2000 BMW 528 overheats


My 200 BMW 528i is overheating . At some point the serpentine belt and ac belts broke and caused the car to over heat. I had to replace thr radiator, radiator resivour, both belts. The “mechanic” returned the car to me 3 times still overheating within 1/2 mile. This car has not had any major problems before. I know ( squat) about mechanics

It could be the head gasket gone, they don’t like being over heated and can also damage the head. It may be something as simple as they didn’t bleed the coolant properly, they get airlock’s in the system very easily so if you don’t know what you’re doing you’ll never get it bled successfully.


The water pump could be bad, they should have replaced it when they replaced all the other stuff.

Your “mechanic” replaced the radiator and did not do a 1 mile test drive for overheating? Did you tell him it was overheating? And he said what?

I think it’s very likely to be the water pump.
If it’s an electric pump, even though it’s not covered by this Class Action Suit, that lawsuit gives you some idea about how common electric water pump failures are on that make:

I respectfully suggest that you find a new mechanic. IMHO, returning it to him once wouldn’t be a cause for major concern as long as he fixed it on that return visit, but if he failed on 3 return visits to properly diagnose the problem, then he isn’t much of a mechanic

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If it overheats within a half mile then I suspect a faulty gauge or a thermostat that is stuck closed on top of the water pump as mentioned.

I would not be terribly enamored of a shop that replaced all of those items and did not test it after the repairs while also not considering a possible faulty thermostat or water pump.
And to do it 3 times? Ridiculous.

Just my opinion, but I consider a thermostat a maintenance item to be replaced at various intervals. That’s one of those better to be proactive items rather than find out at midnight while in a suspect neighborhood or a 100 miles from nowhere.

did anyone check to see if the radiator fans are coming on?

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If the engine compartment fans are working, and the coolant has been air-bled, the next step is probably to pressure test the cooling system. There may still be a small leak which is preventing the system from reaching the proper pressure. That allows the coolant to boil, which will cause overheating. The pressure cap should be tested at the same time.

I’e never had a water pump that completely quit pumping. Usually when mine fail they leak first. If I wondered if the water pump and/or thermostat wasn’t working on either of my vehicles (my not apply to yours) I’d just remove the top radiator hose and see if water really poured out when the engine reached normal operating temperature.