So I'm playing around with my Scan gauges that I finally made pods for. I have a question on vacuum. I'm pulling around 10.2 mm/hg (or is it in/hg) at idle. I noticed my friends SRT-4 pulls around 20. What is the normal vacumm at idle on an L36?

IIRC, you should have less than 5" at full throttle and around 20" at idle. Check your lines and PCV.

Turn on The Weather Channel, as barometric pressure does have a small effect on NA engines.

At WOT I'm pulling 0 vacuum

Every car pulls 0 vacuum at WOT, unless you have boost from a super or turbo charger, in which case you will have positive pressure.

Ok just making sure because colin had a number. How is my idle number?

Can't answer without knowing the units of measure. There are inches Hg, mm Hg, PSI, and more. What units is your gage measuring in?

Vacuum diagnositics:

• Average, steady readings between 15-22 inches Hg (normal readings for a 60° V6 engine may be lower, i.e., 12-16 inches Hg) Possible Cause: Normal

• Low but steady, between 12 and 15 inches Hg Possible Cause: Leakage around piston rings, late ignition timing, or late valve timing

• Needle fluctuates or drops between 1 and 2 inches Hg at idle Possible Cause: Burned or leaking valve or spark plug in one of the cylinders is not firing

• Irregular needle drop between 1 and 2 inches Hg Possible Cause: Sticking valve, intermittent spark plug misfire, or rich or lean air/fuel mixture

• Normal at idle speed, but excessive vibrations at higher rpm Possible Cause: Weak valve springs; valves sticking in guides

• Excessive vibrations at idle speed, but steadies at higher rpm Possible Cause: Worn valve guides

• Excessive vibrations at all rpm Possible Cause: Leaky head gasket

• Needle oscillates slowly, or drifts between 3 and 9 inches Hg lower than normal Possible Cause: Intake system leak

• Normal at idle speed, but drops to near zero and rises to lower than normal Possible Cause: Restriction in exhaust system

If it'* in PSI, then there'* nothing wrong. 10.2 psi = 20.7672 inHg, which is a perfectly normal reading at idle.

Ah yes it is PSI okay all quite on the western front.