checking intake gasket

[IndianaVX]

well people, im just about to roll over to what seems to be the ominous 63,000 mile mark. truck seems to be running fine. very little oil consumption. dont seem to get the mileage that i used to though. it seems that ive read in the past that the intake gasket can/might cause poor gas mileage. so my question is, how do i check? im thinking that a person sprays brake cleaner, or throttle body cleaner somewhere around somewhere, but im not sure where that "somewhere" is. and if its leaking, the engine revs, or sputters, again,not sure which.
can someone enlighten me? i did searches, and couldnt find anything, so hopefully, there will be pleanty of input for future vx'ers searching for the same answer.

as always, thanks in advance,

God bless us all, :)

David

[thedutchguy]

Just spray in everywhere, then at least your engine will be clean! :p :p

[Ldub]

That big silver (aluminium) thing under the plastic cover, on top of your engine is the intake manifold...
Remove the plastic cover so you can see what you're doing, remove the friction inserts from the plastic cover mounting pegs & re-insert into the mounting holes on the bottom of plastic cover.

Look at where the intake manifold connects to the heads...that's where your intake gaskets are.

Start your enging from cold (let it warm just enough to idle normally) & spray carb cleaner, starting fluid (ether, my personal favorite), or brake cleaner where the intake gaskets are & listen for any change in rpm.

Put it all back together & call Merlin for new intake gaskets.

[kpaske]

That big silver (aluminium) thing under the plastic cover, on top of your engine is the intake manifold...
Remove the plastic cover so you can see what you're doing, remove the friction inserts from the plastic cover mounting pegs & re-insert into the mounting holes on the bottom of plastic cover.

Look at where the intake manifold connects to the heads...that's where your intake gaskets are.

Start your enging from cold (let it warm just enough to idle normally) & spray carb cleaner, starting fluid (ether, my personal favorite), or brake cleaner where the intake gaskets are & listen for any change in rpm.

Put it all back together & call Merlin for new intake gaskets.
Just to clarify one point - what you are describing as the intake manifold is actually two pieces, sealed by a single gasket. I think the top part is called the "common chamber". The intake manifold connects to the heads in two places and uses two gaskets. You most likely will NOT have a leak in that "upper" gasket (between the common chamber and the intake manifold), but if you are thinking about replacing the intake manifold gaskets, removing the common chamber may make it easier to get to the intake manifold. The leak will likely be lower down, on one side or the other (probably not both), where the intake manifold connect to the heads (look for the edge of the gasket).

[IndianaVX]

ok, so today, i got down to it and sprayed the carb and throttle body cleaner down there by where the injectors are, and i could see tabs comming off from the gaskets, so i think im spraying in the right place, right?
so anyway, it is pretty grimey down there, and this stuff is bubbling like all get out, which is what i assume the "cleaning agents" (scrubbing bubbles)of the carb throttle cleaner. but i dont really hear any change in the rpms. but like i said, it is really grimey down there, and the rest of my engine is pretty darn clean.
i understand that there is little access down there, and can see how stuff and grime would collect, is this also maybe an indicator of bad gaskets??? the grime im talking about.....it does seem to be "oiley" grime.
i just want to take care of things as best i can. what do you guys think? again, i heard no rpm change, so what do you think
thanks
david

[IndianaVX]

ok, ill try again, read my post above too, if you will, and leave comments on it too....
NOW another question, is there a way of spraying on the "inside" of these manifold gaskets, the side facing the middle?? are there generally leaks on that side? am i just being paranoid? my mileage is getting pretty bad. i need to replace the egr gasket too, im thinking that it might be leaking since i have never replaced it, but have cleaned the egr 4 or 5 times. please respond to the manifold gasket questionat least, im not sure a person can see them coming from the center can we??

[tooldini]

I am gonna put in my second set of intake gaskets this weekend I hope. Each time there was a leak the vehicle started running bad. Just idling different and up and down once in a while then after some time it will be very bad running and won't hardly idle at all under 2K. My dad read that the factory torch specs for the bolts are not right and this seems to be causing the gaskets to go bad. I think he read this at a jegs website. I you want I can try and get the specs.

Jeff

[Tone]

Correct revised (lower) torque spec has been posted on .info (found using search)
13 lb ft.
Other specs:
Intake Manifold Fasteners: 16 ft. lb.
Common Chamber Fasteners: 18 ft. lb.
Throttle Body Fasteners: 18 ft. lb.

Put new gaskets on dry, the gaskets look the different top and bottom but they work fine either way. If you are careful, you will not have to replace the common chamber gasket but you'll want to test for leaks and have one in hand just in case. Same thing with fuel injector orings. I was flown out to LA to change them on a VX and we did it in about 2.5 hrs.

BTW: Supercharging does NOT lead to early failure of these gaskets due to heat - they are phenolic and can take much more heat than we generated although an serious overheated motor w/o coolant could prob. help cause it. Proper torque is key.

[tooldini]

Thanks for posting that for everyone again. My dad has the torchs at home I just didn't have them to post.

Jeff