Exhaust manifold gaskets

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Colt45ws

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The '04 Dodge Ram (4.7L) has failed its exhaust manifold gaskets, it has already had one side (passenger) done by the dealer (for $100). So I just ordered a set of fel-pro gaskets to replace them. I want to know how to ensure this does not happen again. Im going to torque them right, then torque them again after a heat cycle. Any other tips?
cheers.gif
 
Check your head manifold gasket mating surface for warpage, irregularities and pitting.

Also check to ensure that your exhaust manifold mounting surface is free from warpage also.

Get a factory torque spec for the exhaust manifold flange nuts/bolts and torque them to spec.

Drive!

Q.

p.s. sometimes, due to manufacturing defects, poorly casted exhaust manifold assemblies, etc. exhaust manifold gasket may leak again no matter how meticulous you are in prepping the surface and torquing them to spec. Factory usually release some sort of TSB or similar down the road if this is the case...so stay tuned.
 
I make my own exhaust gaskets. I've been doing so for a number of years. I make them out of copper sheet. It's an old hot rodder trick I learned to make reusable gaskets that won't blow out. A combination of drilling, sawing (coping saw), and filing usually makes a good gasket.
 
I use copper sheet that I bought from the local roofing supply. I don't know the actual thickness (0.030"?), but it's somewhat flimsy. For smaller gaskets I've taken scrap plumbing pipe - which is thicker - slit it, and flattened it. Once I've cut the gasket, I put it between two pieces of steel plate and hammer away to get it flat again.

If you've ever looked at my profile, you'd see that I'm a metallurgist. I tell people that a metallurgist is basically a blacksmith with a degree.
 
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I just finished taking the passenger manifold off, and it was a cakewalk to do it. Only has taken me about a hour and a half. Once I looked at the gasket I can see it was leaking as well, not just the driver side as I had thought. Interestingly, they were both leaking at the rear-most cylinders...
 
They may have been poorly machine from the factory. Have them resurfaced at a good machine shop. Then put good gaskets on them (whether copper or otherwise) with a film of Orange Hi Temp RTV. Use anti-seize on the bolts and some good hi temp lock washers. Bolt everything together and let the RTV setup. Drive the thing and get it good and hot then park it and let it cool off completely. Retorque and it should be good.

Most engines I build I don't use gaskets at all. I mill the head and exhaust flat, use good bolts/nuts and a film of RTV. They never leak. Once they have been in service for a long time I'll use gaskets as a service item if the exhaust has to come off for some reason.

Shouldn't cost more than about 50 dollars to have those manifolds surfaced, money well spent.
 
Alright. I just have to convince them it is necessary. Also, on the manifold->exhaust flange, Ive seen several different things used there. Once I saw orange RTV and Ive also seen anti-sieze used. Or do you think it should be dry?
 
Antiseize isn't going to help seal the manifold to head, it's anti SEIZE not anti leak. I would apply a good coat of anti seize to the bolts so they'll come off when you want them too. Orange/red RTV is the high temp stuff. I use a film, not an entire bead, on the flange. If you machine the manifold and have checked the head and it's fairly flat a thick film of RTV will ensure a good seal.

On some applications, use as T444E/7.3l PSD and all of the big block Ford/Chevy's we put together at the shop (as well as many other larger applications) I don't use anything. Just bolt a flat manifold to a flat head. The RTV is just insurance in case there is a small ding or low area.

How is the exhaust pipe hooked to the manifold? If it doesn't use a gasket I would use some RTV and anti-seize on the bolts/nuts. If it does use a gasket then use the donut/gasket with some RTV.

You won't need a lot of RTV, if it is squishing out all over the place you put to much on. You just need enough RTV to take up any variation might be left over, really it's just insurance.

No need to convince a machine shop (if that is who you are talking about) that it's necessary. Just plop down your manifolds and ask them to surface them. If anything just tell them you are going it for safeties sake. Good luck.
 
Thank you.
The exhaust is hooked to the manifold with like a ball and socket. I forget what they are called.
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Ill just use a little orange rtv.
I was talking about convincing my Dad.
Hes going to take them somewhere on Monday.

In the mean time I cleaned the battery, and removed all the O2s so I could put anti-sieze on them.
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If it's a ball and socket you can use some anti-seize just to make it come off easier in the future. The sealing is done my slightly deforming the "ball" into the socket on the manifold. Sorry I was thinking about a bit older application. RTV won't hurt, but it won't help either. Anti-seize or bolt up the exhaust pipe dry. Use anti-seize on all the hardware though.

Good move on gooping up the O2s, they can be a real nightmare to pull out after a few years of use. Especially in your neck of the woods, plenty of heat going in and out of that engine
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