Fan switch

[stu_19820]

When stationary in traffic my engine temperature rises, the fan doesn't kick in until the temperature gauge is in the red. Is there a way of adjusting the fan switch so that the fan comes on earlier? Or do I require a new fan switch?

[Catso]

'Red' is open to interpretation, do you know how hot it is in degrees? I presume not. Manufacturers can make the gauge go into the 'red' at any temperature, it doesn't mean anything in itself.

I wouldn't worry about it, if you engine doesn't boil up, then everything seems to be doing what it should. Engines can get to well over 100 degrees centigrade without boiling.

[smptrds]

Personally, I would ignore that reply from Catso as too high a temperature over a period of time can cause damage to gaskets and even warp the cylinder head.
My first expence would be to replace the water temperature control gauge which may be screwed into your radiator or near by. Halfords or your service garage could advise you. These items are reasonably cheap and control your fan to cut in at a certain temperature.
It sounds if you may have an older car and these items do fault.
Good Luck.

[madman06]

is your car a rover by any chance as the thermostats on them are crap , wire a switch from the battery to the cooling fan,and have the switch in a spare place in car remeber to put an in line fuse in though

[mrjamie21]

Is your car a Punto? Mine was doing exactly the same thing, when I was stationary the temp would rise until it was in the red. Then would go back down when I started driving again. I didn't think much of it until I was in a traffic jam and smoke was coming from the bonnet. I took it to the garage the next day and turns out the fuse had gone in the fan.

[Catso]

Yes, smptrds, you're right, but the points I was making were:

In my experience, senders and gauges go/show wrong far more often than the simple thermostatic switch. If the fan NEVER came on, then fair enough, it's faulty, but this fan IS coming on and apparently when the engine heats up, as it should, so it would appear to be working.

Manufacturers are often err on the side of caution and often 'in the red' can be only a few degrees above the coolants thermostat's setting. Actually, the hotter the coolant, the faster it will lose heat throught the radiator. So the system is sort of self-regulating, even without a fan.

So, without any supporting evidence that the engine really WAS too hot, I wouldn't believe the gauge.

[homer75]

I agree with Catso - as long as the fan is cutting in then no worries. As for Halfords giving advice - I have yet to meet an assistant there who knows what planet he or she is on never mind give opinions on engine temperatures. Also - for God's sake don't start rigging up extra switches to the fan. During normal driving the air flow through the engine works with the cooling system to regulate the temperature. The fan will only cut in occasionally when the vehicle is stationary for a length of time and more so in very hot weather. Relax in the knowledge that the sensor/switch and cooling fan are working.

[Toureman]

I agree with CATSO, if your car coolant never boils leave it alone, temprature gauges are not that reliable!

Don't bother with Halfords!