Overheating I have a 93 325i , I have replaced the thermostat , thermostat housing,radiator,fan, fan clutch, waterpump and the head gasket and it still over heats ! What can be the reason that it is still overheating ? My heater doesn't blow warm at all either.

thermostat --waterpump---radiator--low coolant--head gasket

A hot running engine is usually caused by a cooling system problem. Make sure the coolant level is full and the thermostat.. rad fan.. radiator cap and water pump are all functioning correctly. Make sure there are no restrictions in front of the radiator to obstruct air flow and coolant circulates properly throughout the radiator. As for losing oil, check for the obvious..... Leaks. If no major leaks and you have a high mileage engine, suspect the oil to be burning within the engine. A constantly hot running engine can also cause the oil to break down quicker resulting in consumption, especially if oil changes are neglected

chek if the electric fan is turning on when the ac is turned on

could be a number of things, 1. water pump not working 2. Thermostat stuck (replace if its boiled) 3. air lock in system. 4. Head gasket. 5. cracked head/block. I presume you have checked that you belt is not broken, are there any signs of leaking around the waterpump? if there are, change the pump, If the engine has overheated, change the thermostat. these are the most common things, other than these 2 it is going to take further examination for cylinder head problems or blocked water ways. Go for the thermostat first, its probably the cheapest part to replace, and see if that cures your problem.

yes, there is a thermostat. That's a good place to start.

Please see my tip at http://www.fixya.com/cars/r5929960-s_thermostat . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me.

Did you bleed the cooling system after refilling the radiator ? to bleed the system, fill the radiator with water and coolant. Run the engine until it is at a good temperature. Then turn off the engine and look for a bleeding screw at the oulet of the thermostat housing and turn it with a screwdriver counterclock wise. The trapped air will go out and coolant will start coming out. refill the radiator and repeat until only coolant comes out and no air.be careful not to burn yourself.

1 Inspect Cooling System Mix Coolant level low or flow is restricted. 2 Inspect Belt Incorrectly routed, adjusted, tensioned, missing, or worn water pump belt(s). 3 Inspect Oil Pan Gasket - Performance Ruptured, cracked or leaking radiator hose. 4 Inspect Radiator Cap Worn or damaged radiator cap 5 Inspect Thermostat Thermostat stuck closed 6 Inspect Fan Blade Broken, missing, or defective fan blade(s). 8 Inspect Water Pump Damaged, worn or leaking water pump. 9 Inspect Intake Manifold Plenum - Perform Leaking water pump gasket. 10 Inspect Cooling Fan Control Faulty cooling fan control or circuit. 11 Inspect Cooling Fan Switch - Radiator Faulty radiator cooling fan switch or circuit. 12 Inspect Engine Temperature Sensor Faulty engine temperature sensor or circuit. 13 Inspect Temperature Switch Damaged or faulty temperature switch or temperature switch circuit. 14 Inspect Fan Clutch Worn, loose or faulty fan clutch. 15 Inspect Ported Vacuum Switch Damaged, leaking, or faulty ported vacuum switch. 16 Inspect Radiator Obstructed radiator core or radiator cooling fins. 17 Inspect Head Gasket - Performance Head gasket leaking coolant into cylinders

sounds like u might have a blown head gasket is your oil milky colored

check o see if you have a cracked haed or blown head gasket

Could be a head gasket. If it got hot enough, it could have warped the head. Costs from $1900 - $3000.