ENgine Temperature

[jemo]

Im driving a megane 1.6 vvt manual car and it has clock about 65000 km. I am experiencing engine temperature dropping issues when the car decelerates. You can actually see the temperature gauge dropping one bar when it is decelerating. I have sent the car back to my dealer and they have changed the sensor, thermostat and the temperature gauge itself but the problem is still there. According to them, they had plugged in to CLIPS and diagnose the issue and they noticed that the drop is only 2 centigrade. Thus they are puzzled as to why the temperature gauge drop down by one bar. Anyone have any idea on what is happening?

[davelowe]

The gauge or more probably the wiring is at fault - particularly if the CLIP is getting correct temperature readings from the ECU.

[jemo]

oh i forgot to mention that when im cruising, the temperature remains normal. so does that still mean that the wiring is at fault?

[steve-t]

I had a similar problem on a rover few years back
air lock in the coolant system caused by leaking radiator
Just an idea
Steve

[davelowe]

I had a similar problem on a rover few years back
air lock in the coolant system caused by leaking radiator
Just an idea
Steve

Good point! It wouldn't surprise me if the dealer didn't spot something like that.

Check and report back the coolant level and see if it losing any. DO NOT put radweld in. A good look around under the bonnet (and behind the heater) with the under tray removed should show traces of white corrosion if there is a leak (obviously if you have to keep topping it up, it's losing it from somewhere - hopefully not internally).

What state is the water pump in? Any white smoke?

[jemo]

no white smoke car is performing as it is. Coolant level is still the same. Level didn't drop.

[nathan black]

sounds like a glitch in the map. you need to get the ECU reprogrammed. its not as expensive as you think.

[jemo]

the car is under warranty so i'll just tell my dealer about the above suggestions. Hopefully it will be cured

[davelowe]

Please let us know how you get on.

[jemo]

sure..just that its been in the dealer for 2 weeks already for gearbox issue. so i guess it will take a while for the temperature issue to be solved

[jemo]

okay just got back my car. and the problem is due to a faulty thermostat. it seems like the new thermostat is faulty too so it gave the same problem. the second new one is working normally so its fine now.