Renault Scenic

**Crilly** · 31st May 2005

First of all, I now shit about cars, so i may sould like a complete idiot.

I have a T reg Renault Scenic auto, which keeps stalling when i come to a stop at lights and junctions, it does not do it all the time but 5/6 time on a journey on Sunday i think is enough to be concerned.

I only thing that i think may be causing the problem is that the car tick over is far to low, it currently idles at about 600rpm where i think it sould be about 1100rpm.

Can anyone tell me what the ideal idle speed should be and whether it is easy to adjust.

Cheers

**-NEO-** · 31st May 2005

The best to my knowlege, these types of things are not easy to adjust! Most new cars like that are all electronically controlled by small computer on your engine. This computer controls alot like monitors temperatures, speed, fuel etc..

Funny thing is, my sister had a renault clio! it was quite a new model and it was doing the same as yours! She tuck it to the garage, and because it was hard for her to show the mechanics how it kept on stalling, the mechanics could not find a fault!

So she went how with it, and it started doing the same again!

Anyway, in the end, it turned out there was a fault spark plug! After a �10 plug, it was working fine!

My advice is, i would take it to a renault dealer and have it checked up! Most new renaults, like alot of cars now have a system built in that tells the dealer if there is any problem with the car. But the only way to do this is by talking your car to the dealer, as you need a special computer to read the cars onboard chip!

Anyway, hope this helps!

**Big Red** · 31st May 2005

Bit more info required on engine size, year, 8valve or 16 valve.
The petrol renaults are prone for faulty ignition coils on the 16 valve models.
These are coil on plugs(one on top of each plug)
Is the car running ok, or is it down on power.
If one of the coils is faulty, it will possibly only be idling on 3 cylinders and this will give low idle speed.

Idle is not adjustable on modern cars, as already mentioned it is controlled by ECU.
It will use either a stepper motor at throttle linkage to control idle or an idle speed control valve.
This is just a solenoid that opens and closes an air channel very quickly to give you a set speed.
These get gummed and carboned up and often need cleaning out.

I have also had problems with coolant temperature switches on renaults.
This tells the ECU the engine temp and it then adjusts the mixture, timing and slow idle speed.
If the temp switch is saying the engine is cold when it is at opperating temp, the ecu is sending a signal to the injectors to increase the pulse width and deliver more fuel as for a cold engine.
This will bog the engine down and make it cut out.
So many possibilities, you really need to get a local garage to check for stored fault codes in the ecu, and also to have a look at the live data going in and out of the ecu.
Local indy with decent diagnostic kit will be a lot cheaper than the stealers.

If you need any more help, give me a shout.

Gordon