intake manifold sealant

[85stanggt]

Sorry for bumping this 1+ year old thread. Can't believe I bought these Explorer gaskets over a year ago. Finally moved and now the car is puking coolant right after I replaced the clutch quadrant, so I have to replace these gaskets in order to drive it.

Don't do it. Follow the instructions FelPro gave you on the paper that's in the box with your gaskets. Those
end seals are designed to be installed dry, and they work very well. A small dab of sensor-safe silicone at the
corners is all you want.

Any gasket is designed to be a seal, therefore using RTV on one or both sides is stupid. The gasket is the seal, it doesn't need RTV to seal. You either use the gasket or the RTV, not both. This goes for any gasket. Never use RTV on head gaskets or the intake side gaskets. As already mentioned, only a small amount in the corners to seal the two gasket together.

For the regular paper gasket used for the water pump and timing cover, I would use grease on both sides , just enough to wet it out, will seal just fine, and will allow easy removal in the future. Something I learned from my dad 40 years ago.

I'll open the box and check out the instructions. But I DO NOT want the end seals leaking. I did my current Felpro 1250s with the RTV in the corners and the cork gaskets leaked within a year or two. I absolutely hate leaking gaskets that make a mess of the engine.

Sounds like some strong opinions to keep the rtv in just the corners of the Explorer end seals. Hear me out with this, but my experience with my BMW is that the rubber gaskets will be good for 20k miles before they get hard from the heat and start seeping, hence a thin coat of RTV keeps the gasket to block interface sealed. Maybe that's just those gaskets and the Explorer end seals are different material. Do these Explorer rubber end seals remain pliable and seep free?

[WilliamCapri]

In my minimal experience, RTV to keep everything together is necessary. The block is iron, the intake manifold aluminum. It is guaranteed that not only will gaskets be stressed, but they will be pushed around. I had one pair get pushed completely out with RTV in the corners only. My latest round was with the Felpro rubberized cork gasket with RTV on both sides. It has been in place for about 3 years now with no problems.

[jessesandy]

Used to be a sealer called Super Tacky. Seals great but it can be tricky to use since it works like a rubber/contact cement.
Any shifting or sliding or re-positioning of the parts is very limited.
On the other hand, the ends won't slip out of position during assembly.
I think it's called High Tack now.

Always avoided RTV in the past, but there are a lot of new products since the olden times. (The 1900's)
I did an oil pan with Ultra Gray three years ago and so far, no leaks.

[JACook]

With all due respect to BMW, the silicone end seals that come with the FelPro set are in a different league,
and not just because of what they're made from. There's some serious engineering went into those seals.

It never ceases to amaze me how people become attached to stuff. Despite major advances in sealing
technology over the past decade, people still cling to the comfort of the old ways. I suppose it's not too
hard to understand, what with notable failures like the FelPro PermaSeep 1250s, but when you're working
with a well engineered gasket, you need to resist the temptation to 'help' them by adding sealer where it
should not be.

I bring all this up because today I spent about an hour removing large quantities of the ironically-named
'Right Stuff' sealant off the gasket faces on a GM 4.3 V6 lower intake. For those not familiar, the intake
manifold gaskets on this engine are designed to use no sealer, other than at the end rails. And yet...

Despite (or more accurately, because of) using mass quantities of the stuff, the intake still leaked coolant,
resulting in overheating and a cracked head ('cause that's what these GM 4.3s do when they overheat...).
BTW, the FelPro 98002 intake gaskets for this engine are Impressive. And yes, this one still uses the silicone
beads on the ends. ;-)

[gr79]

People will aways feel a need to dress a gasket with something to keep it in place during assembly or help it seal.
Like cooking or ordering food. The never plain hamburger. Condiments, spices, cook time.
The need to change focus to a plain, simple, important area task on complex machinery.
Being comfortable and confident without overkill. Believe, trust. For sure should not guess if possible.
Always will be the concern about will it...? possibly causing more work or even being stranded on the road.

Using old tech from past experience may work, but universal procedures do not apply to everything.
From parts counter side, most customers want to save money, time, may not know proper procedures/materials.
Permatex Indian Head shellac was popular and still around.
Purchase correct items, follow product package directions, and Ford shop manual instructions/procedures if any.
How much sealer to apply (if any) varies, unless stated in shop manual. Film, bead size, app. pattern.
Surfaces have to be clean and undamaged.

Different materials are used for different versions, generations of engines, trans.
Duplicating correct factory combos and patience can be a challenge.

Say, for example, the intake manifold end seal on the GM Vortec 4.3 V6.
Seen 'em new (mostly LU3), fresh from the factory, maybe only hours old since assy.
Noted grey sealant, nothing else. Manifold to block. I pulled on some of it that was squeezed out. Silicone.
But what brand was it? How long did GM let it dry/cure before assy? How much was used? How much error was allowed?
Could something else similar be substituted with good results?

McCord supplied side intake gaskets on the Ford truck engine line i worked on back in the 70's.
What brand can be used now?
Do autoparts stores have them? Dealer? Obsolete?
Felpro prob more common aftermarket than oem.
In 2000's, Victor Reintz was a head gasket brand we had in the GM truck engine plant parts inventory.
Now they would make the real thing, but is it dealer only? Harder to source that brand aftermarket.
Lots of oem do not do aftermarket with their name on the box, so have to settle for whoever.
The parts may or may not be the exact same thing from auto parts counters.
Dealers usually do have the exact item thus the high markup. May luck out at a chain auto store.

Did the 7.5 rear axle cover on my Ranger.
Paper felpro gasket #1 with skin of black rtv to hold it in place- failed, leaked.
Paper felpro gasket #2 dry- failed, leaked.
Black RTV only (like factory did)- bead per shop manual procedure and package instructions- winner.

A few normal sealing products i keep on hand:
-Black RTV says wait till skinned then join.
-Permatex Ultra Grey says join immediately to squeeze out, allow 1 hr dry, then final torque.
-Permatex Permashield gasket dressing/sealant says allow solvent to evap, then assemble.
Blue in color like Hylomar, it never dries. Stays sticky, seals well, removable, messy.
Apps- T-5 shift tower plate, one side of the thermostat gasket to hold it in place. No leaks.
-Permatex Indian Head shellac- did use some on a core/freeze plug. No leaks.

[4idfox]

I will never use a gasket at the front and back of an intake manifold again. The last few engines I have assembled I have used a couple liberal beads stacked on top of each other. The product to use is Right Stuff by permatex. It will never leak.

[erratic50]

I've had good results with high-tack on gasket to block, RTV in the corners. Used 96 Explorer gasket set.

Back when it was stock, I had an EGR valve stick one time-- the motor sucked the rear gasket into the motor! Grr!

[85stanggt]

Don't do it. Follow the instructions FelPro gave you on the paper that's in the box with your gaskets. Those
end seals are designed to be installed dry, and they work very well. A small dab of sensor-safe silicone at the
corners is all you want.

With all due respect to BMW, the silicone end seals that come with the FelPro set are in a different league,
and not just because of what they're made from. There's some serious engineering went into those seals.

I did look at the instructions in the box the other night after I posted. It's a generic sheet for valve cover, intake, and other gaskets. However, in each section, it boldly stated in large lettering to install the silicone gaskets dry. And now I see what you were saying. I will thoroughly clean the surfaces, install them dry, and only add the Ultra Gray in the corners. I will also install the intake gaskets totally dry. Their material has an interesting consistency that feels like it will really stick and seal. It's not paper like the cheap Felpro set.

And no, the BMW gaskets suck. They used to make them from Buna rubber, which hardens and then leaks. Supposedly, they figured out that Buna is bad on a car with 108*C operating temp, so they went to Viton. Not sure I believe they actually did. But my E38 doesn't leak a drop now after I did the timing chain guides and used a film of Ultra Gray. I love that Ultra Gray stuff -- seals, but comes off without too much effort.

You know that I'll post back here if those end seals wind up leaking

Probably won't get time to the job until next week, though. I want to drive it so bad.