Peugeot Repair Questions? Ask a Mechanic for Answers ASAP
Sounds like a faulty coolant temp sensor..this is a fairly common issue across the 308 range in which a bad sensor which is located on the themostat housing..normally a green body type..goes open circuit or fails..thus this automatically puts the main fan into high speed even at cold start..sort of a fail safe..So as above id say the best place to start at least is to replace the coolant temp sensor first and see if that helps...sometimes it can be picked on a diagnostic machine looking at the live data to see if engine coolant temp is reading or not...if there is no coolant temp sensor on the themostat housing then you will need to updated themostat housing a wiring loom...I do hope this helps
Normally the coolant temp sensor can cause this ..but the only other thing it maybe is the main cooling fan control unit located on the fan shroud.its sits at the top right centre..you'll see 2 plugs going to it..one large at the bottom and smaller one at the top
Ok..the sensors only held with clip on thermostat housing..ensure its the correct type and has the o ring seal with it..
You may loose a little coolant but if its changed quickly enough you'll only need to top up a little if required..