Overheating z3

[Zaniei3]

Hi all, after changing the oil pan gasket my car started overheating after driving 30 min or so. I have to idle at high speed to bring down the temp, first thing I did was to change the fan clutch but still the same issue. Touched the top hose from top of radiator to water pump and it was lot hotter than the one going to the bottom of the radiator so i figure is the thermostat. Ordered one and should arrive tomorrow.
Also read somewhere if you open the water reservoir with car on and you see bubbles then your water pump is working ok but I surely hear a sound like crickets coming from water pump area. Any other way to diagnose this issue? Or find out if my water pump is bad?
2002 z3 roadster 3.0i

 

[Rudyrov]

Usually, when a water pump goes bad, it will leak water out of the pulley support bearing, this water will come out of a weep hole on the pulley support snout.
Sometimes impellers will also fail especially if they are plastic.

 

[Zaniei3]

Usually, when a water pump goes bad, it will leak water out of the pulley support bearing, this water will come out of a weep hole on the pulley support snout.
Sometimes impellers will also fail especially if they are plastic.

Thanks. No leaking here. So hopefully is the thermostat

 

[Rudyrov]

An infrared thermometer makes it easy to verify. At roughly 190 to 200 F the Thermostat opens and the cooler hose get hot. If it doesn’t happen then usually a thermostat is at fault.

 

[Zaniei3]

Thanks guys. It was the thermostat, All good for now.