Hello, I'm new tto this web sight nice to meet everyone. My name is randy and while I don't personally own and drive a B.M.W. my brother in law just bought a 1997 B.M.W. 740 il. I do a lot of his car repairs so I signed up for this web sight. heres my question. His car recently started running hot. It got so hot that it blew the top off his reservoir. he has replaced it but it still runs hot. I imediatetly think that has a bad thermostat. However I've been reading about burping the system. This is something I've never heard of before, can burping the system really stop it from running hot?