BMW Repair: BMW 1991 316i, coolant level, temp sensor

Question
Just had a new fuel pump put in my car, drove it for about 1 1/2 hours before i noticed the engine temp  was a little high, then as i started to move forward in 1st the revs would hit 2 1/2 thousand before the car moved whilst also shuddering. The engine shudders in 2nd and 3rd gear as well. I found that if i changed from neutral to 1st start pulling away then change back to neutral then 1st again the problem would go, however then i stop, put it in 1st start to drive off and the problem happens all over again! Please help!

Answer
Adam,
 First off, make sure not to drive the car if the temp is climbing.  You will be replacing an engine pretty soon otherwise.  If you see the temp reach 3/4 (75%) pull over and cut the engine off.
  
 The second thing is that these systems use a temp sensor in the thermostat housing that tells the ECU when the engine is up to temperature.  If this gets too hot, it can affect idle and make the engine run weird.

 Check your coolant level and see if it's low, if it is... that's likely your problem
  
 Hope this helps,
 Josh