Saxo 1.1 Idle Problem.

8th January 2016, 17:05

Hi guy's. Sorry if this is a repeated question.
My 1.1 51 plate saxo is idle'ing rough. It sometimes drops from the original 750rpm or increases.
I understand it is either the Idle Control Valve or the Coolant Temperature Sensor so I went ahead to change the Coolant Temperature Sensor but this did not solve the problem, however.. My fan has now turned on. Why? I have checked the coolant level and it is fine.

I will go ahead and change the idle control valve once I have sorted out this fan issue.

Thank you.

9th January 2016, 08:08

Update.

I have replaced the sensor back to the original and the fan has now gone off. Could it be a faulty sensor I installed? Even though it was new?

21st January 2016, 23:42

Hi,

The engine idle RPM is most likely the idle stepper motor, this is mounted on the front of the throttle body in the engine bay. Not sure if I'm allowed to link to another site but if you search for 'bosch idle stepper' on Google you will find an article with some photos on MIGWeb that show how the copper strips tarnish over time as a result of age.

This results in the idle stepper not being able to check the position of the idle stop hence the 'hunting' at idle RPMs. I would advise replacing the part as they are only around £20 on eBay (just ensure the part no. is '0 132 008 603' which should be the same as what is on the old one in your car).

As far as your radiator fan is concerned, it could be one of three sensors, two mounted on the gearbox side of the engine, one of which is for reporting coolant temperature, other is for lighting the coolant overheat light on your instrument cluster. The remaining sensor is screwed into the right hand side of the radiator (as you look at the car) but this shouldn't really go bad as it only instructs the fan to switch on when a pre-set temperature is reached (98c or something for the fan I think, not sure).

My bet is one of the two coolant related sensors on the side of the engine but you would be well advised to take a look through one of the other threads on the forum with more details, also try procuring a replacement one of each from a scrappy to try changing over (be aware they may also be faulty though).

Hope this helps,

Hiro