There are three cylinder head on this compressor the two cylinder warm when the machine is on while the one that i pointed with the green arrows didn't warm compared to the other. Today we are on production while the machines overheat an stop. Please help to troubleshooting this machine

The most common cause for a cylinder not compressing is faulty valves. The intake or discharge valves on that specific cylinder head might be stuck open, broken, or worn out. This prevents pressure buildup and thus no heat generation from compression.

If the valves are fine, the piston rings in that cylinder might be worn or broken. This would allow compressed air to leak past the piston, preventing effective compression and heat generation.

Ensure the connecting rod for that cylinder is intact and properly connected to the crankshaft, allowing the piston to move. A mechanical failure here would prevent the piston from reciprocating.

Check for any blockages in the air intake filter or discharge line specifically for that cylinder. While less common for a single cylinder, it's worth a quick check.

Once the non-functioning cylinder is repaired, ensure the compressor's cooling system (fins, fan if present) is clean and unobstructed to prevent future overheating. Also, check the oil level and quality, as inadequate lubrication can contribute to overheating.