Thermostat on cold startup

A

Andy's first frenchie

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Fellow Frogger
Tadpole
Tadpole
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I read somewhere (can't find it again) that Peugeot thermostats remain closed whilst idling when the engine is cold (eg. First start of the day in the morning) a lot longer than most other cars.
Firstly is this true? I always warm the car up every morning and every time it's parked for over a couple hours, and in the morning I've noticed even after 5mins the temp gauge hasn't moved.

Secondly, when does it start to open?
 
From the factory EP engine blurb:
"Sa température d’ouverture mécanique est de 105 °C.
Dans certaines conditions, le CMM pilote le thermostat afin de provoquer l’ouverture de celui-ci à 89°c."

The CMM is the engine computer. Temperature is determined by the resistance of the sensor probe at 5V. .The circulation pump. driven by friction, is not engaged at dead cold.
 
Merci Monsieur seasink.

This is a good excuse to learn French :)
It says it mechanically opens at 105 and electronically opened at 89. The latter is spot on because its never gone past the 90 mark even though it tickles it sitting in traffic.

I'm a little concerned about the mechanical opening temperature though.
 
just so this information can be useful to somebody else .such as myself, can you let us now which mode Peugeot it is applicable to ,in pretty sure not my 404 ! maybe my wife's 307 ,but in sure its pump is driven by the cam belt
 
Andy the 'concern' about the mechanical opening is the best failsafe you can get. This is the Old Thermo-syphon principal with a mechanical assist. It gets to 105C and the trap door is opened, much more efficient than draining the stationary battery running the electric fan alone.
:drink:
Brendan.
 
I'm just not trusting modern electronics so I'm old skool in wanting a mechanical thermostat that opens around 95degC. I've only had the car for several months so haven't experienced proper hot days and adverse driving conditions.
 
My car with the same engine has never overheated, not even on a 45 degree day a while ago. Mind, the fan was flat out.
 
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