I posted before about a over heating problem.
I want to check that my temp sensor is working, but im not a expert on cars.

How do i firstly locate the sensor and check that it is working?

Anything else i can check to see why my cars overheating?

Ideas? Need help to locate parts to (Useless)

Mark 1 Punto, 8 Valve, 1.2, 1998

Whats most likely to fix the overheating? Temperature Transmitter switch? Radiator fan switch? or coolant temperature switch?

For parts, Big Mick at eurocarcare in Derby. (Google will find.)

First check that there's a thermostat in there and that it opens -- pan of water brought to boil on stove. It's not unheard of for morons to remove the thermostat to try and mask overheating -- this will tend to cause overfuelling until the overheating sets in.

Check coolant levels and bleed the system. Look carefully (including under the car) for leaks when up to normal temperature (engine running).

You can test the blue temp sensor in the same way with a multimeter connected. Should show steadily increasing resistance from cold.

You can check the radiator temp switch in the same way, but it should simply switch at a given temperature.

Compression test recommended -- post the results.

Hi folks!

I've changed the thermostat in my 75 SX due to, what I thought, was low running temperature. The heater fan is blowing nice and warm and the radiator fan kicks in when standing still. But the temp gauge is reading very low, only about 1/4 on the scale. I've measured the gauge temp sensor (red one, in back of the head) to 205ohm when the radiator fan kicks in. Does anyone know what the resistance should be when temp gauge is at 90 degC (midway on the gauge scale). I've looked in the Haynes manual that I got on pdf's but I can't find any tables with sensor resistance according to temperature.

Any help wold be highly appreciated.

Best Regards

Hmm I don't have the specs on me or a Haynes manual, but will try and locate the Fiat pdf for it I have.

At worst you could try a new temp sender, about £10 new online.

dunno if the 75 uses same temp sender as the 55 and 60, but on them your looking for
10kΩ @ 0°C
5kΩ @ 20°C
10Ω @ 60°C

But in the haynes, your looking for the first page of the Chapter titled 'Fuel, exhaust & emission control systems' for this info.

Thanx a lot folks! Used the IAW Scan software yesterday and my injection temperature sensor was reading 90degC when the fan kicked in. So I definitely need a new sensor for the temperature gauge. Fiat parts at norwegian Fiat shops is hopeless, have to find it online.

Thanx again.

If norway has an ebay, try that.

failing that

www.shop4parts.co.uk

have them and may ship internationally.

rpmhead said:

Thanx a lot folks! Used the IAW Scan software yesterday and my injection temperature sensor was reading 90degC when the fan kicked in. So I definitely need a new sensor for the temperature gauge. Fiat parts at norwegian Fiat shops is hopeless, have to find it online.

Thanx again.

Click to expand...

Hang on, 90C seems about right for the fan to come on. If the fan is working at all, it's unlikely to be the cause of overheating.

i think you may have mis-read that fingers, as i understand he's saying the fan comes on at the right temperature but the gauge shows a different temperature and thus the sensor for the gauge is whats wrong and the car isn't actually overheating... unless i read it wrong lol.

Maybe. Worries me that they seem to be looking for overheating in the guages, rather thajn elsewhere..........

well kinda confirms the gauge is wrong, need that to work in order to be sure its not overheating but i'm guessing IAW Scan would tell you if the car was overheating? I never used any of the scanning software myself so not sure what they can and can't tell you..

IAW scan will only record the temperature signal from the CTS, therefore the OP is stating that the engine management side of things is working well.

It is most probably a faulty gauge sender.

blu73 said:

i think you may have mis-read that fingers, as i understand he's saying the fan comes on at the right temperature but the gauge shows a different temperature and thus the sensor for the gauge is whats wrong and the car isn't actually overheating... unless i read it wrong lol.

Click to expand...

That's correctly observed! I have no overheating problems, only low indication on the temp gauge in the car.

this is the farthest my temp gauge has come so far since i have put a new dashboard and temp sensor in my 1.1 55s mk1

second pic shows temperature sensor location

Gets as confusing as hell when you just hijack other people's threads :bang:

Check thermostat.