DieselJD,
My thoughts exactly. It does not seal water, or mixed air/fuel. It does seal oil, of a sort--It keeps debris from the valley, but its not like the oil is under pressure in the intake sealing area.
Call me a rebel, but just because "they" say it, isn't good enough.
Of course if it leaks what is the worst possible outcome...worst case you have to do it again, it doesn't run quite right. If you have a turbo, your boost isn't what it should be...its not like a gasser where your air/fuel ratio is important. I'm speaking ignorance here...what IS the worst case outcome if the intake gasket fails on a 6.9/7.3??
Woah there cowboy!!
These days I'm mostly lurking here, but only jump in when I feel it's really important. This is one of those days.
You're wrong.
Firstly, the intake gasket(valley pan) is only meant to be used once. It
is a compression gasket much like the head gasket and once compressed, is ruined.
Secondly and more importantly, it does seal against coolant/oil. In between each intake port, there is a 1/2" hole in the head which is continuous with the coolant passages in the head(originally part of the casting process). The valley pan seals this area off. If there is the slightest leak, then coolant will drain down into the valley and be in the oil, and I don't need to talk about what happens when you get coolant in the oil. On the later 7.3 heads. some of these passages were blocked with plugs, but I understand they weren't reliable, and it is still recommended that the valley pan be re-used.
lastly, it does also seal around the intake ports, and if your engine can pull air via leaks here, this would be unfiltered air, and especially if you have a turbo, then you would have boost air leaks to the cylinders. The result of this could be boost in several cylinders, but maybe not in others where there is a leak, and thus those cylinders would be running much hotter than the rest(less air going in) and since you only monitor average boost(at the intake hat), and average exhaust gas temp(at the outlet pipe), you'd never know that those particular cylinders were overheating.
It is only my opinion, but I say this is a very important gasket. I cannot see how you can remove one, and not do damage. Once is has been torqued and compressed, it should be thrown away, and use a new one.
The consequences are not worth the $50.
Zigg
