CRAP! Whats this sound like to you..Intake Manifold Prob

[Kdubslugga]

I just got done intalling my Cobra upper and lower intake, and it idles like crap now. Somethings definetly not right. I drove it around the block and when i have my foot on the gas it runs smooth but as soon as i let off the gas, it rides like crap. I can hear something leaking from the back of the Intake, it sounds like air and water leaking out, a bubbly sound. That leads me to think that coolant is leaking from the back of the lower intake, whould that mean theres a serious vac leak to? Whadda you guys think? Also its shooting out alot of thick smoke under idle, what could that be?

 

[jrichker]

V.A.C.U.U.M..L.E.A.K...

You may be sucking oil fumes into the intake manifold.

Here's a tip for doing intake manifold gaskets...

My favorite trick that saves time and effort is the stay in place gasket. Be sure that you scrape (don't use a wire brush) all the old gasket material off, then clean all the surfaces with acetone or MEK.

When the surfaces are clean, use weather strip adhesive on the head to manifold surface, and on the side of the gasket that mates to the head. Follow the instructions on the tube or can and when it gets tacky, press the gasket down on the head.

Clean the area where the rubber rails mount to the block in front and in the rear with more acetone or MEK and do the same trick with the weather strip adhesive that you did to the heads.

Coat the rubber seals and the gasket area around the water passages with lots of Blue Silicone gasket sealer and put it together. Wala! no leaks, and no gaskets that shifted out of place.

If you reuse the injectors from your old setup, a repair kit is available from most auto parts stores if needed. Coat the injector body "O" rings with oil before you use them and everything will slide back together. Take the other advice you got here and run with it.

 

[drgn5.0]

did you put rtv around the water ports on the cylinder heads?

 

[Kdubslugga]

no i didnt drgn5.0, i dont even know what that is. oh well, looks like ill be taking it all back off again

 

[dastang2]

since you have a huge leak, the computer is comprimising by dumping more fuel than needed, which smokes black and smells. either you left off a hose or you bent the intake gasket. check the oil for water

 

[drgn5.0]

you need to put rtv around the water jackets ( the holes that don't have valves in them) on the heads, and instead of using the front and rear cork gasket for the lower intake to block, you should put some high temp rtv on the block (where those small strip gaskets went) the whole length and let the rtv cure to cure 5-8 minutes and then drop the lower on.

hopefully someone has some pics on what i'm talking about or maybe i can find some.

 

[Jarod96Stang]

Is there a distinct whistle at all? if so, it might be your PCV valve...the plug inside is probably shot, hard and brittle...maybe thats the problem

 

[drgn5.0]

here is an old pic of my motor, the coolant holes are 2 on each head, on each end. i'd put some rtv on each lower intake gasket, to hold it in place around the ports. then put some rtv w/ a healthy amount on each water port, then put some like i was saying on the block, you can see the first area you need some in this pic, right behind the dist. hole where the blue stuff is left over.