[Flashez]

Hello,

Problem :
I have idle issue for several months now with my MINI Cooper S F56 2.0 192 with automatic transmission.
When I put it in P ou N (sometimes in D but never in R), the idle gradually rises to 1500rpm then goes down to 500rpm and so on.
This only happens when the engine is warm. I don't have any check engine light. No weird behavior when the car is rolling.
I went to MINI who has never seen this problem before.

Hypothesis :
My thought is the pre-cat O2 sensor (upstream) is faulty causing the ECU to poorly regulates fuel.
I tried to check sensor values through OBD port but don't have enough knowledge about those sensors.

Spark plugs are new, I run only RON 98.

What do you think about it ?

 

[JustaCooperMan]

Might be a bit late to the thread, but hopefully it helps. Mine did the same thing, turns out it was the fuel tank vent valve. Replaced the part, now seems to be idling normally.

 

[Flashez]

Might be a bit late to the thread, but hopefully it helps. Mine did the same thing, turns out it was the fuel tank vent valve. Replaced the part, now seems to be idling normally.

In fact you’re not. Still facing the issue. How did you know it was this part who was faulty ? Do you have a F56 too ? And why it would happen only when the car is warm ?
Thanks!

 

[JustaCooperMan]

I took the car to the stealership to look at a couple of problems. The informed me that my rough idle was caused by the fuel tank vent valve/ sensor being faulty. Bought the part and replaced it myself, 5 min job.

I indeed have an F56.

Yeah I think it only happened when the car was warm.

 

[Flashez]

I took the car to the stealership to look at a couple of problems. The informed me that my rough idle was caused by the fuel tank vent valve/ sensor being faulty. Bought the part and replaced it myself, 5 min job.

I indeed have an F56.

Yeah I think it only happened when the car was warm.

Is it easy to replace ? What is the part’s price ? Any reference ?
Might give it a try.

 

[JustaCooperMan]

Yeah was pretty easy to replace. Took all of 5 minutes and did it in the parking lot of the dealership! 13907621174 was the part I needed for my 1.5 Cooper, might be different for other models. Price was around R1600, which is around $120us.

 

[Flashez]

Yeah was pretty easy to replace. Took all of 5 minutes and did it in the parking lot of the dealership! 13907621174 was the part I needed for my 1.5 Cooper, might be different for other models. Price was around R1600, which is around $120us.

Well might visit my local MINI and ask them if they think this is a possible case for my problem.
By the way, is yours an automatic or manual transmission ?

 

[JustaCooperMan]

I've got a manual

 

[Flashez]

I've got a manual

Also, did you have any error code or check engine light on when you had your rough idle ?

 

[JustaCooperMan]

I had no check engine light

 

[Flashez]

Quick update !

I finally decided to try the replacement of the fuel tank vent valve. In fact I have ordered it from aliexpress (same as OEM) but for $18 only ! Link: 16.79US $ 43% OFF|Car Fuel Tank Breather Vent Valve for BMW 13907621174 1390 7621 174|Vehicle Check Valve| - AliExpress
And in fact, it actually resolved my problem ! 🥰

 

[helicopter pat]

I have just replaced mine for the very same problem, biggest pain was getting the plug off.

 

[OTB]

Might be a bit late to the thread, but hopefully it helps. Mine did the same thing, turns out it was the fuel tank vent valve. Replaced the part, now seems to be idling normally.

Spot on…. Thank you…
A BMW tech was leading me down a different route with this issue, which would have been a big job, £1200+. Luckily, £65 plus VAT and 20mins of my time…

 

[OTB]

I have just replaced mine for the very same problem, biggest pain was getting the plug off.

100%

 

[Flashez]

Spot on…. Thank you…
A BMW tech was leading me down a different route with this issue, which would have been a big job, £1200+. Luckily, £65 plus VAT and 20mins of my time…

Same for me ! They told me it would 110€/hour for troubleshooting and that the failure could cost well over 1000€

 

[neilo]

I had a similar problem with my cooper, fitted the vent valve 13907621174 located under the engine cover, and the warm idle is stable where it should be. I've cleared all codes but the stop/start doesn't seem to be working. Anyone encountered this?

 

[JustaCooperMan]

i think i did a couple times. most times it was cold, but could also be due to a vaccumb leak