Overfilled Radiator?

[stevil69]

Hello Good People,

Last night I filled my radiator with coolant. I was doing it with very little light, and so I filled the radiator close to the top.

This morning, I drove for about 20 minutes, and the bottle neck attatched to the radiator (which the upper hose is clamped onto) broke off, sending my car ovearheating and coolant spilling all over the place.

So, my question is, could have my filling the radiator too much have caused the little plastic neck to break off? If not, does anyone know what could have caused this?

Thanks.

Steven

[323imankiks]

possibly waterpump, or thermastat are bad. I dont think overfilling would do that maybe someone else knows better. i think some 5 series radiaters have weak necks on them commen to break

[FiveCarsRule]

323imankiks is right about the radiators having weak necks. If you browse around some you'll probably see tons of posts concerning this problem. The plastic neck that the hose connects too is really weak. It breaks often on early 90's cars, most likely because of it becoming brittle over time. Oddly, overtightening the hose to the neck won't break it immediately, but i doubt its good for it. I had this same problem on my 90 535i. Bottom line is that overfilling the coolant did not blow up your radiator. I just bought a new radiator ($200), not sure if you can replace the neck (doubt it). While you have the radiator out probably a good idea to check the thermostat and replace all the coolant. Early 90's beamers seem to have a few cooling problems.