My 2002 GTP has been having the low coolant light come on and turn back off multiple times while driving, in addition the temperature will range from normal to 3/4 of the way up the gauge after it's warmed up. 2 years ago I did the LIM job with aluminum elbows and all has been well since then, this is a new development. I've added coolant to the reservoir as well as topped of the rad when the car was cool. Any other ideas?