engine fan

[PHILIP BUXTON]

The engine fan on my GTL has stopped working. Presume this could be fan itself or the temperature probe and or thermostat problem How do I check each of these items and if need be how do i replace them

 

[malcolm]

Welcome to the forum Philip,

The thermostat is easy to check - if the radiator and top hose stay cold for the first minute or so of running, then become hot then the thermostat is working. Otherwise is there any water in the top hose? If not you might want to bleed the cooling system.

Normally the problem is the thermal switch or the electrical connections. I don't recall if there is a fuse. The electrical connections are vulnerable to corrosion. It's worth cleaning them up. You can check the fan and the circuit by removing the wires from the thermal switch and touching them together. The fan should come on (so be careful where you put your fingers).

To test the thermal switch check the resistance across the switch when you expect the fan should be working. It should be open circuit when cold then closed circuit when hot. The switch unscrews from the radiator if it seems to be faulty.

There is some discussion about thermal switch testing on http://www.renault4.co.uk/forum/about30.html It's common for these to fail.

 

[PHILIP BUXTON]

thanks for quick reply and advice, presumably would have to drain radiator before unscrewing thermal switch?

 

[malcolm]

I tend to drain the radiator by unscrewing the switch. Two jobs in one.

 

[PHILIP BUXTON]

replace radiator coolant

have tested fan and it is the thermal switch which is faulty and I have managed to get one which is same thread but I think was fitted on renault 5 I thought I may consider replacing engine coolant while i am attending to switch . This may be simple job but how do I go about it and ensure no air in systemetc

 

[malcolm]

Replacing the engine coolant is fairly straightforward. Drain the old stuff out by undoing the bottom radiator hose.

When everything is back together start by refilling the expansion bottle and screw the top back on. Turn the heater switch inside the car to hot.

Then undo the cap on top of the radiator (it's tight - you'll need a big spanner - I use an adjustable spanner). Fill the radiator.

After that I tend to squeeze the radiator top hose to pump the air out. Then replace the cap on the radiator, remove the cap from the expansion bottle, and keep pumping away at the top hose until it feels like it's full of water and bubbles have stopped coming out.

Then undo the bleed plug (on the end of the little rubber pipe that sticks out of the bulkhead under the windscreen). Squeeze the top hose until bubble free water starts coming out. You might need to open the bleed, squeeze, close the bleed, release and repeat.

That's how I do it, but it's not necessarily the method recommended in the book.

 

[Steve Hennessey]

Fill the radiator, replace the cap, remove the plastic bottle and get a friend to hold it up high (or use string if alone). Top up the bottle, run the engine at fast tickover, unscrew the bulkhead bleed screw and watch for bubbles. Keep the plastic bottle topped up half way at all times. As soon as the bubbles disappear from the bleed screw, tighten it, switch off the engine, secure the plastic bottle and go for a run. Let the car cool down and top up the bottle to half way. Easy!.

Steve

 

[PHILIP BUXTON]

THANKS FOR ALL YOUR ADVICE .
HAVE SUCCESSFULLY MANAGED TO CHANGE FAULTY SWITH AND REFILL RADIATOR ETC THOUGH TRICKY GETTING BOTTOM HOSE BACK ON