Hello to everyone reading this, hope you are all well.

The cooling fan on my 2003 1.8 petrol elegance comes on when I turn the ignition key. (Slow first click, fast on engine start, stops when I turn off ignition) also the temperature guage on the dash doesn't move.

I've read through a number of posts here on similar issues and so I think i've narrowed it down to three parts (I've checked fuses 35,39,40 and 50).

The coolant temp sensor
The cooling fan switch (Don't know where that is yet)
The thermostat (Is that a relatively simple job?)


Do you think this is the right road to go down? , as none of the parts are expensive i don't mind doing all three.

Cheers.

Hi....welcome to the Forum

I would start with the coolant temperature sensor which is normally located on the top of the engine near to the thermostat housing area and within the cylinder head.
Firstly I would check the plug going to it isn't broken or corroded.

The cooling fan switch should only run the cooling fan and not provide any feedback to the gauge.

The thermostat shouldn't be an issue regarding the fan starting up from cold and also the gauge but its worth checking that all coolant hoses are similar temperature when running.

Let us know what you find

Hi,

 

Thanks for the feedback.

 

I tried the pedal error code routine and got 0136,0140,0170 and 0115.

 

0115 Refers to the cts, so that's where i'll start. I've got one on order, due Saturday, so ill fit it and let you know.

 

As an aside how many lamda sensors do I have? There's one near the manifold and one near the flexi joint further down. Are they both 02 sensors?

 

Thanks again

Just thought, now you mention it, yeh, the thermostat only allows water to flow at a certain temp doesn't it?

 

Cheers

There would be two lambdas, one for upstream and other downstream of the cat.
The upstream one calculates the fuel mix and the downstream one reads the efficiency through the cat and feeds back accordingly

Hopefully the replacement CTS will do the job

Hi,

 

Just to let everyone with a similar issue know, I changed the coolant temperature sensor and it solved the problem. The temperature guage now works and the fan doen't come on at start up.

Dead easy job, only took fifteen minutes, and the part was about £5 from e-bay.

 

With ref to the Lamdas and the error codes, they're a bit pricey so just wondering, on a hunch, which one would you change, or both, also would it make a lot of difference. Recently passed MOT with fault codes, so no probs there.

 

Thanks,

John.

Glad to hear your positive result and cheap part as well !

I would give the engine a good blast and see if that clears the lambda faults, sometimes thats all they need