R55 Mini Clubman Issues

[titch2k6]

Hi.

Looking for some advice as I have exhausted searching through other forum posts.

My friend has an R55 (2007) Mini Clubman that is dying when the engine is hot (dies at around the 89 - 92C mark due to loss of idle revs). The car will restart after dying, but there are no idle revs and the car will just die again after taking the foot off the accelerator and the revs dip.

OBD is not showing any fault codes and has no engine management warning light.

MAP sensor was recently changed after a number of fault codes popped up (all now running fine with no more codes appearing), plus the matrix heater was exchanged after the cabin heat was lost (original matrix was clogged) and the system fully bled on refill.

The car is running at around 800-900 rpm on a cold start (whereas I believe it should be around 900-1100 rpm), and as the engine warms, it will drop to around 450-500 rpm at around 60C. Scanning also shows the revs are fluctuating quite a bit (not to the point of engine "purging"). As it gets hotter, this will drop even further until it cannot hold idle revs.

Temperatures will reach 103C with no fan action whatsoever (not sure if Stage1 kicks in prior to this point or not, but guessing it should?).

I am at this point suspecting a faulty ECT sensor and will be checking this, but I cannot find any information on the ohm/temp values specific to this vehicle. Also, are these symptoms something that may be related to the electric thermostat? I believe the water pump is working as the matrix gets very hot (it is like an oven in the cab when the engine is running hot, furthering the impression that overheating is the issue and the ECU is incorrectly mixing fuel and advancing the engine based on bad coolant temp info).

I took the car to a dealer's so-called "technicians" and they were more than useless........

Does anyone have the data for resistance/temp on the R55's ECT sensor and, if you have experienced similar issues, did you manage to resolve the problem and if so, what worked for you?

Many thanks in advance for any advice.