Nellie's water temperature gauge has recently started reading 210°F when the IR temperature gun is reading 180°F. To say this is disconcerting is an understatement. Here's my temporary solution.
Yep, just cover the darn thing with a piece of paper.
Another anomaly has to do with the oil pressure gauge, it's reading about 5 psi low and the needle is quaking.
The Cummins 4BT-3.9M came equipped with VDO instruments. Among Nellie's spares is a VDO water temperature gauge. I suspect it's there because a former owner bought it while diagnosing a sender unit/gauge problem. The sending unit was at fault so the gauge became a spare.
I've ordered new water temperature and oil pressure sending units in the hope that they'll fix Nellie's problems.
P/N 360-009 VDO Oil Pressure Sending Unit
P/N 323-478 VDO Water Temperature Sending Unit
