1990 535i Vacuum reading

[scott 4991]

I read this on the group.. not sure which car...

At idle 650 rpm = 8.5 inHG steady
At 1000 rpm = 10 inHG and steady
I held the RPM's at several levels and the vacuum increased with rpm's and held steady in each case with no fluctuations at each rpm.

I wanted to check my vacuum, and as close as I can tell I read 3 inHG at idle.

****** Is this to low? *****
Should I be looking into a vacuum leak somewhere?
*** What issues will I see if the vacuum is to low? ***

My idle is rock solid.

Also, as I increase RPM the vacuum goes down a bit, then returns to 3.

I have looked in the Bentley manual, dont see any reference to this.

Thanks for any comments.

sc