Hello all, I've looked throughout the threads and various resources online and have no idea on where to go to get an answer. You guys seem the most knowledgeable and I have been able to pick up many pointers from audiworld so I figure this would be my best bet at finding an answer. Here is my detailed situation. Bought a used 2001 A4 1.8t FWD. Looks like the previous owner had made a few mods to it and now, I guess I am left in the dark to figuring out why the car is overheating. Here is what I have checked and what I have done, hopefully someone can tell me what I need to do or what I did to make this happen. Heres what happens: Got the car about a week ago, have since put about 200 miles on it, was fine at first but now it seems as though at idle the car overheats, it goes over the midway point on the gage when I am moving, but just barely over the line. The ram air seems to keep the engine cool enough when moving and it's not like the temp spikes up in seconds but a few minutes at a light makes the temp go up a notch. Both fans kick on when they are supposed to (so i assume it's not the t-stat), coolant levels are fine with no leaks in the tank or hoses, ac comes out cold... Could it be my water pump? Is there a way to check that out without ripping the frontend off and getting into the nitty gritty? Here's whats been done: Seems like the previous owner had a manual turbo controller setup, cant really tell what the setting is at as I haven't set it up with a boost gage or taken it to get checked, could this be doing it? Also, I had put in the lucas gas treatment stuff as the mechanic that I talked to recommended since it was sitting for a couple months before I got it, could this be doing it? Also, I bought some of the Advance Auto Coolant 50/50 and put in as the coolant levels were low.... could this be doing it? Also, it has an intake system that looks to be a K&M, I replaced the filter on it for a new cone filter and replaced the other filter (not sure what it was, but it was right next to the intake filter) as the old ones were really dirty. I did replace them with the right size filters, identical to the ones it had in. Could the filter change be causing the overheat? I have gotten some really strong suggestions to include coolant, thermostat and water pump. I feel as though the fans turning on cancel out the thermostat, the coolant (as long as what i used isnt bad) shouldn't be the issue because there is no leaks and although it goes down a very very small amount it doesnt go down fast enough for the car to overheat before i notice it. It seems the engine gets really hot, even just by standing in front of the hood, even for a turbo. Can it be that the turbo boost is set to a psi that is too high? If so, what is the recommended level? Any suggestions or recommendations greatly appreciated and welcomed. Also, I can take pictures if need be.