Reuse or not: UIM rubber seals

[elgoathead]

The original seals on the upper intake manifold (1996 4.0 OHV) are molded to fit in the grooves around the runner openings.

My new gasket (Felpro) is a paper gasket with what appears to be some sort of sealant manufactured right on to the paper. This gasket does not fit into the grooves like the original rubber, it just lies flat on the mating surfaces.

Do I throw away the rubber seals and use the new gasket by itself, or use them both together?

My gut feeling is to ditch what was there and install the new one by itself.

The directions in the box make no mention of it except to be sure to avoid using a sealant.

Regards... Mike

 

[Dono]

There should be new o ring type seals in the kit. They should be replaced, but not with what you are describing.

 

[koda2000]

something about what you're describing doesn't seem right. are you sure you got the correct gasket kit? all the id information will be printed on the box. you should not reuse the old gaskets/o-rings.

 

[colintrax]

Never reuse gaskets. Like Koda said, I'd make sure that's the right kit. Doesn't sound right to me either

 

[2000StreetRod]

Plenum gasket

Your description matches the lower intake gasket. The part number for the lower gasket is MS95739.

Get the plenum gasket set. The upper gasket part number is MS90733.

 

[elgoathead]

Here's what I have.

http://shop.advanceautoparts.com/we...duct_valve-cover-gasket-set-felpro_19783648-p

Actually, this is the valve cover set. The UIM gasket is included in the set, that's why I'm replacing that as well.

The gasket pictured in the middle replaces the rubber o-ring style seals.

I double-checked; it is the correct application, confirmed by the vehicle listing on the box.

I see now that the answer to my question may be inside the box: The installation sheet states: "FEL-PRO PermaDryPlus gaskets have been developed to deliver permanent solutions to old problems. Permanently."

It is my understanding that the intake manifold gaskets on these engines have been known to have issues... perhaps this is a new and improved version that addresses these problems.

The fact that the sealing surface of the new gasket is much thinner than the originals is what prompted me to question it. I guess I should just trust that it will work, as I have experienced nothing but stellar performance from Felpro products in the past.

Thanks guys for taking the time to provide input... it is appreciated.

Regards... Mike

 

[koda2000]

Fel-Pro PermaDry gaskets are the bomb!

 

[colintrax]

I just did gaskets and used felpro. Mine looked mostly like what I was replacing. Which was felpro... Lol
But the upper intake should be those rubber o rings. Mine came with 7?? But you only need 3

 

[2000StreetRod]

fixed position gaskets

Sometimes the stock type gaskets pop out of their "seats" while installing the intake manifold and do not seal properly. It looks like the new ones prevent that from happening. However, make sure the total thickness of the new ones is comparable to that of the old ones. The gaskets shrink as they dry out with age and leak.

 

[Benjam]

Mike,

When they refer to fixing a problem permanently they are likely talking about the 4.0 valve cover leak that we have all come across many times before.

If you have a plastic plenum, which it sounds like you do, you need the o-ring type seals. If you're in a bind, it isn't the end of the world to reuse your current seals for a little while, but you may encounter vacuum leaks.

This is what you are after: http://shop.advanceautoparts.com/we...et-felpro_15780439-p?searchTerm=plenum+gasket

Hope this helps,

Benjam

 

[elgoathead]

I'll bet the plenum gasket is included in the valve cover set because the driver side cover is so much easier to access with the plenum out of the way. I have to wonder then why they provide a paper gasket with the valve cover set but offer the rubber ones when only the plenum gaskets are needed.

I went ahead and used the gasket provided. A short test drive indicates that it is working. We'll see if it holds over the long haul. It's not that big a job if I have to pull the plenum again and install the other kind.

Thanks... Mike

 

[elgoathead]

Did it work? Well, yes and no.

This gasket leaked big time, but not where I was expecting.

There are three slots (about 1/8" each) on the passenger side of my plastic intake plenum, each adjacent to a runner pair. That's where it sucked air. I put a dab of silicone sealant over each one; now she runs like the proverbial well-oiled machine.

What are those slots for anyway? I theorize that they allow air to escape when installing the plenum with the rubber gaskets.

I think I'll re-do it with the rubber gaskets anyway to avoid any future issues.

Again, I'm just not getting why Felpro would provide a part that cannot work without the installer having to do a work-around.

 

[2000StreetRod]

tabs & slots

On my SOHC V6 there are tabs on the O ring pair gaskets that match/fill the slots in the plenum. The slots help keep the gaskets in the correct position. Your gaskets are probably too thin to vertically fill the space where the slots are. To me that means that as soon as they dry out a little they will start leaking.