Engine overheating warning sounded. Looked at indicator and it was all the way in the red. Pulled over immediately. 30 seconds later the radiator blew with the force of an explosion, shooting coolant about five feet across the street even though the hood was down. Opened hood and found a hole in top of radiator, more than an inch in diameter. I would have opened hood before it blew so I came within half a minute of being badly burned. My mechanic said it happens regularly with BMW 525's. he said it happens around 80,000 miles. My car had 75,000 miles. Mechanic said he testified in a case a few years ago where an owner was badly burned. He had a box with a bunch of pieces of radiators that had failed. I kept my radiator as evidence. None of the hoses failed but the radiator blew a hole out of the top. It is made of plastic and is only about an eight of an inch thick. I would expect that any point of connection such as a hose or a seal would bust under pressure before the radiator itself would fail. I'd never heard of such a thing happening in 30 years of driving. I believe this is a dangerous design defect, either in the material used or it's thickness. Though the repair cost almost a thousand dollars I felt lucky because I knew that I opened the a half minute earlier I could have been extremely badly burned or evened blinded. The force of the explosion was incredible. I'm less concerned about the money than about somebody being seriously injured by this defect.

- Sacramento, CA, USA