vacuum leak
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vacuum leak
My 86 F250 460 keeps burning the carb. gasket at the passenger side rear corner just above the EGR valve creating a bad vacuum leak. Does anyone have an idea where all that heat is coming from? I know there is alot of heat involved with the EGR but to Burn the gasket like that? Any info would be great
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Originally Posted by JWH2
My 86 F250 460 keeps burning the carb. gasket at the passenger side rear corner just above the EGR valve creating a bad vacuum leak. Does anyone have an idea where all that heat is coming from? I know there is alot of heat involved with the EGR but to Burn the gasket like that? Any info would be great
Since nobody seems to be answering you ill take a stab at it. The EGR (engine gas return). The exhaust from the heads onto the top of your intake and back into the motor. Your exhaust I would imagine is nothing short of 200 degrees. You might try some heat tape or making a heat shielf with some sheet metal. (bend by hand). I would probably try making a heat shield of some sort. Or ask your auto parts store if there is a high temp gasket made.
Posting Guru
Joined: Apr 2005
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From: Hawkeye Country
Simply fix is to remove the EGR completely and throw it across the yard, thats what I did. Otherwise a tougher gasket, or heat tape may help.
Off topic, I always thought EGR stood for Exhaust Gas Recirculation
Off topic, I always thought EGR stood for Exhaust Gas Recirculation
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Originally Posted by jimbo beam
Simply fix is to remove the EGR completely and throw it across the yard, thats what I did. Otherwise a tougher gasket, or heat tape may help.
Off topic, I always thought EGR stood for Exhaust Gas Recirculation
Off topic, I always thought EGR stood for Exhaust Gas Recirculation
o well doesnt matter we know what we are talking about!
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Joined: Jan 2001
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From: Virginia
Usually a gasket will not hold because it's not supported correctly. So I would look at the area where it's burning out, and see if it's eaten away or damaged. If the gasket is not pinched in there tight, it's not going to hold.
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Hey thanks for the replies and yes I know what egr stands for, but the problem is the truck runs at a fairly regular 200 deg.,installed a mech temp.gauge and that corner gets hot enough to partially melt the grommet on the gasket,I was just wondering if anybody else had run across this.Somebody said back pressure can cause ths? Motor has 20,000 on factory rebulid??
Cargo Master
Joined: Apr 2003
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From: Too close to Houston
I'd check Franklin2's suggestion and make sure the gasket is properly clamped. A loose fit could result in an exhaust leak under the EGR plate. That will heat the plate much more than the normal low EGR flow rate.
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More Turbo
Joined: Aug 2005
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From: North Georgia
had the same problem on my 86 460 and what I discovered was the two surfaces were no longer flat anymore and would not make a good seal. The problem is the heat as you have said and the metal deteriating away in that thin area. had to change intake manifolds to fix it. I suggest getting rid of all the smog stuff and going with a aftermarket intake. Mine runs like a top now with no leaks. hope his helps scott.
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From: Niceville, FL.
You may be using the wrong gasket. My '83 F350 w/460 uses a thin gray gasket (as OEM) with no problem. I've never tried the thick brown gasket (the one with grommets) that was also included in the carburetor rebuild kit.
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I had the same problem on my '86 460, just replaced gasket today. I had the spacer machined to flatten/smooth it out, i really hope it holds. dont wanna replace manifold. 
Sounds like this is a cronic problem w/these trucks.
Sounds like this is a cronic problem w/these trucks.
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