My son's 2010 Civic DX-VP has a major issue with overheating during a long drive or anytime it is going faster than about 60. Runs about 2/3 to 3/4 of gauge normally, but tops out when under any load. Must implement mass heater-blow to cool down.

• Originally, we discovered a seam leak on the radiator and replaced it and both hoses.
• The fan blade had also disintegrated and we replaced the unit. Still overheated.
• Replaced the thermostat and the lower ECT.
• Replaced the ECM and had it reprogrammed/updated by Honda dealer.

• All relays are good
• Fans run appropriately
• No water in oil
• No condensation under filler cap
• Coolant pressure test -extremely slow leak down-about one drop/2 to 3 minutes external to engine
• Runs well
• Compression check

Idle ~3000 rpm
#1 70 108
#2 70 105
#3 68 112
#4 66 103