Broke down!!!

[bimmerboi18]

Last week and every week before my car ran fine, NEVER a problem. Two days ago, the check control says "Engine oil Low." So I add a quart of oil. It says it again, so I add another quart. Then again it says it, so I add another quart. Today I am driving down the interstate everything seems fine, temp gauge is fine. When all of a sudden a loud chime, "COOLANT TEMP" then the temp gauge jumps to hot in the red. So I kill the engine and coast to a stop. Add coolant, let the car sit an hour in the baking sun and then start it up after the gauge says its cool. Well, within one minute of driving, the gauge jumps to red, and the warning chime comes on "COOLANT TEMP" So again I kill the engine and coast to a stop. Only this time, when I opened the hood, coolant was FLOODING out of the bottom of the radiator. So I called roadside assistance and they came and towed it to my mechanics garage and drove me home. Any ideas on what the prob is? Its a 92 525i M50, with 165k miles. Thanks guys! BTW, the engine oil low light never goes out, ive added like 4 quarts. and where is the full mark on the dipstick. The two lines?

[dacoyote]

The full mark is the top of the two lines.

Is / Was there was any OIL in the coolant, is there water in the oil? It could be a head gasket or the like.

Has the water pump been changed out to one of the ones with metal impelers?

Thanks

Charles

[Kalevera]

Were the quarts of oil just....blindly...added or was the level checked? The level sender is probably bad, or the connector's corroded. Either way, overfilling the oil is a bad idea. At normal operating temps, the gasses produced by the oil have nowhere to go.

As Charles intimated, the plastic in these cooling systems (especially the plastic impeller'ed water pumps) creates problems. The water pump or thermostat (probably the water pump, though) likely failed as the car was going along the highway. The dash temp gauge isn't reliable: it has about 60 degrees of variance in it before the needle will start to move -- this was done to prevent customers from freaking out when the gauge inched up a bit while sitting at a stop light; the car was probably overheating a bit before the gauge went to the red. Starting the car after it had overheated only exacerbated the problem: the high temps = more pressure in the cooling system, already affecting (likely) brittle plastic parts, caused the weakest point to go, in this case the expansion tank or some other radiator component.

best, whit