1000hr opti over heat alarm??
225opti done 1000 hours. Just serviced. All water pump inc housing wear plate etc good. Impeller new. poppet valve replaced last year.
At Tickover the smart craft gauge reads 0.6-0.8 bar block pressure and the temp rises until over heat alarm Sounds. Lift RPM very slightly and the temp falls rapidly down to 36. Let it idle again and the temp rises up. The tale tale is good but not as strong as I would expect. Stat is good and water ways you can get to are very clear with no signs of crystallised salt.
Any other ideas.