I know that I have a vacuum leak around the intake manifold and plan to replace the gasket. Other than replacing the gasket and properly torquing the bolts, does anyone have a sure fire way to guarantee that manifold will not leak. I only want to do this once.

 

Make sure you clean up the gasket mating surfaces really good, and check all vacuum lines in the area.

Which gasket are you doing? Lower intake-to-engine, or one of the ones between pieces of the intake manifold? You should do them all while you're taking stuff apart in the area.

 

I am repacing both upper and lower intake manifold gaskets.

 

(since it looks like you hv an s4 in your avatar) you may want to replace the gaskets for the 5/6 pt. actuators also. (s5 is diff and doesnt use gaskets there)

 

I've heard that applying a thin coat of grease to the paper(?) gaskets allows them to be removed in one piece and reuesed. I haven't tried it myself, but I plan on doing so next opportunity I have.


http://grassrootsmotorsports.com/art...ease-its-word/

 

Are the 5/6 port actuators easy to remove and replace gaskets once the UIM is removed? Do they develop vacuum leaks frequently as well?

 

@ needRX-7 why would you want to reuse the gasket?

 

^having the gasket come off in one piece and not having to scrape the gasket surfaces makes it worthwhile. As for re-use, depends how long it's been.

 

So you don't have to buy another one .

The actuators are very easy to remove, you can do it without even removing anything else, it's just 2 10mm nuts each and they slide off the actuator arm. I've never heard of an actuator leak in particular, but if other intake gaskets are leaking, the actuators probably are too.

 

Ultra Black B) I put a thin coat on my gaskets when I reinstalled the engine back in May..

 

Mating surfaces must absolutely be completely clean of any and all old gasket. Dont even utter the words "good enough". Do that and you shouldnt even have to use RTV.
I do agree that while your at it you should replace all intake gaskets. Hell, I used to go as far as using that time to replace vacuum hoses which are easily accessible at that time.

 

I generally don't like putting rtv or silicone on intake gaskets. Oil or coolant is ok, but I don't like the idea of a silicone booger falling off and getting in the engine. Even if it's just rubbery silicone, there's a reason cars use air filters. In all reality, it'll probably just pass right through and go out the exhaust, but why take the chance when a clean mating surface and proper gasket will seal it like it came from the factory?

 

New gaskets and clean surfaces are all you need.

 

Stay away from rvt its a pain and looks like crap and always the chance of boogering in your motor, so clean all your surfaces and coat your gasket lightly with copper gasket spray like PERMATEX Copper SPRAY-A-GASKET Hi Temp Adhesive Sealant (if you soak it, it will mess up your gasket) and tape off and lightly coat your surfaces of the manifold too so if you ever need to take your manifold back off all you will need to clean off is the copper and some laquer thinners takes that right off.

 

have fun chiseling off the asbestos!

usually if the OE gaskets haven't been compromised i leave them alone. sometimes it can take upwards of an hour or more cleaning up one mating surface. if worried a quick coat of ultra copper(spray) will seal any minor imperfections in the surface.

original mazda gaskets suck to remove, but they did their job well. usually the LIM to the block and the 5/6th ports are the only ones that fail.

 

@ Karack no doubt about chiseling off the gasket. Got it super clean though and resealed with a new gasket. No leaks!

 

RTV by Permatex called "the RIGHT STUFF"..holds well..seals good.
comes in a Half size caulking gun type tube.

 

Rub a little bit of sealant on both sides of the gasket, will still get a good seal but helps make it easier to clean the next time you have the gasket off.

 

+1. i just use a little silicon