Rough idle anyone experienced this intermintent

[Caldean]

Hi everybody i have an mini cooper s 2004 which has a rough idle sometimes has anybody ever experienced this on this model and any fixes it doesnt cut out but feels like it could give a blip of the trottle it disapears its quite strange no codes get thrown up or lights when it happens any ideas i know its due an inspection 2 in the next 5000 miles am thinking along the lines of plugs any other ideas

[jdl_1967]

Corroded coil pack connection/s?
Failing spark plug lead?
Worn / faulty spark plug?
Dirty or faulty MAP sensor?
Dirty throttle body?


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[jonnie]

Hi everybody i have an mini cooper s 2004 which has a rough idle sometimes has anybody ever experienced this on this model and any fixes it doesnt cut out but feels like it could give a blip of the trottle it disapears its quite strange no codes get thrown up or lights when it happens any ideas i know its due an inspection 2 in the next 5000 miles am thinking along the lines of plugs any other ideas

My car, also r53, does this as well.It has new plugs and leads so maybe something else on the above list? It has never cut out either, and doesnt always occur.

[Sideways Steve]

Mine done this when the supercharger recirc valve was not fully closing. Its worth checking thats closing fully and at the same time cleaning the throttle body.

[Caldean]

Cheers steve how do you check it

[jdl_1967]

http://img.tapatalk.com/d/14/04/28/se9ymu3y.jpg

The bypass valve is located just below the right intercooler horn as marked in the above photo.

You will see a small screw in the photo, this is the stop to control where the valve rests. It should have thread lock or similar on it. When the car is not running or on tickover, you should be able to feel if the wee arm at the bottom of the screw is actually touching the screw, push lightly on the underside of the arm to see if it moves up at all. If it does move up, it's possible the spring is weak and the item needs replacing. If the arm is already touching the screw, it could still be out of alignment if the screw has moved at all. You cannot tell if this is the case without removing the valve as you need to see how the butterfly valve is sitting in relation to the arm position.

The bypass valve can be removed and replaced in about 45-60 minutes, albeit it's a bit of a skin removing operation on the knuckles / hand.

There are instructions on some Mini forums.

John


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[Caldean]

Thanks for this info john thats appriciated should be able to check this tomooriw with this info

[jdl_1967]

You're welcome.

Gently pushing on the black plastic arm towards the vacuum unit should give you an indication on the strength of the spring just by feeling the resistance and how quickly the arm returns, it should be instant.

I doubt the rest position will have gone out unless a previous owner has adjusted the stop screw. I wouldn't attempt to adjust this to be honest, I think you need some sort of feeler gauge inside the butterfly valve to measure the correct position. Someone here might know.


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[jonnie]

Thanks for that.

[Mon the fish]

Give the MAP sensor a clean as well

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