Hi all

I have a 2 month old JCW with the N18 engine.

After coming to a stop I noticed revs dropping a little sometimes. Nothing to write home about but as I took the car in today to get something fitted I mentioned it.

They have increased the idle slightly to compensate.

1. What should idle be when it's warmed up and stationary?

2. Would increasing the idle by 100rpm have other effects when driving? It feels less smooth and elastic but it's entirely possible I'm being paranoid.

Many thanks

S

 

I can't speak for the N18 engine but my JCW N14 idles when it's warm at about 500-700 rpms. I live in CO and sometimes there are additives in the gas for winter which my engine doesn't really care for so the revs will drop slightly on idle then adjust back to normal. They also fluctuate ever so slightly if I put fuel cleaner in as well. It's nothing to worry about my friend.

 

Thanks for sharing your experiences.

Is an idle of 800/850rpm too high?

If idle is a bit high does that affect the drive ability through the rev range?

 

Maybe somebody has a scangauge that can give you an accurate reading.

 

My MC idles right at 750 to 800, as close as the eye can tell. Most vehicles fall in this range give or take a bit.

 

I am seeing the same thing after about 40 seconds at start up. On a cold start I see around 1100 to 1200 then it slows down to 800.

 

Thanks everyone. I reckon I'm in the 800 rpm range but rang the dealer out of interest. They reckon they know what they changed from and too so they'll let me know more about what they found.

They think they re-set the ECU to do this, which would explain why it drives a bit differently.

 

I have a scanner. It tells me that my cooper idles at 726-780 RPM when warm.

One thing you will notice if you use a scanner... the tach needle is off so very slightly. If the needle is on the 1000 RPM or 2000 RPM, I guarantee that the actual RPM is around 900 or 1900.

I'm OCD about this, so after being bugged about this for the longest time, I finally took out my tach and reseated the needle to the exact mark.

 

Ha! This would bug me too.

I'm going to see what the dealer measured it at and update

Cheers


S

 

I see this same thing on winter gas up here in Ohio, and I've got an N18. Showed it to the dealer and they deemed it "normal". Now that summer gas is tarting to trickle in, it seem to have gone away.

--Matt