A month or so ago, I replaced a cracked exhaust manifold on my 04 Lariat. A week or so later, it started leaking on the back two cylinders, so I pulled it off yesterday, and the gaskets that came with the Dorman replacement manifold had began to to separate from the three layers they consisted of, yet still in one piece. So I installed two new Felpro gaskets, which looked to be a better quality product.

HOWEVER, after cleaning the cylinder head, installing ANOTHER new set of studs, and installing the gaskets, I still have a faint leak at the front of the engine. I tried sparying soapy water on the manifold while it was cool, and I can't see bubbles, but while my girlfriend covered my exahaust pipe, and I can hear it leak. And I can hear it leak under a load.....

As many of you know, removing the manifold is a PITA! I'm not really looking forward to pulling it off again!!

Is there any advice on what it could be? I'm worried that I could have scratched the heads surface a little too much....

And now that I'm thinking about it, I didn't pull the manifold from the engine compartment and clean it's mating surface, but the gaskets looked to have not torn at all, so I'm wondering if I could have left some material on the manifold.

 

So I've been doing research, and ive found that exhaust system that are welded, as mine is, i have hi flow magniflow converts and muffler, cause stress in the manifold itself. Also, there is the rubber bushing/damper that hangs the exhaust on the cross member that could nned replacing, and that could help prevent future leaks.

Im just brainstorming :-)

 

You used a factory style manifold? why not put factory steel gaskets back on it?

 

I ASSumed that the Dorman gaskets would work, and when I went to buy new gaskets, the thought of factory parts escaped me. I think I'll run by ford today and pick some up, I'm so not looking forward to the installation!

 

yeah it sucks lol

 

I went to Ford yesterday, picked up two new gaskets ($20), I'm not doing it this weekend though.

Funny thing though, the Dorman gaskets I complained about earlier, are made in the same fashion. The gasket from Ford looks as if it's trying to split in half, so I retract my original statement about a failing gasket. Sorry Dorman

 

I've replaced my stock right exhaust manifold with a Dorman OEM replacement from Advanced. It worked fine for a week, THEN it started leaking toward the back. I assumed it was the gasket, so i bought Felpro.

They leaked in the front. SO, the stock ford gaskets are thicker than the dorman, so i replaced the felpro with those. And it STILL leaks. I'm thinking this manifold is warped, which is something I should have checked the first time, instead of paying $9 for studs, three times, and buying two other sets of gaskets.

Anyone have a different brand of exhaust manifold?

izzy