Replace Exhaust manifold gasket

[baz70]

hi folks, I have an exhaust gasket leak, not sure which side, not good so I want to get it fixed. Wondered, anyone tried replacing, and how big a job is it? I took a quick look in the engine bay earlier today and could barely see the manifold bolts..... Can I get to them easily from above, below or will I need to lift the engine out? It's a 351 Cleveland 4V. Pics would be appreciated. thanks....

 

[oldmountainfarm]

It's a pretty easy job. You should be able to get to all the manifold bolts to the heads from the top and the manifold bolts to the exhaust from the bottom. The main problem is that the bolts are usually pretty rusted. WD 40 and a good 6 sided socket is the trick.

 

[baz70]

It's a pretty easy job. You should be able to get to all the manifold bolts to the heads from the top and the manifold bolts to the exhaust from the bottom. The main problem is that the bolts are usually pretty rusted. WD 40 and a good 6 sided socket is the trick.

thanks mate, will take a look in the morning, weather permitting will do the strut rod bushings first and then take a look at the exhaust manifold bolts and prep them for removal (will order a new set of bolts first and replace)

 

[Nance]

Not hard to do.Soak the bolts with some penatrating oil.

 

[will e]

It should be obvious which side it is by the sound.

If not, use a mirror and look for a little black soot.

And maybe it's not at the manifold to head but perhaps where they meet the pipe or ??

If you still don't know which side, the passenger side is a little easier than the drivers...

 

[Mr Mac]

You will, of course, replace both sides since you're in there, right?

 

[baz70]

sure thing, thanks guys, its not something I noticed but upon a routine annual inspection one of the mechanics mentioned it, I have noticed mild smell of fuel when driving so I figured it made sense that one of the exhaust manifolds were blowing....

 

[c9zx]

Do you have tubular headers (extractors) on the car? If so, make sure the replacement gaskets are matched to the primary pipe size. Some racing gaskets for very large primary pipe diameters (2- 2.125) will not seal to 1.75 pipe flanges. I believe the original cast iron manifolds did not use a gasket. The Ford manual calls for the mating surface to be clean and applying graphite grease to the mating surfaces. an alternative I've used successfully is applying a THIN layer of RTV to the surfaces, bolt it together, let dry 12 hours before starting.

Chuck

 

[baz70]

hi Chuck, I'm not that technical and I don't know what you fully mean. I'll try and get a photo of the headers once I've unbolted and then will post, hopefully you folks can explain what I need to look out for. I bought some gaskets from NPD, so not even sure now if they're the right ones....

 

[akherber]

A few pointers since I not too long ago replaced my passenger side manifold.

1) Soak the bolts. They are likely rusted in.

2) If you cant break them loose at the angle you will be working at, you can unbolt one side of the engine mount and jack it up for easier access.

3) If at some point you have to keep searching for the leak, there is no seal where the manifold meets the exhaust pipe, it is just a cone. So just snug it up and keep looking.

Good luck

 

[c9zx]

hi Chuck, I'm not that technical and I don't know what you fully mean. I'll try and get a photo of the headers once I've unbolted and then will post, hopefully you folks can explain what I need to look out for. I bought some gaskets from NPD, so not even sure now if they're the right ones....

Let me know what you find and I'll try to help. Chuck

 

[73vertproject]

Spray the bolts periodically with penetrating fluid for a day or so. It's pretty easy to snap a bolt off, which makes your project a whole lot more complicated than it needs to be. Take your time removing those bolts.

Doc

 

[baz70]

Spray the bolts periodically with penetrating fluid for a day or so. It's pretty easy to snap a bolt off, which makes your project a whole lot more complicated than it needs to be. Take your time removing those bolts.

Doc

thanks guys, been spraying the bolts, not actually removed them yet, am I then correct in assuming there were no factory installed gaskets, and the ones I bought from NPD are aftermarket? in which case, if there is a leak, surely the only way to plug it is with a gasket ? if I go down the gasket route, do I apply gasket sealant?

 

[c9zx]

Am I correct in surmising the engine retains the factory iron exhaust manifolds? If so, are any bolts broken off in the head, any loose? If not, could the leak be where the exhaust manifold joins the H pipe? If you use the NPD gaskets you shouldn't need the gasket sealer unless the surfaces are terribly corroded.

Good Luck,

Chuck

 

[not2old]

Also when you get the bolts out, use a wire wheel to clean all the dirt and rust off before going back in. Makes things easier and maybe able to turn and start by hand.

Alan L