Supposedly overheating of engine often happens in Peugeot, but it is an engine coolant (antifreeze) temperature sensor that gets out of the order.
Firstly, as a rule, the temperature pointer starts slacking (as it is shown in the video below), then, when the sensor is completely out of order, the pointer drifts into the red zone of engine overheating.
There are several kinds of thermostat housing, in which a sensor is fixed with an installed external and internal alternate.
Usually, there are no problems with an external alternate; its replacement does not present any difficulty or trouble, it is shown on a photo.
Lift the plastic electrical wire bundle up – 6
Pull the catch out – 7
Cut the electrical connector off
Take a temperature sensor out – A
Replace a rubber sealing ring.
Let us speak about how to get rid of the problem of engine overheating by changing an installed temperature sensor. Of course, an installed sensor cannot be replaced without changing thermostat housing itself, but there is a much simpler way out. The French are crafty and they invented a sensor-insertion, which is driven in a drain valve of excessive air in a cooling system. It is presented on the photo.
But firstly, one needs to get to it, in order to replace it replace it with a bleeder plug. Doing this in standard models is much simpler than in turbo ones.
If your Peugeot is standard, not turbo, you can do this having turned off a resonator and an air intake manifold.
Caution: do not change it without releasing pressure from the water cooling system by removing a cap from the expansion tank, otherwise you risk to be poured over with hot antifreeze from the turned off drain valve.
Remove the cap from the expansion tank, wait for a couple of seconds, and tight it back. Now you can install it. Do not worry, antifreeze will not pour out from the removed drain valve (well, 5 grams do not count, it is no biggie). After this you will not have to run fluid through the cooling system.
In turbo models it is a bit more difficult to change it; you will have to take two air intake manifolds, without this you cannot get to it.
Do not forget to turn an electrical connector on, you will find it a bit further in the deep. After installation you do not need to run anything through