1998 BMW 528i overheating?

I took it too my mecanic hi told me that it is the presure inside the coolant sistem .Hi took the presure out and added some more antifreeze and it stoped for one month. Now it started again.i want to take it to the dealership but before i do iwant to know what is the problem .thank you

1998 BMW 528i overheating?computer repair

BMW are hyper sensitive to cooling problems. The main thing that mechanics overlook when working on BMW's is properly bleeding the cooling systems. I would suspect that this is your problem. I would take the car to BMW and have someone check out the cooling systems. Again BMW's are very heat sensitive, 9 times out of 10 if you overheat a BMW you will have damaged the head or head gasket. A BMW dealership will be able to check the coolant to see if any exhaust is in the coolant. This would be a sign of a head/head gasket failure.

Common mistakes when bleeding BMW cooling systems, identify the number of bleeder valves and bleed off all of them. Verify a positive flow of coolant, both the flow and return hoses will pressurize and heat up, passenger cabin will have heat, engine temp gage will remain in the normal area (around 120c).

Make sure passenger cabin heater controls are on max.

Next commonly overlooked problem is the fan clutch, BMW's use a thermal switch on the fan clutch, the fan clutch should engage when the vehicle reaches a temperature of 120-160 degrees Celsius.