1994 OHV Intake Manifold gasket

[bn6339]

Hello,

Ive searched many threads to see if there are any hints/ideas to avoid leakage when installing a new intake gasket, but I havent really found anything definitive. I purchased the newer one-piece from Ford, as the consensus for this application seems to favor OEM . My questions are:

1. The factory manual indicates areas to seal the gasket to the block/heads, then the intake manifold to the gasket... im guessing just the gasket would seal the joints between the head and intake passages (ie dont use RTV on the coolant passages?) IS the factory method enough RTV, or is there something else I should seal?

2. Ive read a couple threads which stated the lower intake manifold torque sequence is wrong as published in the Ford manual...can anyone confirm/deny this?

3. Any other ideas/issues I should consider? This is my first 4.0, and Ive already removed enough to start seriously attacking the manifold itself....If anyone can link me to a writeup, thats also cool....thanks!

 

[BRUTUS_T_HOG]

a light coating on both sides of the gasket for the coolant passages helps prevent leaks.

then just a 1/4inch glob of RTV at the 4 corners where the heads meet the block.

 

[cr_the_machinist]

The lower intake manifold gasket is pretty easy. I'd recommend using the two piece gaskets rather than the one piece. The one piece gasket can cause tolerance and seating issues between the heads and/or block (front and rear seals of the valley). I think that opinion only goes for if you have had the block surface milled and trued or if you have rebuilt heads on you truck (that have gone through the same process). I used the two piece on my rebuild 15,000 miles ago with no problems what so ever. If you do go over to a two piece set up, buy a tube of rtv sealant. If the manufacture gives you one, its pretty much a joke. Makes you think if they're rationing the stuff. The more the merrier in my opinion. I believe the torque specs are 15ft/lbs.

Just looked in my tech manual..... it's 18 ft/lbs.

The torquing sequence can be found here at the bottom of the page..... http://www.therangerstation.com/tech_library/4_0_Page.html

 

[bn6339]

The lower intake manifold gasket is pretty easy. I'd recommend using the two piece gaskets rather than the one piece. The one piece gasket can cause tolerance and seating issues between the heads and/or block (front and rear seals of the valley). I think that opinion only goes for if you have had the block surface milled and trued or if you have rebuilt heads on you truck (that have gone through the same process). I used the two piece on my rebuild 15,000 miles ago with no problems what so ever. If you do go over to a two piece set up, buy a tube of rtv sealant. If the manufacture gives you one, its pretty much a joke. Makes you think if they're rationing the stuff. The more the merrier in my opinion. I believe the torque specs are 15ft/lbs.

Just looked in my tech manual..... it's 18 ft/lbs.

The torquing sequence can be found here at the bottom of the page..... http://www.therangerstation.com/tech_library/4_0_Page.html

I agree with your assessment regarding the one-piece vs two piece, because I'm familiar with GM 2.8 engines, which have a much steeper intake/head mounting surface...which effectively limits machining the heads, otherwise proper sealing is impossible.....I'm using the one piece only because the heads are original, if I need to replace the head gaskets, I may just spring for a lower mileage 4.0.....thank you very much for your help, this really saves me a ton of work....

Thanks for the link!!

 

[Ranger44]

I think the torque sequence shown is wrong. Tightening from the outside in just doesn't seem right. I can't remember who posted, but with using the single piece fel-pro gasket and a modified torque sequence......they have had success. The modified sequence just started in the middle and alternated on the way out instead of starting on the outside and alternating inward.

 

[BRUTUS_T_HOG]

I think the torque sequence shown is wrong. Tightening from the outside in just doesn't seem right. I can't remember who posted, but with using the single piece fel-pro gasket and a modified torque sequence......they have had success. The modified sequence just started in the middle and alternated on the way out instead of starting on the outside and alternating inward.

agreed.. when tightening anything down always start in the middle and work your way out.

when loosening start at the outsides and work in.