Never leave the cap loose. You are keeping the recovery tank from depleting but the cooling system is losing fluids through the cap and you are not going to notice it until it is too late.
The cooling system works under pressure and the main purpose of the cap is to keep the pressure constant.
Depleting in 2 days means the leak is not too big to drip but should be sufficient to show with a pressure test. I don't understand why the leak cannot be detected. Was the heater core checked?
Try a dye test.
If pressure test is done with warm engine and did not show anything, do it when engine is cold. Keep attention on hose joints.
Monday, April 15th, 2013 AT 10:02 AM