While I got rammy yesterday doing LT install and snapped that sensor. I picked up a new one today put everything in, refilled coolant, bled everything out and filled everything to the right levels. I was standing outside idling the car to burn off the paint and heard gurgling. Jumped in car saw the temperature gauge in the red so I shut it off really fast. Searching other posts here I have done everything I was supposed to as far as bleeding off the lines and refilling the coolant. Could the sensor I put in be causing my problems? Any other ideas?

 

I am thinking you mean the temp sensor in the head, and not the one in the waterpump. There is a possibility the sensor is screwing up - but I would say it is more likely that the system is just air-locked. How hot did the engine seem when the guage was in the red? The coolant should have been pretty much boiling....

It can take a long time to get an air pocket out of the cooling system. When I did my last waterpump intsall - I bled the system forever and it wouldn't release for over 20 minutes. My temp guage kept climbing over 220 - and I was beginning to think that I broke the spline in the waterpump and it wasn't circulating water. But FINALLY - the air pocket let loose and it cooled right down. So try bleeding it some more first, then evaluate other issues (sometimes opening the bottom pedcock on the radiator will get the air out also)

 

It sounds like an air pocket to me as well, doubt it is the sensor.

 

There are 3 coolant sensors on the LT1. It sounds like you nailed this sensor. ECT to Cluster


The other two coolant sensors are:
1) ECT to ECM
2) Low Coolant Sensor

If you heard gurgling, then you've got a concern regardless of the gauge. Is there a coolant leak? If not, then it is likely an air pocket... let's hope.

Did you open the bleeder valves when you added coolant after replacing the sensor? Then run the engine with the valves open... use a rag to protect your opti.