looking for feedback on an apparent problem with an '05 UK spec R50 Cooper Park Lane. (Not that the Park Lane bit has anything to do with the problem, I'm just showing off while I still can
Motor has done just over 37K and most things are fine. However last year coolant was disappearing and fault traced to you guessed it the thermo housing. This replaced and all's well. In retrospect there may have been a bit of a 'wait' before the coolant loss was identified but we dont do very many miles (less than 4.5K pa) however although never redlined perhaps it got cooked?!
In any event now a good 8 months since the thermostat housing was replaced coolant going again - approx 11mm drop in the reservoir for 60 ish miles at moderate (50 - 70mph) speed was noticed recently. Looking into the reservoir which had gone empty I did notice collant right at the bottom but this had an olive complection. Topped up and just over (by 11mm) before the 60mile journey I mentioned just now. Was hoping to see coolant a good deal dirtier at the end of 60 miles to help confirm oil into coolant leak somewhere but not really the case. Taken it to mech who did the thermo housing renew. He runs a clean and tidy unit and although he agrees the 'olive-ness' which is realy only down at the bottom of the resevoir of coolant is an oil deposit. Not sure if I am altogether convinced. There is no sign of milky deposit in on the oil cap. Mech says there is only one way of telling of a leak and thats to pressure test cylinders but that will only show water into oil which I dont have. He knows of no test for oil into water/coolant. Is he right??
What can I do about this coolant loss and have I got an oil leak to boot? He suggests continued use of the car with careful monitoring. I dont want to throw a cash mountain at this unthinking and uninformed.
So what are my options? Could anybody please help shed some light here please! Surely there are some tests I can run to see where the fault lies...
I need the car in perfect working order for when I do use it so any advice gratefully received.
PS: Just to add between the thermo housing change and this problem the vehicle was involved in a very low rolling speed collision and the aircon rad appears (to me now) to have been replaced.