159 Engine Temp
From a cold start my 159 takes about ten minutes to reach a level 90 degrees on the temperature gauge. No problem there. On another day, again from a cold start, if I put the heater on when the gauge hits between 70-80 degrees, it then takes a lot longer to hit 90 degrees. When it does hit 90 eventually, it drops back to 80 or so degrees when it should be running at a level 90.
I am assuming there is a thermostat issue but need to know if there is anything else I should check. Today from a cold start, I let it hit 90, then put the heater on, and the temperature dipped towards 80. It took a few minutes and then it was back at 90 and remained there. The thermostat with housing is £120 and a right pain to fit. Before I contemplate this, are there any checks I can do to isolate the problem ? Thanks.