Engine too hot?

[MNE30]

I'm trying to diagnose why my engine is running to hot (M20B25). Currently after driving it to a warm running temp it gets to about a little smidge under 3/4ths on the gauge which is a bit high from previous experience.

Here are some things to look into:

1. No puller fan on the radiator, P/O thought it was part of the A/C and deleted it along with the A/C pump (stupid I know) but even at higher speeds (50-60mph) it still is hot which leads me to believe that isn't the main issue.

2. Low coolant level, still coolant in the engine though.

3. Would air in the coolant system cause it to run warm as well? Because I'm almost positive that it needs to be bled because one of the tubes running from the intake manifold has a small leak that just barely drips.

Basically the whole cooling system is ridiculous. Would running with air in the system cause it to run warmer than normal? The radiator is actually in good shape, but I'm figuring the price of a new radiator and hoses isn't exponentially high. I have a fan clutch, just picked one up, but no fan.

[Wh33lhop]

Running with enough air in the system would likely manifest in the temp gauge being erratic, not steady-state hot. If it is steady and consistent at that temperature (through hot and cold weather and all speeds), it sounds like a thermostat or maybe even a temp gauge/sensor inaccuracy, though the former is probably more likely.

[jlevie]

At speeds of over 35mph, the engine driven fan isn't a factor in overheating. A clogged radiator or bad thermostat are the most likely candidates. Enough air in the cooling system to cause problems at speed will usually cause a melt down at idle.

[Cephas]

Fix the main issue first. You need to bleed the system and get a fan on there. After that we can diagnose further. My temp gauge was inaccurate because the nut on the back of the cluster was loose. It could be a ton of things, but you need to start with the most obvious.