Hi, I have just bypassed my Heater matrix on my Pug 306 XND 94
The two latge cooling fans will not come on, ewven though my temperature dial gets up to just below 100C before I have to turn off the engine to cool it.
Any Ideas, I was thinking an air pocket or someting? They did work before I bypassed the heater matrix by joining In/Out pipes together.
Any Help Greatly Appreciated!
Mnay Thanks..
Hi,
Does the raidiator get hot? If not, it could be a bust thermostat that is not allowing water to flow through it. Replace the thermostat.
If the raidiator does get hot then it must be a problem with the electronic system; Temperature switch, Wiring etc.
I don't believe it would be a air pocket restricting coolant flow, if it was the engine would rise in temperature very quickly (
Years ago I bypassed the heater on an old Vauxhall Chevette and the same thing happened. It was because the coolant was not being cooled by going through the matrix. The answer was to connect the two hoses with a solid bar, instead of a piece of pipe, giving the same effect as when the heater is turned off and forcing the coolant to circulate via the radiator.
On the 306, water constantly circulates through the heater matrix (there is no value in the 306 heater matrix). So adding a solid bar would completely block coolant flow.
You need to check whether your electric cooling fans are working. If on tick over they don't cut in and the engine overheats, then either the fans or the sensor is faulty. You can check the fans by bypassing the sensor to see if they operate. Make sure you don't have any loose clothing etc near by.
If the fans work then the problem is with the sensor. On a 406 they are only about £5 each and fairly easy to replace. Not sure about the 306 though. Hope this helps.
Have you got aircon on this model? If so the fans should come on in series (slow mode) as soon as the aircon is switched on irrespective of the engine temp. If they don't work under this test ,suspect fuses, wiring and the three relays used for switching between off,series and parallel. If they work for the aircon then it could still be the above but also could be the sensor. Not familar with the diesel but it could well be near the water circulation thermostat housing.
Bob
Well put - just to add and it would probably cause more trouble than its worth.
which two large cooling fans are we talking about here? I have 306. The fan on the switch on the fan needs checking first.
Bill
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