Engine Running Temperature Too Low?

[thornebt]

My 2011 1.6 156THP has been running a bit on the cool side of late. I initially thought this was due to a faulty coolant temp sensor which I've now replaced. However, it's still generally running at about 70C (one quarter on the temp gauge) on country lanes with no other traffic - which seems low. If left idling on the drive it creeps up to mid way point 90C and stays there. It also seems slow to warm up making me wonder if it's the thermostat sticking open.

Does anyone know of the easiest way to check the thermostat without removing it? Perhaps by feeling hoses as the car is warming up?

 

[Anonymous]

My two month old 156THP has been running at less than 50'C for over a month. If I pull up in traffic the temperature creeps up to 90'C but as soon as I set off, the temperature drops immediately back to below 50'C again.

I reported it to the garage I bought it from but due to a lack of loan cars and having no technicians working weekends (Really? In 2014?) they couldn't book it in for a check for 3 weeks. (Shocking. For a new car...) Two days before it was due to go in for the check it suddenly started working normally after two and a half weeks of cold air round my ankles.

Monday morning - icy cold, Monday evening - icy cold, Tuesday morning - normal. As quick and sudden as that. I'm hoping it was just a glitch or an airlock near to the engine thermostat or thermostat sensor.

If it plays up again I'm tempted to change the thermostat and/or sensor myself as I don't want to be seeming to 'bother' the garage which was the distinct impression they gave me.

 

[thornebt]

That's encouraging. Perhaps my car will fix itself like yours. The temp sensor is easy to change on my 2011 156THP but your car will be under guarantee so that is easier still - once Peugeot find time to get it in the workshop. The airlock idea is an interesting possibility. I'll have to do some research to see how I might bleed any air out of the system. In the meantime I'll monitor it for a month or three in the hope that the gauge will suddenly return to the normal halfway position.

 

[thornebt]

Does anyone know where the coolant system bleed screws are in the RCZ 156THP please? In other models I believe you generally find them at the highest point in the cooling system, by the thermostat and possibly at the top of the radiator. I can't find any on my engine!

The RCZ is still running cold and although it's probably a slim chance it's due to an airlock it's got to be the best thing to rule out first as it costs nothing! Changing the thermostat in the belief it is stuck can wait till later.