other problems may arise in doing this?

Thanks in advance. JW

 

Just ran into this problem......

I don't have all the answers but i can tell you that the passenger side is a major Pain.....
I found out that my manifold on the passenger side warped due to the cat plugging up, from what i understand these trucks are notorious for that.

I would not suggest headers to anyone unless they are going on a purpose built race vehicle. But that's just me and my experiences. They never seem to be durable in a DD. but some people will disagree with me.


you may be able to get it machined depending on how bad its warped. I had to buy a new one.

Are the Cats and exhaust stock, or aftermarket? The manifolds warped for a reason its worth looking into the cause....... This is a job you don't want to do twice LOL

 

The muffler hanger weld separated from the tail pipe. Not sure if this is the reason but could have contributed. The hanger has been repared but the leak sounds worst. Warped?

I have a Magnaflow single out cat back, Airaid cool air, and a Superchips to stock tuning only tire/axle adjusted per size.

I had a friend suggest headers. I am thinking of leaving stock. Sounds like more problems to come.

Is this a job a guy can do at home in an acternoon or better off paying someone while I watch football?

More often lately I wish the truck was bone stock. But if it was, I would have already purchased something different!

 

I am going to tackle this I think I am just trying to get the courage. I ordered new gaskets and I am going to order a new manifold as well. Mine is just the passenger side. What was involved in replacing it? Any special tools or tricks?

Mine warped or blew the gasket because I had an injector go out while pulling my camper and a mechanic said that would cause excess heat.

 

I think leaving them stock is the best idea. As long as you have patience you could probably handle it but its going to take an afternoon or two....... Its not an easy job if that's what your asking. No special tools.

Worst case scenario: if you cant do it, take it in......

you'll know when you pull the manifold off if you need to get a new one. If it can be fixed, a machine shop should be able to mill it for under 50 bucks.....

I doubt the warped manifold was caused by a broke exhaust hanger. My guess would be it got hot, or bad casting...... But who knows if you took it to a shop they may have a better guess at what happened.

 

My learning experience with '99 4.6 passenger side manifold was a boot in the butt. I should have jacked the engine up a little (unbolt engine from mounts). Even an inch would have helped. I had a very warped manifold, so I cut it up with the sawsall to reach the lower nuts. I did not break any studs, but they were all in terrible condition. I rolled some out with Sears bolt out number 2, and the rest with one of those cam tools. Scary.
My frustration was caused by the lack of room near the motor mount. I could not get the manifold across with the studs already in, so the lower middle studs had to wait until I had installed the manifold loosely on the upper studs. Thank you for the universal joint on the ratchet. I also had to grind off some of the flange from the nut on the stud above the motor mount so it would spin past.
So, next time for me is a) jack up engine and b) remove starter.
I have been a Ford guy for 30 years and this is the first time I have cursed about the design. Are other trucks this hard to do manifold work on?
I have a '95 302 that is next in line.

 

I gave up working on my own stuff years ago..But I just had this problem 2 months ago.. My buddy did it in his garage, took him about an hour (passenger side). He replaced the manifold and gasket and charged me 100.00 and I was glad to pay that after checking around...

 

My passanger side manifold has been replaced 3 times under warranty. About every 2yrs it starts ticking again. Very irritating. I don't understand why they can't keep these from warping...Truck is stock except for a magnaflow muffler, and has 84k on it.

 

Im tackling this job this saturday on my passenger side too. Dreading it, but i am going to do what I was told up here:

1) remove wheel and tire
2) remove inner fender liner
3) remove starter
4) unbolt and tack up motor 3/4"-1" on that side
5) The previous week, i am going to spray the studs and bolts with PB blaster for the full week up till we do the job
6) use heat to heat up studs
7)pray to God, I dont break a stud

 

Tick...tick...tick...

 

A torch for that long? Not an acetylene cutting torch, a minute of that even with out oxygen blast would melt that bolt. And if I'm not mistaken aluminum heads and acetylene cutting torches do not mix... I'd use it but not for long... Unless it's a little blow torch that uses that. Then that's a little different. Steel heads would be a diff story. That's for Dixie.

As for my tick I went with good gaskets, bolts and ss shorties. Stainless because I want to has the truck for a very long time and never have to crawl around there replacing them again. I am no mechenic but it got done with time. I even left two stock studs in bc I didn't want to shear them, they wouldn't come out and they looked pretty good in terms of corrosion...

 

Yep, you're right. I'll disagree with you.

I know many, many, MANY folks who have and do run headers on their DD's for thousands upon thousands of trouble-free miles. Of course, some of that will depend upon the quality of the headers.

Besides, they can't be much less durable than the Ford factory manifolds.

 

truth spoken lol.

 

Yep...

 

Just had mine changed. I wish I did it myself. Now I'm out $1085. Now they tell me I might have to change the other one in a few months.