CNG Fillup

[Jaredny]

I've noticed lately on my cav that when I detach the CNG nozzle I lose a lot of natural gas, it finally stops but It just started to do this.

[Highmarker]

Re: CNG Fillup

Jared,

The check valve is staying open when the pressure drops from venting it on the filling hose. I noticed this once in my 2001 Cavalier. For me, it hasn't done it again. The check valve only allows flow in one direction, but if it gets stuck open, then it can let gas out. The problem might be temperature related, but might not. If the problem continues, I'd get the check vavle replaced.