Clio 1.8 16v, High idle issue

[RenClio16V]

Alright so my clio is finnally on the road. Ive been under the car more times than i can count over the past weeks, managed to problem solve along the way but theres a problem with the idling

Once ive gone over 4000rpm ( roughly )
The rpm will only drop to 1500 not to the 1000 its supposed to, any ideas?.

Ive changed

lambda sensor
Map sensor.
Cleaned icv

Im really unsure as it wont drop back down to 1000, unless the engine is turned off and started again, as if it resets itself ive no idea.

Theres also a post on a different forum which sounds like the same issue but there was no fix:
https://www.honestjohn.co.uk/forum/post/index.htm?t=56018

 

[White16valver]

Could there be an air leak in the intake system between the air box and the intake manifold?

I'm pleased to hear a valver is being saved!

 

[RenClio16V]

Could there be an air leak in the intake system between the air box and the intake manifold?

I'm pleased to hear a valver is being saved!

I have had my head under the bonnet for ao long lol, nothing obvious that points out an air leak, im thinking throttle cable now but still unsure.. could my problem be a sticky tb?

 

[Coops Mk1]

its the road speed sensor, common fault. its part of the speed cable and the earth on it can break or become poor

you need to either change the cable for a good working one or re-earth the black wire on the three pin plug on the top of the speedo cable behind the dash clocks

basically what is supposed to happen is when the speedo sees car moving it will keep the revs up at 1500 for smoother gear changes etc so you're never at idle, then when you stop the idle returns to 1000, but when that sensor is faulty you get the exact issue you are describing here

 

[RenClio16V]

its the road speed sensor, common fault. its part of the speed cable and the earth on it can break or become poor

you need to either change the cable for a good working one or re-earth the black wire on the three pin plug on the top of the speedo cable behind the dash clocks

basically what is supposed to happen is when the speedo sees car moving it will keep the revs up at 1500 for smoother gear changes etc so you're never at idle, then when you stop the idle returns to 1000, but when that sensor is faulty you get the exact issue you are describing here

Thanks coops for the info !
Ill be stripping the dash out this weekend and have a look what is really happening behind it.

Also, the temperature on clocks and heater stopped working at the same time, any ideas? Ive checked all fuses seem fine,

Cheers ! ?

 

[White16valver]

Thanks coops for the info !
Ill be stripping the dash out this weekend and have a look what is really happening behind it.

Also, the temperature on clocks and heater stopped working at the same time, any ideas? Ive checked all fuses seem fine,

Cheers ! ?

I know resistors can fail in the later model Renaults, meaning you have all-or-nothing heaters/fans, but I don't know if it happens on the Mk1 Clios!

 

[RenClio16V]

I know resistors can fail in the later model Renaults, meaning you have all-or-nothing heaters/fans, but I don't know if it happens on the Mk1 Clios!

It was working great on a drive out, then suddenly stopped working completely. Lol, but first things first the dash out still ? thanks White16valver ?

 

[White16valver]

Good luck, I hope it can all be fixed easily!

 

[RenClio16V]

Ill keep you two updated on this lol

 

[Wobba]

As said, air leak or speedo cable issue. The earth is quite easy to sort after you get the top part of the dash off and clocks out. I did it with my Williams years ago.

Do check for air leaks though first. Get it idling again at 1500 and pop the ISCV feed off the airbox and block it with the palm of your hand and it SHOULD stall. If not you may be able to hear where air is getting sucked in. Don't let any loose items get sucked in the pipe...

The sensor on the top of the thermo housing (brown iirc) is the sensor for the temp display. Most are old and brittle now where the plug wiring is.

The fans can be the resistor under the skuttle. All easy to sort

 

[RenClio16V]

As said, air leak or speedo cable issue. The earth is quite easy to sort after you get the top part of the dash off and clocks out. I did it with my Williams years ago.

Do check for air leaks though first. Get it idling again at 1500 and pop the ISCV feed off the airbox and block it with the palm of your hand and it SHOULD stall. If not you may be able to hear where air is getting sucked in. Don't let any loose items get sucked in the pipe...

The sensor on the top of the thermo housing (brown iirc) is the sensor for the temp display. Most are old and brittle now where the plug wiring is.

The fans can be the resistor under the skuttle. All easy to sort

Hi wobba, thank you so much for the detailed info, saved me from dragging out the whole dash lol !

Will try all the above as you mentioned and then report back ! Thanks guys, id not have been able to troubleshoot these problems without you guys !

 

[Wobba]

The clocks are easy BUT it can be fiddly because the part that goes into the speedo clocks needs to be pressed quite hard to release it. I find small children are good for this part.. While you are back behind the dials, you can replace those pesky little bulbs that have blown too

The MK1's are easy to work on once you are used to them and stuff like this becomes easy to diagnose, you'll be a pro in a year

 

[RenClio16V]

The clocks are easy BUT it can be fiddly because the part that goes into the speedo clocks needs to be pressed quite hard to release it. I find small children are good for this part.. While you are back behind the dials, you can replace those pesky little bulbs that have blown too

The MK1's are easy to work on once you are used to them and stuff like this becomes easy to diagnose, you'll be a pro in a year

Its my first real project car, ive learned so.much already but its like its never ending once one thing is fixed another thing goes ! ?‍♂️

 

[RenClio16V]

Wire looked in alright condition behind the clocks, but re earthed it anyways just in case.

Didnt do the fix sadly. Ill have to inspect for this air leak then if there is one ?‍♂️

 

[Coops Mk1]

if not that then its the sensor on the cable itself and that will be a pain as don't think new cables are available anymore

 

[RenClio16V]

if not that then its the sensor on the cable itself and that will be a pain as don't think new cables are available anymore

Oh my god, so i have to stick with this idle issue ? ? the speedo needle also judders anything to do with it?

 

[Coops Mk1]

That's a worn cable or worn shim/insert on the speedo output drive in the box