BMW E32 radiator, leaks and overheating
My E32 is leaking coolant under the car, where does the leak usually come from?
Common leak points are the plastic joint at the top of the radiator and a crack in the plastic end tank, the drain plug at the bottom edge, and an old water hose with a hole under the clamp. The plug may leak just because it is loose. A leaking hose and the clamps are replaced with new ones.
Why does my E32 overheat even though there is coolant?
The cause can be a faulty thermostat, a broken expansion tank cap or a water pump that does not turn properly. The thin bleed hose between the radiator and the expansion tank can also be blocked, so air cannot escape and the coolant does not circulate. The hose is blown clear.
How do I bleed the E32 cooling system after a repair?
1. Open the bleed screw on the thermostat housing. 2. Add coolant until no more air comes out. 3. Close the screw and check the coolant level. Bleeding is always done after replacing a part, and only then do you test drive. Bleeding is difficult if the circulation pump is in poor condition.
Can the cause of overheating be the head gasket?
It can. If exhaust gas gets into the coolant, a workshop can measure it from the expansion tank. The measurement shows whether pressure is coming from the combustion chamber into the cooling system. It is worth confirming this before the cylinder head is opened.