2006 Explorer 4.6 V8 Exhaust Manifold Gaskets

[jk86racing]

I just ordered a set of exhaust manifolds from Dorman. In the picture from RockAuto they showed it coming with the OEM type multi layer steel exhaust gaskets but when they arrived they had the graphite type gaskets. Does anyone have any experience with the graphite type gasket on the 4.6? Do they hold up over time? Should I use copper spray or high temp RTV on them? Am I better off getting a set of the multi layer steel gaskets from Victor Reinz or Ford?

 

[Bill MacLeod]

Laminated exhaust manifold gaskets have been used forever, why spend more money? You've got them, so use them.

Re-stud both manifolds recently and I used hi temp RTV on both sides of Felpro laminated gaskets, also used double nuts on all of the studs. All's quiet for now.

What are you using for studs?

 

[jk86racing]

In my experience anything is going to seal the manifold, just which is going to work the best. I know mls gaskets work great if both surfaces are perfect, but imperfections create issues. Graphite works good but doesn't always last as long. With me being new to the 4.6, I've read it seems to be picky on the exhaust manifold side so I'm just trying to get a feel from peoples experiences. Spending a little more right now to save me a headache later works better for me.

Right now I have Dorman manifolds, with graphite gaskets, and stainless steel studs from Metric Tool & Screw Company.

 

[Bill MacLeod]

You have all the parts, with a good supply of tools, time and patience, you should be able to silence those leaking manifolds.

Tools that I found of great help:
- right angle drill.
- automatic centre punch.
- left hand drill bits. (or sheeters/stubby drill bits about 1/8" in size)
- tapered/fluted extractors.
- stud remover. (think I have a Titan)

Best of luck with your project.

 

[Explorer_PL]

That might help some. It was a royal pain, but doable.

http://www.explorerforum.com/forums...ds-replacement-on-4-6-v8.416927/#post-3354454

 

[regtocruiser]

Be prepared for broken studs as you take everything apart. And if you have a hard time accessing the broken stud you may be into a cylinder head removal. Plus side is you get to install new head gaskets.

Ask me how I know.... And btw the replacement studs are bronze-copper alloy that will not rust and break overtime. Thanks Ford.

Common issue on the 4.6 and 5.4 is this one over time. More and more common as these vehicles age.

Lets just say I had a dealer pull my cylinder head on and off. Ford offers a 2 yr unlimited mileage warranty. Hard to beat if you want a quiet engine.

 

[jk86racing]

Oh yeah I definitely know about the broken studs. The exhaust has been dropped and the exhaust manifolds have been off for a little while now. What I found was 2 broken studs on the passenger side and 3 on the drivers side, 1 of which is behind the shock mount. I've got my fathers automotive machine shop at my disposal so that does help but needed to get some things before I started. My plan is to use a rectangular plate that has a slot on one side to bolt over a good exhaust bolt hole, and a hole on the other side that will accept a drill bushing of various sizes. That will allow me to position the drill dead center over the broken stud so I hopefully don't damage the threads in the head. Using an angle drill and a short (screw machine) left handed drill bit I'll drill a hole with the hope it turns the stud out. If not I've got a set of bolt extractors to use. If that doesn't work then I'll drill it out and put a time-sert in and call it a day. If its anything worse I'm pulling the whole engine and working on it that way.

My main question was just about the parts being used; mainly the exhaust gaskets. From my experience its usually good practice to replace what was there with the same thing. I know on a rough surface the multi layer steel gaskets can have a hard time sealing. When we machine cylinder heads and blocks you have to make sure that A it is flat, B that it is square, and C that you have the correct surface roughness. If people have had good luck with the graphite gaskets then forward we march. If people have found them to be junk and the mls gaskets are the only way to go then I order the mls gaskets. I'd like to save money on this whole ordeal, but more than anything I would like to do it right the first time.

Thank you guys and gals for all the help and suggestions!

 

[Bill MacLeod]

So is there a right way, or a wrong way? Time will tell.

Why have Ford trucks with mod motors had such a problem with broken studs, stud falling out, etc ? Over engineered or just using inferior materials? Maybe both?

From my observations, there was no corrosion on the oem studs, nor sealant/antiseize of any kind. But there is a non thread area on the studs that would prevent them from bottoming out in the head. This is where they break and probably lock into the head. When I drilled one out using an stubby bit, it actually went about 1/8" further into the head. Drove in an extractor and literally backed it out with my fingers. Don't think you will have any problem with left hand drill bits.

Remove the motor mount bolts, loosen the a/c compressor on right side and same for the p/s pump on left side. Move them out of the way as far as possible, place pc of wood on jack saddle and lift one side of oil pan as high as possible to allow better access to the studs.

You have a great plan for removing the studs, so do it. Your overthinking the gaskets. Hi-temp RTV is your friend here. Also consider using a second nut on the studs after the first heat cycle..

btw, I used the same s/s studs that you have.

 

[Explorer_PL]

I think broken exhaust manifold studs are problems on many brands / motors.
It looks tight there, but once the manifold is out, you have more room.
I would pull the whole engine out before taking the heads off, why mess with timing and everything else.
Like Bill said, piece of wood under the pan, and you can raise it a little, that helps, one side at a time.

 

[boominXplorer]

I think the issue is more of the manifolds warping on the 4.6 / 5.4s. Then the studs stretches and finally breaks. I have an 07 Mountaineer in my shop with 140k miles and exhaust is leaking horribly from the manifold on select cylinders. You can clearly see 1 or 2 cylinders on each side leaking where the next one over is perfectly sealed. It also has NO broken studs.