Specific Ford exhaust question

[Kira]

Friend's 1997 F-150 4.6l got a new ehhaust manifold on the passenger's side.
Where the leading end of the exhaust piping meets the manifold there's a small leak.
Is there a gasket available to quiet that?

Also, here's a funny thing. He just learned that exhaust manifolds on that vehicle go against the head without a gasket.

He was told that the layout benefits from easy start ups so things can expand into each other.

This feature has nothing to do with his small leak. Likely the RockAuto sourced parts (asymmetrical Y piping with new cats) did.

 

[Trav]

All the ones I have done on those had manifold gaskets, if he didn't put them in that's probably the source of the leak in the rear.
for also had a TSB to use SS studs which I also used (you don't have to buy them from the dealer) along with copper nuts.
On the cone flange you shouldn't need anything if its tightened properly.

Edit: You can smear a bit of this on the flange before tightening pipe to pipe/flange is exactly what this stuff is made for and it last indefinitely in these applications, it is not for filling holes.

https://www.amazon.com/Custom-Accessories-MUFFLER-SEALER-6-OZ/dp/B001DKNIJQ

https://www.rockauto.com/en/catalog/ford,1997,f-150,4.6l+v8,1122477,exhaust+&+emission,exhaust+manifold+gasket,5400

 

[OVERKILL]

Trav is bang-on.

There should be a gasket that goes between the manifold and the head, and the ball flange seals directly against its mate on the Y-pipe. The updated hardware is as Trav described. Sounds like there were numerous installation errors here.

 

[Trav]

Just to add to this thread. After doing the manifolds adding liner extensions is one of the most important things you can do to keep the new ones in good condition. I use to buy them but forget the company I got them from but this is a good thread on it. It is a very worthwhile add on.

https://www.ford-trucks.com/forums/1314033-installed-front-wheel-well-splash-aprons-5-0l.html

 

[SwampSurvivor]

There's definitely supposed to be a gasket between the manifold and the head. A lot of people double gasket them, even.

 

[bdcardinal]

There are gaskets between the head and the exhaust manifold, there is no gasket between the manifold and the cat.

 

[Kestas]

For two of my cars I made copper gaskets for the manifold where it mates to the head. They're robust and reusable.

Sometimes cars have a gasket where the manifold exits. They look like a dense steel wool donuts. They're designed to take up movement and can get used up. Though I think they are assembled with springs under the bolts to give constant compression.

 

[Kira]

Thanks all for responding.
I went by a Ford dealer today and the parts counterman printed me the page from his system.
There were gaskets.
I can't wait to show him.

 

[spk2000]

We make the super duty F-250 and 350 exhaust systems and there is no gasket on the y-pipe mating to the engine. Just a ball and socket type of connection. I would think the f-150 would be similar.

 

[bdcardinal]

Originally Posted By: spk2000
We make the super duty F-250 and 350 exhaust systems and there is no gasket on the y-pipe mating to the engine. Just a ball and socket type of connection. I would think the f-150 would be similar.


Correct, the manifold to cat is a ball and socket.