Are the oil temp sending units for different brand gauges matched to the gauges? I had Faria Gauges in my old boat, but Gaffrig Performance in the new boat. Sending unit remained in the engine when I swapped it to the new boat.

While running today with the gauge finally hooked up, my oil temp was reading 320+!!!! I shutdown and pulled the dipstick, it felt and smelled normal. I run a oil t-stat so it usually fluctuates between 180 and 215.

Thanks for answering such a basic/stupid question!!!

I changed from VDO to Gaffrig/Livorsi guages with no proble EXCEPT the fuel guage. VDO uses a totally different resistance sceme than standard US fuel guages so I had to change the sender. Everything else came over A-OK.

I had a similar situation with a Stewart Warner oil pressure guage. The sender was for 80 PSI and I installed a 100 PSI guage. The sweep of the guage is the same for both so with the 100 PSI guage it appeared I was running like 90 PSI oil pressure. I installed an 80 PSI guage and the pressure was 65, which agreed with a mechanical guage. I later confirmed with SW that a 100 PSI sender was required with the 100 PSI guage.

I had a VDO sensor on my engine a Gaffrig/Livorsi guage. It made the guage work in reverse.

I think I'll splurge on the $ 20.00 sending unit to eliminate the stark terror that I felt when I saw 320+ degrees of oil temp!!!

If you still have high oil temp with a properly calibrated sending unit, you may have an overfill condition. The overfilled oil will aerate and heat up more than non-aerated oil.