So I go down to Emissions my 1992 Camaro Z. I just got done installing an aftermarket temp. Gauge. She ran around average driving down the road (180-220) depending on speed. Then I drive into the Emission lanes and she starts heating up. 225-230. The guy pulls my car onto the Dyno does the first run. Stops then does the second chance run. MY lower radiator hose leaks a little...well a lot but none the less. This "Technician" of theirs shuts the car down and she is pissing steam out from the hood so they push it off the dyno, Give me my failed tests. It was High on CO and HC. I start my car and the New gauge was almost peaked at 260. You think they would have been like uhh no. Thats to high i don't want to blow this dudes motor. So my Question is WHY THE EFF is my car overheating. Yes the Air Dam is there, "No my radiator is not Blocked, Yes there is a new thermostat on her. Fresh coolant flush. MY fans I have no idea. When i click my key to "On" they come on but not at full speed kinda like half speed. I was looking to see where my lower hose was leaking (Hose or Clamp or cracked WP is what i was checking) While I was doiing it I noticed a little puddle of coolant on to of the WP right next to a little hole(See picture) and it was hissing and spitting out some coolant. What is this little hole? Now im thinking if my car was running at NOT it would have passed. But I need to figure this out. And to all the people that suggest to just "rig my fans to stay on all the time" NO NO and NO it is overheating cause something is WRONG! What is wrong im not to sure. Thats why im here. How do i test my fans they do spin. But they always spin.

 

Sounds like a new water pump and possibly fan motors may be in your future. Typically when water is coming out of that weep hole your seal is gone, you are losing water, and no longer maintaining pressure. I don't know about the half speed fans but that could be fan motor bearing related also.

 

^^^
If the system lost pressure, this would cause overheating. Looks like the wp chose that exact moment to let go on you, like a good thirdgen