So about a year ago I purchased an 03 coupe. Shortly after it started overheating after a road trip. I changed out the radiator and the t-stat but the car would still over heat. I jacked it up as recommended to get any air out through the bleeder screw and everything, but nothing worked.

That same week I found out my wife was prego and we needed a car asap so I decided to run it without the t-stat in the housing, it worked, no more overheating. Long story short, life got super hectic and never got around to diagnosing this problem until a few weeks ago, the car started overheating again. The car ran without a t-stat in the housing for about a year ( I know, no Bueno). I've done a hydrocarbon test and checked my oil for coolant and seen nothing, fans look to be running fine. My only guess now would be the water pump?

Any advice is greatly appreciate, thanks in advance guys!

 

Does it overheat all the time like when idling or while driving as well? The thermostat is still out? How long did you bleed the air out? I usually do it for about an hour or more.

Double check the basics:

Air and coolant level

Water pump is driven by the chain and unless the impellers broke or somehow the shaft got messed up not sure how you wouldn't know. When my water pump went out it was the bearings and it would scream real loud.

Most recent overheating issue I had was due to my cooling fans. They would only spin at low, so my car would overheat at idle, but not while going highway speeds.

 

On my 04 g35 I had my mechanic couldn't get all the air out from the radiator and the car will overheat he gave up and took out the thermostat and everything worked fine but the heater stop working

 

Need to buy a Lisle funnel if you ever plan on burping air out of the system. Rev the engine and you'll see bubbles coming out. I had air pockets big enough to splash coolant all over the engine