Suction Gauge Problem

[n824rv]

I just recently discovered a problem with my 1" suction gauge this past weekend during an engine run. I noticed at below 1300 rpm's the needle would just spin around the gauge. At around 1500 the needle would stabilize around 5 psi. But would not go down to zero when engine was shut down. My guess is a bad gauge. But would appreciate any input if there may be a bigger issue that I should investigate. Thanks

[osxuser]

The biggest issue is that you use one of those 1" gauges. I don't like them at all, they fail, rotate themselves, the range markings have rotated on my before as well. I'd just as soon get a nicer 2 1/4" one, thats what the older Cessnas (including my pop's cardinal) use with no problems .