Peugeot 406D high temperature

Do you know the temp rating of your thermostat? I know when I got my car (a Saab 900), the thermostat it came with was a 92C, so thats the temp when the stat opens to cycle the fluid through the engine and radiator, but an

I am assuming you are talking about a 406 Turbo Diesel. Car temperature gauges are notoriously bad at providing the correct temperature reading. You can only be sure of the gauge reading if you check the water with a second temperature gauge. The thermostat opens at 83 C. The fans are controlled from an electrical system Both fans operate in series at 96 C (slow) Both fans operate in parallel at 118 C (Fast) To check the fans do both work, with the engine switched on remove the brown plug on the thermostat housing. After a few seconds both fans should come on at high speed. If your engine cools rapidly after reaching 90+ I would not worry. Water in a radiator is pressurised to lower its boiling point. If you have a leak in the cooling system it will affect the cooling system efficiency and lower the boiling point of the coolant.

Mike

Thanks for your advice Mike, big help

Terb I have a 2.1 406 Tdi and I had the same problem going to Cornwall last year, the temp gauge rose and fell an awful lot during the journey and I was quite worried at the time, but I was fine all the way there and back. Have not been out yet this year but I expect it will be the same so I no longer worried about it. So long as the temp does go back down there was no problem.

Barno