Does my stat need replacing?
Up until reading this forum, I've always thought the behaviour of my temperature gauge was normal despite it appearing that the car runs quite cool, assumed that was normal for a TS engine.
In normal driving it's unusual for the gauge to get above 60, and a morning drive to work it barely registers on the gauge. The heater also doesn't kick in until the gauge lifts above 50 so leads me to think the gauge is reading correctly, just the engine is running cool. In heavy traffic the gauge will slowly rise before the fan kicks in at about 95-98. Once moving off into clean air and free flowing traffic the temperature drops as the radiator does it's stuff.
It's been like this since I brought the car over two years ago, and it's been serviced twice at two different indies and neither raised it as being an issue. Although I guess it's feasible they didn't run it long enough to notice this.
So do you think I need to replace my thermostat? After reading extensively on here sounds to me like mine is well and truly stuck open.
On another note I've recently noticed on two occasions that the fan doesn't appear to be working as the temperature has been rising higher than before. On one occasion whilst queueing for the Dartford Tunnel it got dangerously close to the red, causing quite a bit of stress. Fortunately I got through before it hit the red and as soon as got moving the temperature dropped.
Since noticing this and for a few other reasons I've invested in an EOBD interface and both Digimoto & Gendan's engine check software. Both are showing that I have amongst others a P0115 error which I guess is the cause of the fan not working. I believe this indicates that I have a faulty temperature sender some where or possibly faulty wiring.
So my current plan of attack is to replace the thermostat and the temperature sender on the thermostat. Is this likely to cure both problems?
Can anyone give me some more info an a P0115 error, other than it's Engine Coolant Temperature Circuit Malfunction which I know already.
Is it likely to be the temperature sender on the thermostat causing my fan error? I'm planning on doing some more fault finding on the fan by disconnecting this sensor to see if the fan runs constantly but I haven't got round to it yet. Also read some stuff about a low speed resistor in the fan failing but the fan doesn't seem to run at all so don't think it's this.
Sorry for the long post and I hope some can help!