judd944

2 days ago I topped my coolant off and closed the hood. the car sat until last night when I took it for a half hour drive. I got home an put it in the garage. about 2 hours later I came in the basement and there is coolant all over the ground and running out of the garage! I popped the hood and my coolant cap was sitting on the top of my expansion tank...upside down. OK so I either left if off or it popped off. right? but the hoses were empty (upper and lower rad) and the engine was super hot! I opened the bleeder valve and filled the tank. I then had a friend fill the tank as I started the engine to pull the water into the engine. I left the bleeder screw open to let air out. I put the heater on full hot and the air was cold. I then shut the car down. the temp indicated was just below operating temp at this time. Is there anything I should check for before starting my car again?

joseph mitro

check all your hoses and connections. i seriously doubt leaving the radiator cap off would allow that much coolant to leak out. make sure you don't have a split in one of your hoses, which will be very hard to see unless you heat up the engine and watch for coolant spraying from a leak.

judd944

the only way I can see it happened was if the cap was on, allowed it to heat above 100C while pressurized, then the cap blew off and when not under pressure the coolant boiled up and out of the tank.

500

Now that my engine compartment is totally dismantled, I can't check this myself: But, is it possible for the cap to come off AND end up upside down on the top of the expansion tank with the hood closed? Seems to me there is very little room for that cap to flip over.

If you had left that cap off, then most of the coolant could easily have boiled off.

Matt O.

Replace the radiator cap if you think that's the problem. Although, I don't see how that much pressure could cause the cap to blow completely off as it has that spring which allows pressure to escape out the overflow tube. I guess that spring could be bad but I would also guess that spring would go "bad" by getting weaker, not stronger.

In other words, you probably left the cap off.

judd944

hmmm, maybe the thermostat did not open until the car was sitting in my garage after driving, allowing the above 100C coolant to leave the engine, then boil and leave the car. strange. I hope I did not screw anything up.