Hi all, I'm barry! I have a BMW E46 320D 2003 & when I drive constant and switch off and shortly after want to start,and the intrument panels come on the heat gage shows in the red and won't start but the car is not overheated as such. Sometimes when I switch the ignition on & off a couple of times the temp gage will show normal in the middle and wil start then.lately its getting worse & the other day was stuck like that for 45 min. Had diagnostics done & when it is like that shows faults like glow plugs, pressure rail and temp at 101 'c but a minute or two later when turning the ignition on & off and comes to normal the diagnostics shows no faults & 86 'c all normal. They told me maybe water pump so I left it by them now they say it might be the computer box which costs an arm & a leg here. I don't know anymore so pls help!