Hey bro- I need some serious help. I did a boost test and the car wouldnt hold pressure because it was bleeding off at the breather on the end of the valve cover.
What is the reason for this? I talk to some others and they all dont know why its doing that. I did the test on a cold motor. Thanks.

The car makes plenty of boost, I am just trying to make sure there is no leaks so the AEM can properly control it or I'll have infinite boost from a leak.

 

you should do the test with the engine warm. the rings on the pistons will help aleviate the boost leak issue through the valve cover. you do the cylinder leak down test this way also. if it still leaks, then either you have a failed ring land, burnt piston, or some other bad demon...good luck.

 

If its a failed ring land, I would be blowing smoke all the time right?. I dont believe it would be a burnt piston becasue I have been running the car rich after the motor was running 30 miles or so. It was a little lean before when the motor was 1st reinstalled but I was never getting on it becasue it was a new motor.

I will try the warm motor. The car makes plenty of boost and runs fine so I am hoping thats what it is. Thank you

 

not necissarily. i had a small hole in a piston in another car and i wasnt blowing smoke. i would try the warm engine and retest first. i would also do a compression test as well just to be sure.

 

sometimes where you stop the motor, the valves for a cylinder are left open and it leaks through, try tapping the starter to move the crank a little or just cover the breater with your finger.

 

/\not recommended to just "cover" the breather hole. the pressure will have to go somewhere. it will likely want to comprimise the valve cover gasket. you also may want to start on TDC just to make sure that it is only #1 cylinder that is getting pressure. no other cylinder should be accepting your "boost" test.

 

you only have to cover it for about 3 seconds to listen for leaks from elsewhere and let off. as long as you have a regulator on your tester and set it for your max boost i can't see the valve cover gasket blowing. i've done it numerous times at 23-25 psi without a hitch.

 

I am hoping its just that the motor was cold. I have forged internals so I am a little concerned. I'll be checking it this weekend unless. All the input is much appreciated.