New car, temperature issues

[Got Mayhem?]

Hi all, Just picked up a 91 318i to replace the one a tree so swiftly took away from me this winter. It only took a minute of running before a coolant line under the intake manifold came off and shot the temperature up. I was in the car playing with some electrical stuff so I didn't immediately notice the coolant, but stopped the car before it overheated. I fixed the line and started the car again. However this time the temperature gauge does not go up, no matter how long it runs for. I've determined that coolant isn't being blocked and the water pump seems to be fine.

I did try to allow air to escape the system. Maybe I should try again? All I could think of is that there is a bubble left somewhere but maybe I'm missing something.

Thanks ahead of time guys!

Edit. Tried bleeding it for a third time, I think it worked. The gauge now goes up, but it seems to be running hot (3/4+ of the gauge). When driving it goes down to just at the blue. I'm not worried about overheating really but I feel like something is still off.

[Geoff]

be very careful here.  when the guage does not function, it usually is because there is no fluid around the sensor, which is in the head. because a hose came off while the car ran,  I would suspect this  to be the case. there may be an air block of the system, even tho you bled it ,because these systems can be a bitch to bleed.  try that again,  and try using the lower bleed valve first,  till all air appears to be out,  then the upper valve,  holding the engine at a fast idle, or 2500 rpm or so, till all air has left the system.   seal it back up, and drive the car a little, locally,  to keep an eye on the guage.  if you still have problems,  maybe you have a bad thermostat, or another blockage somewhere, and be sure the heater valve is open all the way when bleeding the system
                                                                Geoff

[Got Mayhem?]

be very careful here.  when the guage does not function, it usually is because there is no fluid around the sensor, which is in the head. because a hose came off while the car ran,  I would suspect this  to be the case. there may be an air block of the system, even tho you bled it ,because these systems can be a bitch to bleed.  try that again,  and try using the lower bleed valve first,  till all air appears to be out,  then the upper valve,  holding the engine at a fast idle, or 2500 rpm or so, till all air has left the system.   seal it back up, and drive the car a little, locally,  to keep an eye on the guage.  if you still have problems,  maybe you have a bad thermostat, or another blockage somewhere, and be sure the heater valve is open all the way when bleeding the system
                                                                Geoff

Still no luck with bleeding it. The car idles where it usually does when it's warm after running for a bit. The gauge is resting right above the line on the cold side after running. Thanks for the ideas, maybe i'll give it another bleed later.