I always knew someday my intake manifold would crack, but Im not sure if today is that day. I think I may have a hairline crack between the base of one of the runners and the coolant passage.

I'm not sure if I'm losing coolant but I am getting coolant smoke on startup.(start up smoke seems to be problem w/ me).

I think the coolant could be sitting on the valve and being dumped in and burnt off on startup.

I havent heard of anyones intake manifold cracking gradually so im not sure if this is actually the issue. Does anyone have any other possible ideas or do you all think I hit the nail on the head with the diagnosis?

 

I'm guessing I got it right then if no one has any other suggestions.

 

I think you hit the nail on the head. My intake cracked slowly, it started off not being that bad and being driveable. I was doing a little sprint one night with my buddy and it blew wide open.

As far as the smoke, I never had that problem. My best advice would be to check the valley real good. When mine cracked it puddled up in the valley real bad.

 

i have an idea to test this, its basically a leak down test for your intake. I'll take a picture of what i made to test mine later. Basically what i did, is make an apparatus that will push in a regulated 20-30 psi in the intake with the engine stopped. On a completely sealed engine, there should be no leaks. However, with a crack you should hear and feel air coming out of the intake.

Hope this helps! I made mine out of PVC piping, its not hard at all to make

 

I think mine may have cracked differently than most/every other intake manifold. I fully checked the valley with a UV test. And it looks bone dry. I really need to pressure test the system.

I think mine may somehow be leaking directly into one of the intake ports. I replaced the intake gaskets not that long ago so I doubt its that.