[fatsweaty]

Ok, had this problem for a while when warm the 2002 Scenic idle runs low around 500 rpm and moves up and down a 100rpm or so, otherwise runs fine whilst driving.

I have cleaned ICV , MAP and TDC sensors made no difference.

All coils replaced after one went.

Today i changed plugs for Renault ones with correct gap still no change.

Old plugs were a brown colour on the tips (if that helps). Car passed its emissions fine a few months ago whilst this problem has existed for 18 months or so.

On a secondary point the battery we have in there i think is not correct one, was supplied by a motor factors as a replacement for one they also supplied that was faulty....would that have any effect on this problem.

Any info would be very much appreciated on this.

 

[madnoel10]

Has the engine coolant temp., sensor been checked?

 

[fatsweaty]

Madnoel....no didn't think that would effect the engine idling low, i would have thought it would idle high, obviously i could be wrong though lol.

How do i go about checking it, what am i looking for?

 

[madnoel10]

If the coolant sensor is faulty the ECU may think the engine is cold when it's actaully hot or vice versa.

First check it connections are clean and sound as a dirty connection can cause high resistance.

If all is OK in that respect check its resistance when cold and then again when hot. When hot there should be a massive drop in resistance.

 

[bobbydog]

I've had this problem, erratic tickover for some considerable time.
Don't get throwing money at it like me.
Everything that can be replaced has been, sensors etc and it still has this niggling little problem.
Saying that that though the engine runs as it should above tickover.
I just live with it now.

 

[bobbydog]

Oh i almost forgot,
After extensive exhaustive research on this problem renault reckon its ''normal'' for the K4J, K4M engines to have slightly undulating tickover as they are designed for high speed performance or something similar!

:rofl::rofl:

 

[fatsweaty]

LOL ^^

Its such an annoying issue, i really don't want to put it in for a diagnosis to be told they can't find anything. The car runs fine just idles low/erratic. The old plugs apparently are in normal condition being a tan/brown colour so no "real" engine issues like overfuelling etc.

The mpg is around 33 mpg in normal driving, is that normal figures, i don't know.

I can't check the coolant temp as i don';t have a multi meter to hand, i think i found it, has 2 green 1 pink wire near thermostat.

Cheesed off.

 

[bobbydog]

I was told it was caused by not having ''proper'' renault spark plugs fitted, i bought some it made no difference!
After replacing the throttle body & inlet manifold i gave up.
Some time ago another member suggested the only last thing it could be was a weak valve spring, no comment.......

 

[mickeybo]

When cleaning throttle bodies it's imperative that you insure the passage airways are clear. Idle speed
for these is all models 750 rpm. The idle air control
valve has a 4 terminal plug marked a-b-c-d disconnect this plug at key on must have 12v's at
terminal a Terminal b key on 0.3v's Terminal c key on
0.27v's Terminal d at ign on 12v's. The throttle
position sensor has a 3 terminal plug marked a-b-c
remove plug for checking. Terminal a (ground) terminal b at key on 5v's Terminal c ign on 0.5 v's
throttle closed. Throttle fully open 4.5v's Hth
Regards Mickeybo

 

[bobbydog]

Thanks Mickeybo, some good info' there.

To the original threadstarter {dare i call you by your username Lol!} Injector problems can also cause a erratic tickover.
In the event you get it sorted let me know ASAP please!

 

[Peatah]

ive got the same issue
did you fix it or get rid?
mines been like it for 2 years :-(

 

[fatsweaty]

Afraid not, it is a constant annoyance to me. However the car still returns 35mpg on my wifes running around in it so i have decided to live with it and just service it as it requires. I am not prepared to chuck anymore money at it unless something fails.

 

[dami3n]

Afraid not, it is a constant annoyance to me. However the car still returns 35mpg on my wifes running around in it so i have decided to live with it and just service it as it requires. I am not prepared to chuck anymore money at it unless something fails.

I know this is an old thread and some people might go stop necroing. But.. did you ever check the alternator? Having a poor connection can lead to drops heck even an under or over tightened belt can do the same. If the alternator is a bit iffy it will keep switching between battery and alternator. But if it keeps enough power you will never see the battery light come on, that only comes on when it drops below a certain voltage. Might have been worth checking for dirty joints my main connector was covered with oil seemed to do the trick for a few months. Then i just replaced it, they are pretty cheap, 2nd hand low mileage though. Other way is to get the car running and test the battery when it drops if the voltage is changing it could be that. Guessing you got rid of the car by now though maybe not?