Have you tried taking your suspect temperature sender out of the engine, and sticking it in a pot of boiling water? If it does not read 212F--exactly--you then have learned for sure that it is not telling you the truth about your engine temperature.
These are themistors, and a bad connection in the wire loop can add enough resistance to the circuit that the temperature reads quite far off in a nonlinear way. I just traced a problem with a high oil pressure reading to that cause.
My TMD22 runs at 180F at idle and 195-200 at sustained cruising speed of 2400RPM (7 knots). 170-185 is Volvo's spec for first opening of the thermostat , and 197-208 is where is it is wide open.
Solomons Island, Maryland.
---In amelyachtowners@..., <sailw32@...> wrote :
Mark, I for one agree , I wish I did not have a turbo, just another complexity , that is really not necessary . You brought up one other issue that I am dealing with , engine temperature . I had a new Volvo instrument panel installed a few years ago and the temp gauge ran hot like 230 F. The mechanic installed a 10 ohm resister I think, in the wiring to bring the reading down . Seemed very arbitrary to me , seemed to me a Volvo gauge should correctly read a Volvo sender without regulating the signal. So I have never had faith in the gauge and running hard 2500 rpm the gauge reads 225 F. , using a infrared gun at the thermostat I have had readings of 200 to 205 or higher . This is another reason I have ran slower to keep the temp. down. I clean the heat exchanger yearly ,transmission cooler, new impeller ,etc. I am not sure if I have an overheating problem or not , not sure what one would expect the temp to be at the thermostat , two different guns give me different readings and the gauge can't be trusted.
Its always something,