IDLE SPEED TOO HIGH

[CLIO16V_BOY]

My 16v idles normally at 900rpm for about 15 mins then suddenly gets the urge to idle at 1800rpm, if you switch the engine off then start it straight back up it goes back to 900rpm for another 15 mins then goes back to 1800rpm. any ideas what could be causing this, nothing as been touch, added or altered.

 

[Nick Read]

Coolant temp sensor needed replacing when mine did that. It was basically choking when it was already warmed up and not choking when it was cold and needed it. All sorts of other things it could be, dirty idle speed control valve, dodgy speedo cable etc. Best bet is get a Renault diagnostic box on it to see what sensor has gone cos that it quite likely the cause. Its quite a common problem but every one has a different fix for it.

 

[BRUN]

as Nick says idle problems seem common on Renaults........

first thing i would do though is to clean the idle speed control valve, basically cos this is FREE !........if that doesnt work then id go for the coolant temp sensor, and then the accelerator cable

 

[night.icon]

mine did this recently and it was neither it turned out to be a throttle switch parts were around 135+vat +labour

 

[DAVE77]

Mine did this a couple of years ago, and the local Renault dealer told me it was the throttle potentiometer. But when I changed the dials in my car, everything went back to normal, and I havent had any problems yet.

So I recon that when I unplugged the thottle cable and plug, the problem cleared itself.

 

[N.D.Hill]

We have seen many Clios and 19s with this fault and will preety much guarantee its your sppedo cable . Or more precicely the road speed sensor at the top of the cable , explanation . When you are driving your car and change gear, to avoid stalling the engine, road speed info is sent to the ecu from the sensor at the top of the cable . The ecu then holds open the air by pass valve which intoduces enough air to the engine so that it will not stummble and pick up cleanly when you accelerate again. With a faulty sensor once you have reached approx 40mph you will find you have a high idle speed. Switching of the engine resets the idle speed control valve and you idle will be ok again. If you do not reach the road speed threshold idle will go back to normal. You will also find that you can rev the engine as much as you like without the car moving and the idle will always go back to normal. If you have these symptoms id go for the cable. Try as DAVE77 has first just in case its a bad connection.

 

[CLIO16V_BOY]

Thanks everyone i will take a look in the next couple of days at it.