Hey guys
Need to know whether or not I need to put a sealant on the upper and lower intake manifold gaskets b4 I put it back on the block

P.S. you do need really "tiny" hands to get the lower intake manifold off

 

I put it on my LIM gasket when I replaced it, you don't want that leaking and having to be removed again.

 

I used a thin layer of gasket sealer on both the LIM->engine gasket, and the LIM->UIM gasket. No leaks yet.

 

Dont seal the UIM - LIM gasket, if you have a vac leak underneath of it shortly after repairing your car, it makes it harder to get to and can damage the gasket.

 

wait so you ARE saying to seal the gasket correct? and whats up impreza i ordered my new gasket and the shop says once i get this fixed that i'll be perfectly fine and in mint condition because i talked to the mechanic that was working on my car and he just told me he recommended that i get a friend who is good w cars do it cus they would charge a whole lot to do it. and what kind of sealant should i use?

 

sorry i wans't trying to steal your thread im just goign through the same thing but yoru a step ahead of me i haven't even popped hte hood yet cus its still at the shop and the gasket hasn't come in the mail yet.

 

i didnt use any sealant on my car and i have no problems after 2000+ miles. Just use the correct torque settings

 

Great...another consensus! Any other voices out there before I screw mine back on?

Frankly, with that 3-ply metal gasket, I can't see sealant on only the outer faces making any difference. Air could still leak through the middle ply.

 

permatex copper gasket spray... it makes it difficult to re-use gaskets, but seals really well

 

I typically use a *thin* layer of RTV on the Mazda paper gaskets.
This allows for easier removal, allows them to be reused, all slightly better sealing.
Don't use too much, or you end up squeezing some of it into the intake passages!

WATCH OUT WITH THE LIM -> ENGINE GASKET!
These usually have small, pin sized holes for the primary fuel injectors.
If you clog these holes, it will kill your idle quality.
Don't ask me how I know this. :P


-Ted

 

I'm going to use Hylomar on all the paper gaskets, but this is a funky triple-ply metal jobby. I'm sure you know what I'm talking about.

 

im going thru the same process with my S. i blew the TB coolant line that stems from the nipple on the rear iron. while i have the manifolds off to repair this line, i did alot of other work to the intake manifolds and 6PI system. im also redoing all the oil injector lines w/ PFA teflon hose since one of the lines broke. while its all apart, id like to convert the system to 2-stroke using the Rotary Aviation adaptor. and since i have easy access to the exhaust manifold, i also want to do a true-dual exhaust from the engine back.

but now for my question; what have you guys found to be the best way to remove stuck paper/composite gaskets?

i cant chip it off w/ a screwdriver, especially around the fasteners. i cant scrape it off w/ a single edge razor because it just slides right over the stuck gasket and shaves off a thin layer... plus, its akward around the studs, and behind the front cover and such. ive used the Permatex gasket removal spray before. it works wonders on the silicone sealers/RTV's; they soften right up and wipe away. however, paper gaskets are another matter.

you guys have any other tips or tricks to get stuck gaskets off?

my LIM-to-UIM gasket is stuck and in one peice. i cant reuse it by smearing a thin layer of silicone on though. i damaged the edges around the runners while porting it.

btw, i removed my VDI port valve in the UIM to ensure i removed all the aluminum shavings. but when i reinstall the VDI valve, does the tip of the shaft need lubed where it meets the bushing inside the manifold? if so, what is specified to be the proper lubricant for this application?

thanks
chris

 

Those are "reusable" and do not need any RTV or Hylomar.
The raised metal edge crushes for optimum sealing.


-Ted

 

If you have patience, I use a razor blade.
If you're lazy, try "gasket remover".
I know Permatex makes some in a spray can?
Watch out for this stuff, as it BURNS your skin!


-Ted

 

go to home depot and get a window scraping razor(painting section) it gives you some power and is also safe not to f#@& anything up

 

I have both a razor scraper and a hard unflexible metal scraper. Contrary to what you'd think, the razor scraper is pretty useless in removing old gaskets. The metal unflexible thingy works great. Then I clean it up with the razor.

 

I ended up putting a thin coating of Hylomar around the openings, but since Hylomar is non-hardening, it shouldn't affect the re-usability of it. I have no intention of ever finding out though

 

Be careful with that stuff - remember, you're scraping against aluminum.
I dunno what a "metal unflexible thingy" is, but it's gotta be harder than aluminum?

Most razors are made of steel, so if you get careless, you end up gouging the aluminum mating surface.



-Ted

 

I haven't damaged anything with the hard scraper yet. It just doesn't have a sharp enough edge to dig into the aluminum. On the other hard, using a razor scraper, it's hard *not* to scratch or cut the aluminum.

 

i managed to remove all of the gasket on the engine, the LIM, UIM and the VDI actuator. i bought some of the Permatex gasket remover spray. it doesnt work fast and doesnt penetrate fully. i just had to apply, wait, scrape and repeat. it didnt get EVERYTHING off, there was a thin film is some places that i was able to rub off w/ some 600 grit wet/dry sand paper.

another good thing i found was that the LIM-to-engine gaskets are now MLS. they are 3-ply w/ a raised bead around all 6 ports. its held together w/ 2 copper rivits. the surface sealer on the gasket layers are fluorine rubber coated. these are essentially like HKS head gaskets.

my only problem is that i have a vaccum nipple on top of the LIM which is sourced from the primary ports... where does this nipple connect to?