Thanks for reading. I recently, did a leak down test to pinpoint why I'm having low compression. The way I did it is, I pulled all the valve cover and all the spark plugs off and connected a 125psi air hose with a guage to cylinder in question. I also put the no.1 cyl at TDC but I'm a little stumped cuz air is coming out of the tailpipe and the no.2 sparkplug hole. I mean, I know why air is coming out of the tailpipe, cuz of Ex. valves not closing properly, but I cant figure out why air is coming out of the second cylinder. So, my question is am I doing the leakdown test incorrectly?

 

if air is coming out of the #2 cylinder when you are filling #1 then that tells me you have a busted headgasket.. If air is coming out of the exhaust and you are SURE that #1 is a TDC (arrows pointed up) then you have something wrong with the exhaust valves.

 

what were your symptoms or reason for doing a leakdown?

 

I bought the car with a misfire in cylinder 1.

 

look for bubbles in the radiator neck. Look at the coolant and oil. Also look at the plugs. What color is the exhaust ? What does it smell like ?

What are the compression and leakdown numbers ?

 

0 psi in cylinder 1. I had 210 psi in 2,3 & 4.