159 2.4 20007 plate
19,500 DPF/EGR by
AO Silver Member
Join Date: May 2009
Location: United Kingdom
Something to compare with: I have spent some time doing various tests on my sons 147 1.6TS as that suffered from fluctuating and low temperature readouts on his dash mounted gauge and ineffective heater.
For an ECU temperature between 60 - 82 degrees the dash mounted gauge reads about 8 - 10 degrees high.
For an ECU temperature of anywhere between 82 and 98 deg.The dashboard gauge on his car is rock solid at 90 deg. I couldn't get it above 98 deg as the fan kicks in at that temperature. I could have disconnected the fans but didn't want to risk cooking the engine.
In normal road driving, stopping at lights for short periods and pausing at roundabouts there is lag in the thermostat and the ECU temperature reading fluctuates between 84 and 96. Stop / start town driving there is the same lag but temperatures fluctuate between 90 - 98 at which point the cooling fan cuts in.
Before replacing the thermostat the ECU temperature in normal driving (open road with occasional traffic lights or roundabout) the dashboard gauge was reading between 80 and 90 degrees but mainly at the lower reading; ECU temperature being between 70 and 80 degrees.
The old stat passed the top hose test of sudden rise in temperature but was proven to be opening early. It did not have any temperature markings on it.
The new thermostat is from Eurocarparts and is a Calorstat. It has been fitted for 2 weeks and is still working well. The heater now gets hot rather than warm and quickly, it will now actually clear mist from the screen and side windows.
Different sensors and the manufacturing tolerances on the dash mounted gauges may not give these readings!
Last edited by kandlbarrett; 18-01-12 at 21:59.