Peugeot 406 over revving on idle

Oop?s Think I found part of the problem. Engine was out of oil!!! :( Put some in & is running OK now. Must remember to check this more regularly. :oops

"Scorpius" wrote

I have the same engine in my 405. It is almost certainly the idle control valve sticking. I clean it every now & then when it plays up. One day I will stop being a tightarse and buy a new one. It is right on top of the engine righthand side near the coil pack. Two fat hoses and an electrical connector.

Bob

Except on the 406 it's called a stepper motor and is on the throttle housing fixed with two torx 20 screws. Remove and clean with brake cleaner and also spray some cleaner into where it fits. Dry as much as possible and replace. It may be worth initialising it to the ECU. Switch the ignition on for 10 seconds, then off for 10 seconds then on again for 10 seconds then start the engine. You may need to full throttle it to get it going to get rid of the excess brake cleaner. Then it should run ok. If it still idles up and down, try the initialising again but disconnect the battery for a couple of minutes beforehand.

This thread interested me because my 406, which has never been a problem in this area, has, from the start, had a habit of quietly reving a bit every 3-5 minutes or so when idling for long periods. You know -- stuck in traffic. I have a theory that it is something the engine management system does for some good reason.

Apart from that I will print out Nigel's post and tuck it away in case.