Q&A

thanks ZeeTech! well after driving the car myself I realized that the temp gauge was randomly going hot.It wouldn't stay hot though,which I suspected was a low coolant concern.When checking it,it was low.topped it off and ran it for a while and it didn't overheat again.No external leaks were found either.One thing that concerns me is that it will idle rough at times,and feels like a miss.The idle speed stays constant while this is happening 5-10 seconds long.Could it be a possible head gasket concern?like it's seaping water into a cylinder/s? have you seen this on minis? The maintenance records on this car show it had a head gasket job 1000 miles ago.

I bet the cooling system wasn't bled correctly after the cyl. head gasket job and that might caused the low coolant and fan staying on situation.
There was a recall for the breather hose on some of the Mini S with the W11 for misfire, rough running, but that use to cause uneven idle also.
If you know someone with a GT1 or an Autologic he could check for smooth running values of each cylinder and compare them. If you have a bore scope you can remove the spark plugs and check the combustion chamber for the sign of coolant, but if you suspect cylinder head gasket leak the best thing would be to pressurize the cooling system for over night with the plugs removed and check the cylinders for coolant. These are pretty much the same steps as it would be on a Ford.
There is usually a decal under the hood if the recall was done by the BMW/Mini dealer : Emissions Recall Campaign Completed.
The recall info:
Recall - Crankcase Breather Line Replacement

SI M11 01 04
Engine

September 2004
Technical Service

PERFORM THE PROCEDURE OUTLINED IN THIS SERVICE INFORMATION ON ALL AFFECTED VEHICLES BEFORE CUSTOMER DELIVERY OR THE NEXT TIME THEY ARE IN THE SHOP FOR MAINTENANCE OR REPAIRS.
SUBJECT
Voluntary Emissions Recall Campaign 04E-A03: Replace Crankcase Breather Line on MINI Cooper S

MODEL
MINI Cooper S from 06/23/2002 up to 07/26/2003

SITUATION

Due to material deterioration, the crankcase ventilation breather hose may soften and eventually may collapse after extended time in service. The customer may complain of a hissing or bumming noise during light acceleration. If the vacuum leak develops due to the breather line deterioration, the "Service Engine Soon" light may be illuminated and various drivability problems (rough idle, stalling) may be experienced.

To minimize customer's inconvenience caused by this Recall Campaign, you may pick-up (and deliver after repair) the affected vehicle from the customer's home, or provide appropriate alternative transportation.

Customers will be impressed when you return their cars cleaned inside and out and with a full tank of gas. Reimbursement information for the vehicle fueling and valet costs can be found in the Warranty portion of this bulletin.
IMPORTANT NOTE :All Cooper S vehicles affected by this Recall Campaign are also in the range of the Emission Recall Campaign 04E-01: Reprogramming DME for Tank Leakage Diagnostic (refer to service bulletin M12 01 04). Make sure that both recalls are performed during the same service visit.

AFFECTED VEHICLES

This Recall Campaign involves MINI Cooper S vehicles with W11 engines which were produced from 06/23/2002 through 07/26/2003.

Beside these, did you checked the spark plugs? Are they the OE NGK plugs?
Here is the info on the plugs:
The spark plug used for the R50, R52, and R53 MINI models, Cooper and Cooper S, is designated
NGK #: BKR6EQUP
Mini part number 12 12 0 030 548
The spark plug used for the Cooper S (R52, R53) with the John Cooper Works Tuning Kit (including the GP version) is designated
NGK #: BKR7EQUP
Mini part number 12 12 0 031 708
This is a quad electrode spark plug design that incorporates a platinum-plated center electrode and four ground electrodes.

Zee