Temp gauge All over the place, Air in coolant lines

[2k Escalade]

I own a 2000 Escalade which I did a coolant flush and replaced the T-stat. I've been able to narrow it down to when the vehicle will start to increase in temp. It will rise all the way to 260 for a moment and then it seems the T-stat will drop it back down to just below 210. This seems to happen under a light load approx. 20-30 MPH 1000 - 2000 RPM's (Usually after sitting at a light) I hear running water in the cab when I drive so I'm sure there is air in there, or it could be clogged still, How do I resolve this once and for all? Thanks all.

 

[oh1yukonslt]

I own a 2000 Escalade which I did a coolant flush and replaced the T-stat. I've been able to narrow it down to when the vehicle will start to increase in temp. It will rise all the way to 260 for a moment and then it seems the T-stat will drop it back down to just below 210. This seems to happen under a light load approx. 20-30 MPH 1000 - 2000 RPM's (Usually after sitting at a light) I hear running water in the cab when I drive so I'm sure there is air in there, or it could be clogged still, How do I resolve this once and for all? Thanks all.

What T-stat did you get? I have seen aftermarket ones fail right out the box. And did you do a complete flush of all lines ie: Heater core? Or worst case could be a failing water pump. Hearing water does indicate air in the lines. Are you losing any coolant?

 

[Rivieraracing]

When hot and cold, what are you coolant levels in the reservoir? When hot, are both top and bottom hose equally hot? When you say the gauge is all over the place, what's the typical range of temps it shows?

 

[2k Escalade]

The thermostat was just a $7 part at autozone. Im almost positive I got a failsafe. it seemed to have fixed part of the issue. But as far as flushing all the lines I wouldn't know if I did. I removed the lower radiator hose emptied all the junk. replaced and refilled with a flushing agent and water. let it run, then drained it and ran water throw the system with the lower hose not attached. I haven't been able to tell if I am losing coolant anywhere. or if air is being introduced somewhere. ive been trying to burb the air out when the vehicle is cold and Check the radiator coolant level. for the majority the vehicle runs top notch except when I lose heat for a moment and the temp goes way up. it always comes right back down to normal after a few minutes. but im concerned of it even getting that high. coolant levels are normal in the recovery tank depending on engine temp. I didn't follow any particular orders when refilling the coolant. I made sure I filled only 1 gallon first and let the vehicle sit with the radiator cap open. I figured the air will be able to find its way out if its not weighted down by too much coolant. other than that I filled it, it ran fine and coolant circulated.