Hello Everyone,

I am having some problems with my 1.8 20V (AGN) Engine.

1) I believe that I have my thermostat stuck OPEN for a long time. Is there some way to check if it's open without replacing it ? (i.e where do I check to see the coolant flow).

2) Recently my temp. guage is always reading cold. From what I've read here it seems to be the green temp sensor (4 wires)... So I'm gonna replace that. I also have another sensor (2-wires) fitted on the radiator hose... Any idea what is this ???

Regards

If your thermostat is stuck open then you will notice your engine always seems to run cold (about 70 degrees instead of 90), although you'll be relying on the temp sensor working correctly to know this. You will also find the climate control / air con doesn't ever blow as hot as it should when you turn the heat up. The rad top hose will generally only feel warm when it should be very hot to the touch. You may also notice slightly better performance but reduced mpg because the engine is running cooler.

On the 1.8T the coolant temp sensor is located in a mount where the top rad hose goes into the right hand end of the engine (if looking at it from the front), it's hidden just underneath the top engine cover, and has 4 wires going in. I'm not sure what the other sensor is you referred to, there is one that goes into the side of the radiator that controls the fans?