Seems like the high-side pressure is too high
The refrigerant needs to be operating at the right pressures in order for the air-con to function properly:
- If the pressure is too low, there is risk of compressor damage in addition to lack of cooling
- If the pressure is too high, the effectiveness of cooling diminishes at the very least
To avoid hitting issues related to this, modern air-conditioning circuits are equipped with a pressure switch/sensor. Its job is to protect the system from self-destruction by preventing the AC from running under the wrong conditions.
Based on this scrap of information on the ETCG forum, it seems that Mitsubishi utilizes both low-side and high-side pressure switches on the Lancer:
While I cannot promise the values will work for your Lancer due to regional variations, the fact that there is a high-side cutoff can explain the AC not working above 3000 RPM.
What's so special about 3000 RPM?
Compressor speed depends on engine speed. The higher the engine speed, the faster the compressor spins. The faster a compressor spins, the higher its discharge pressure.
It looks like around 3000 RPM the compressor is able to nudge the high-side pressure past the allowable limit, causing the switch to intervene and disengage the compressor clutch (hiss...).
Where to look for the smoking gun?
Given the symptoms and maintenance history shared so far (non-OEM replacement compressor, refrigerant recharge), there are two possible culprits:
non-conformant compressor specs
Specifically, the compressor employed is not fit for the Lancer because it is increasing the pressure too much.
too much refrigerant in the system
More refrigerant, more system pressure. Less refrigerant, less system pressure.
- Measure the low-side and high-side pressures of the system if possible
- If possible, find detailed specs on your Lancer's AC system like in the image above. There is a good chance this information will be presented in the owner's manual.
- If information found, have the system evacuated completely and have the right amount of refrigerant (by mass) refilled.
- If information not available, have some refrigerant removed try to match the pressures on both high side and low side as best as possible.
- If the difference between low-side and high-side is too much regardless of the amount of refrigerant used, chances are that the compressor is not a good match and it needs to be replaced with one more suitable for the Lancer.
All the best.