Got a picture of the system?
Any idea of what the actual flow rate through Loop 1 is?
Any idea of what the water temperatures are?
What is the temperature of the air that enters the radiator?
What is your estimate of the amount of air-flow that the radiator is actually receiving?
Basically more information is needed. Given your high(ish) idle and load temperatures it seems to me that you have a flow-rate and/or a radiator issue.
Please try to gather all of the above.
|