I need some advise on my 2001 X5 4.4i. Here is my situation, I had friend flush the radiator and put new coolant on it. I believe he did not flush it properly by bleeding out all air bubble thru bleed screw. I notice there was a leak thru lower radiator hose right at the sensor area, then I had the hose replace, after that no leak but I notice the lower hose is not as hot as upper hose even I was driving for a few hours. I was told that it might be thermostat, then I had thermostat replace. However, the symptom is still the same. Can someone tell me whether my car is ok to drive. So far, I've been driving for two weeks and it is not overheat at all but sometimes I smell kind of coolant. I know that it could be a leak somewhere but I don't see any leak on the floor at all. Here what I worry after a couple hours drive, I notice the upper radiator hose is very hot and lower hose is just warm. I am afraid the upper hose is going to blow some day. I had everything replace except water pump. If water pump problem, why there is no overheat, the temp guage remains at the middle. Please advise. Thank you very much for all info or help.