Rough idle (cold start), yellow engine light

lovechips said:

Hello there,

I have a 2009 Mini Cooper S Auto, Petrol and on the 55000 miles. I bought the car very recently and the only problem when bought was the sunroof as it was not working properly (which is not a big deal!).

The next day, I noticed that the car has a very rough idle. It starts at approx. 2 minutes after I start the car and never goes off. Yellow engine light came off and I took it well respected and well known Mini specialist. Left my car to him and took 1 month and £1500 picked up the car and it is not even improved 1%. Due to Coronavirus, now I cannot reach him (and I am not sure should I reach him as he couldn't fix anything at all). Other than this, the car drives perfectly.

You can watch the rough idle video from here

And here is a list of what my mechanic did to the car

1 Investigate engine rough running & warning light on:

• 2745 DME: Multiplicative mixture adaptation
• 2786 DME: Additional mixture adaptation
• Carried out a mixture control text module
• Multiplicative mixture adaptation: partial load fuel-air mixture too lean
• Additive mixture adaptation: Idle fuel-air mixture is too rich
• Cylinder idle quality values outside of setpoint values
• Require to check intake system for air leaks
• Carried out smoke testing for intake system & inspect for leaks
• No visual external leaks present
• Engine breather unit allowing smoke to bypass
• Concluded: Inspect condition of spark plugs
• Concluded: Check throttle housing for contamination
• Concluded: Check intake ports/valves for coking
• Concluded: Inspect engine breather system
• Concluded: Program DME with the latest software

1a Inspection of spark plugs condition:

• Remove & inspect spark plugs for all cylinders
• Replaced spark plugs for all cylinders

1b Inspection of throttle housing contamination:

• Removed & inspected throttle housing for contamination
• Cleaned & refined throttle housing

1c Inspection for intake ports/valves for coking

• Remove/refit intake manifold with new gaskets
• Carried out inspection of intake ports & valves
• Carried out a cleaning procedure for all intake valves and intake ports
• Carried out the cleaning of the intake manifold
• Replaced inlet manifold pressure sensor

1d Inspection of engine breather system:

• Removed engine rocker cover & inspected breather
• Replaced engine rocker cover with revised breather system
• Replaced breather system vent house
• Carried out deleting of fault memories
• Carried out resetting of engine adaptations service function

Parts:

• Spark plugs
• 138 House throttle valve cleaner
• Throttle gasket
• Gasket ring
• Intake valve cleaning granulate
• Intake valve cleaning neutraliser
• Intake manifold profile-gasket
• Inlet manifold pressure sensor
• Expanding rivet
• Unter tray spring clip
• Table tie
• Cylinder head cover with crankcase ventilation
• Rocker cover gasket set
• Vent hose
• Petrol system additive

Advisories:

• 1 Faults stored with mixture adaptation - require to conduct mixture control test module - DONE
• 1a Inspect condition of spark plugs: Aftermarket & incorrect type of spark plugs installed - require replacement with genuine spark plugs - DONE
  
  
• 1b Inspection of throttle housing for contaminations:
• Throttle housing very dirty & contaminated - requires cleaning - DONE
  
  
• 1c Inspection for intake ports/valves for coking:
• Require inspection of intake ports/valves for coking & carbon build-up. Will require intake manifold removed - DONE
• Found cylinder head intake ports & valves have excessive coking & carbon build-up. Require cleaning procedure - DONE
• After intake manifold removal, found the following issues:
• Excessive amounts of engine oil within intake manifold - Intake manifold requires cleaning - DONE
• The intake system has excessive engine oil build-up. Require to inspect for defective engine breather - DONE
• The intake manifold pressure sensor saturated with oil & carbon - Recommend replacement - DONE
  
  
• 1d Inspection of engine breather system:
• Early version engine rocker cover installed & breather unit defective - Requires new rocker cover with revised breather - DONE
  
  
• 1e Program vehicle with latest software
• Engine control unit requires programming with latest software - To be rebooked
• The vehicle still on factory software - Recommend complete vehicle programming with the latest software

Additional report:

• Very early version engine timing chain tensioner installed, requires revised timing chain tensioner - To be rebooked
• The engine takes too long to reach/maintain operating temperature - suspect thermostat issue - To be rebooked
• The cooling system filled with incorrect antifreeze - Requires flushing cooling system - To be rebooked

And as I said, the car didn't improve 1%. I am not able to pay anything more due to Corona Virus, my income highly impacted. If I can get your thinking around it maybe I can try to fix it myself (no never tried before, my only relationship with the car filling the gas tank). Sorry for the long post.

Thanks,
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