Rough idle when hot and cold

[Nads54]

Hi all recently bought a clio 172 and when starting from cold it idles very rough like it's got cams and if you try to rev it acts like it's got a misfire once warmed up a bit it's fine but also on hot idle it's still very rough and temperature gauge sits a notch above the middle

Anyone have an idea what it could be?

Cheers

 

[Smartie93]

The idle is quite rough anyway. Especially if you're used to refined modern machines. They're all a bit rubbish for the first 2 minutes of running. I imagine it's a result of the calibration for cold start emissions.

My temp gauge sits slightly above the middle on a hot day in traffic and just below when coasting downhill. I believe they are meant to be rock solid in the middle, oem temp gauges don't typically give the true temp reading anyway! But it's never bothered me in the 5 years I've owned it.

 

[497adam]

Who did the belts last ?


Sent from my iPhone using Tapatalk

 

[Nads54]

Who did the belts last ?


Sent from my iPhone using Tapatalk

Has a receipt from a garage that it was done in 2018

 

[Nads54]

The idle is quite rough anyway. Especially if you're used to refined modern machines. They're all a bit rubbish for the first 2 minutes of running. I imagine it's a result of the calibration for cold start emissions.

My temp gauge sits slightly above the middle on a hot day in traffic and just below when coasting downhill. I believe they are meant to be rock solid in the middle, oem temp gauges don't typically give the true temp reading anyway! But it's never bothered me in the 5 years I've owned it.

could it be the coolant temp sensor / thermostat needs changing?

 

[Smartie93]

could it be the coolant temp sensor / thermostat needs changing?

Causing the temp gauge to read strangely? Maybe.

But I would post a video of your rough idle if you can, it could be a case of "they all do that sir".

 

[Nads54]

Causing the temp gauge to read strangely? Maybe.

But I would post a video of your rough idle if you can, it could be a case of "they all do that sir".

Okay il get a video when I'm back from work

 

[Krarl]

If it's really rough and nearly stalling then a new CTS or IATS might be needed

My old 172 would stall from cold because the CTS was being a massive prick

 

[Nads54]

For some reason it's not letting me uploading a video but I took the car out today and it was running okay went to fill up petrol and put in tesco 99 and car feels noticeably smoother also I have eml light on and service light so I plugged in my bluetooth obd2 reader on torque app and it came up with P0325 and P0420.
The P0420 is probably due to decat but the p0325 is knock sensor could it be because I was using 95 ron before.

also the app shows the coolant temp and it was running at 97 degrees on idle hot is this normal?

Also noticed my temperature gauge sits above the first notch when stone cold is that normal for these cars (pic attached)

 

[Cookson]

95 ron 😬😬