05 Cooper N/A
Car has been to multiple shops for overheating and a coolant leak. Every hose has been replaced, has new water pump, has new thermostat, has new cap. Passed multiple block tests and pressure tests. Holds 15 pounds [practically] all day. Has Mini approved coolant with proper mixture. No visible leaks anywhere.
Cooling system holds only around 8-10 psi while running. Will eventually (time varies from 10 minutes to an hour) build to 14-15 psi and then suddenly begin to overheat very quickly and drop pressure to around 5 psi. Place of leakage varies.
I'm suspecting cracked head/block or bad head gasket but shows none of the typical/easily diagnosed symptoms of these problems.
IATN or Identifix anyone? The shop I'm currently working at doesn't have either and neither do I.
Any help would be greatly appreciated.