Smoke Screen

How big is your cooler? I.E. 4x6, 8x10, 10x12, etc.... My cooler lines run pretty close to one of the header tubes also and it doesn't cause an overheating issue. It's generally a small area where the tubes are close to the cooler lines so in most cases it's not a problem. I'd suspect your cooler is just too small or possibly located in a spot where it's not receiving proper air flow. If you use only an auxiliary cooler it can cause overheating problems in stop and go traffic cause there's not enough air flow past it.