I bought a sexy black 1996 BMW 318is about a year and a half ago under the impression that it only needed a water pump. I replaced that and the thermostat and the heater core and then drove it a handful of times; it then began to rapidly overheat (the gauge went from normal to way too hot in 30 secs)! Turns out the previous owner had failed to mention about the shotty engine work (head gasket) he had done. I then replaced the motor with a used one from a 99. Burnt again. The mechanic I paid to do it, spliced all the wiring harness. Now it runs but not well. It idles at 3000 RPM and then dies and when driven it seems to be in limp mode. I am out of ideas as far as troubleshooting and am about to throw in the towel on this one. Any ideas? Anyone want to be the proud new owner??