ghost knock caused by A/C & ESMM?

petah · Post by **petah** » Sun Jun 24, 2007 8:28 am

anyone experience this with A/C and ESMM causing ghost knocks in closed loop? i find it weird all of these (except #4 datalog) were caused by turn on of AC. I have ESMM.

Car is a GReddy turobed RSX-S with ESMM and stock cat/exhaust.

I don't think it is bad gas, I have filled up at a different station and still getting some knocks in closed loop/very light throttle

all the datalogs are from the same datalog .. just cut it into little pieces to reduce the size. I don't have the second datalog but i was able to pick up the knock via flash of the CEL.

petah · Post by **petah** » Sun Jun 24, 2007 8:29 am

also, i did not experience this over the winter at all ... a/c was not used in the winter. gas used was either 93 or 94 sunoco.

Post by **Spunkster** » Mon Jun 25, 2007 10:06 am

Turning on the AC causes the engine to idle up. If it is picking up noise from vibration this makes snese as idleing up change the vibration resonance.

petah · Post by **petah** » Tue Jun 26, 2007 10:31 am

thanks! I'll keep an eye on it.