Ive had the intake manifold resealed twice in the last year with no luck. The second time I did it. Totally cleaned the surface off. Roughed up the back and front of the intake/block mating surface. I used regular rtv sealant as recommended. The car sat 4 days before I started it up and now its leaking from the front and back. Its the same spot in the back(near where the EGR tube used to be) so Im guessing the intake manifold is warped. Anyone have any other good techniques? Ive tried most of the tricks. This time Im going to buy another intake and take it to a machine shop to make sure its flat.

 

WTF?? What kinda sealant are you using dude??? You need to buy the FELPRO Intake gaskets FEL-1284 and then get yourself some COPPER RTV Sealant and use that $hit on the front of the back of the intake! There's no WAY IN HELL that $hit will leak if you do it right!

 

How thick a bead did you put on the rails? I use at least 1/4".

I use this method all the time on my Mustang and haven't had a problem yet. The cork gaskets included just get thrown in the trash.

 

the ones my buddy and i have done, weve cleaned the surfaces w/ paint thinner, then used scotchbrite pads on the rotary tool on all the mating surfaces, then used black rtv. you want to let the rtv 'glaze' just a little bit before you lay the intake down. and its very important to lay the intake straight down on the block and heads and get it right the first time. its helpful to have an extra set of hands for this.

 

Dude you only need a bead about the thickness of a pencil... Either way 1/4 should be fine too! Don't know what your doing wrong.. How do you know that the intake is leaking and not something else?

 

As 93turbo5oh mentioned, getting it set down correctly in one shot is very important. If you have to slide it around to get it right, you're done. Take it off, clean off the RTV, start over.

What helped me was a piece of pencil in 2 of the holes where the intake bolts down in the block. Once you're ready to put the intake back on, these will align it for you.

Also, I use the corner of a file to score some deep X's on the mating surfaces, along with some rough sand paper.

It's been about a year since I did the repair this way and so far, no leaks.

 

Two words (Right Stuff), made by permatex i think, comes in a black can.. best damn stuff ever made. lay a bead with it about the size of a pencil.. That is all i use on them. have used it on about 50 cars now and none of them have came back leaking yet.. Just my .o2

 

Another vote for "Right Stuff" The stuff is truly AWESOME!!!!!!!!

 

i am thinking my IM is warped? I used the copper rtv, and the front is ok, but the back is seeping. I am getting a little peod here. I looks like someone fixed it before, because everthing wasnt routed like the factory did, like the TB lines.

I am gonna say stay away from copper, and use something else, i dont know what though.

Have you checked the manifold for straightness? All you need is a straightegde. I am gonna do that if i pull mine off again.

 

The original guy(my friend) that did it used copper RTV sealant. We let it sit for 24 hours. It leaked as soon as I started it up in the back. 2 weeks ago my clutch went out again. I had to wait for a new one to come in and wasnt sure if the old one had been oil soaked(turned out it wasnt). I pulled the intake to be safe. Cleaned everything off with a razor and a vaccum cleaner. Wiped it down. Roughed up the mating surfaces with a file and the tip of a pick. Used black RTV sealant as recommended to me. I torqued it down as the Haynes manual said(inside out)and let it sit for 4 days while the clutch finally came in. I had to drive the car to my friends house. When I got there, there was oil leaking out the front. We pulled the transmission and you could see again it was leaking right under where the EGR tube used to be. I tried to wipe it and cover it with sealant for the meantime, but of course it didnt help.

Only things I can think of is I might of set the intake down too quick and torqued it. I had it pretty much dead on, I might have had to slide it a couple mm to get the bolts in. I guess thats where my mistake was. Ill try that Right Stuff this time.

 

I have also had a difficult time keeping my intake sealed, but always at the back of the intake.

I used the GM stuff and it definitely isn't working.

So I think I am going to try some of the stuff suggested above next time.

 

Go to a GM dealership and buy some of their grey seaant.. It works really well. Put a nice thick bead on a CLEAN surface. Let this set up for 10-15 minutes and then like others mentioned, carefully set the intake down, and do not move it back and forth..

You do not need to let the car sit 24 hours or whatever.for the sealant to dry. That is a huge BS myth.. Put it back together and drive it..

I see you mentioned where the EGR tube used to be.. If you removed it you should be ok, because the tube used to heat up the sealant and you would usually see it leaking from that area. bend the EGR tube away from the manifold as much as possible.

Even if the intake was warped liek you clain, the sealant should seal it.. Sealant does not care if the surfaces are angled or not as long as the bead is thick enough... You would most likely have an oil consumption problem though from leaking intake gaskets at the ports..

Quality sealant is the key.
Put a small bead at the end of the flat surface where they meet the head on each side(front to back bead), and then another long bead along the block lip.(side to side bead)

 

Stay away from these awful things!!!!!.. You can lock a motor up in a heartbeat or spin a bearing from the fibers even a minute amount getting ointo the oil system..

 

Two mistakes here. Don't ever, ever, use scotchbrite pads on a rotary tool or in any other form to clean parts where the bits might fall into the engine. They are engine killers.

You don't need to let the RTV "skin over" it works best on an absolutely clean surface. I have been doing this my entire adult life (I will be 35 this year) and I have never let it skin over and I have never had to do one twice. Good cleaners for this are brake cleaner, (not carb cleaner) electrical parts cleaner, or denatured alcohol. You want to clean everything at least twice to get all of the oil that you can out of the pores of the metal. Sometimes I use a punch to create a series of "divots" on the china walls (Front and back walls of the block and the bottom of the intake) to help hold the RTV in but it isn't really necessary. You want to use enough so that you get "squish out" of the bead when you put the intake on. Usually between 1/4" and 5/16" bead will do it. I use Permatex "Right Stuff" or GM sealer P/N 12346286 (They are both the same stuff in different forms). Another good one for this type of work is Saturn P/N 21006236 which is a "Three-Bond" product. I try to let the stuff dry for awhile before running the engine but in most cases it will be cured by the time you get the engine back in a condition where it will run. Especially if you use one of the sealers noted, they are all very fast-curing and will start to skin in about 5 minutes.

 

Noooooooooooooooooooooo!!!

Never get Scotchbrite near an open engine. The particles that come off are microscopic abrasive that will damage the engine. Many of them are so small that the filter won't catch them and they continue to circulate, causing damage on each pass.