I have a 2000 GTP with 175K miles and this is my second posting.
My first posting was for “Engine is OFF-CENTER” and you guys very quickly found the correct answer Bad Motor Mount.
Anyway, I now have a new problem.
First, some background:
I had a Low Coolant Level Light.
Because I did not want to deal with the Coolant, I had the Firestone Dealer (the car was in for tires) Flush the Cooling System & replace the Coolant Level Sensor. While they were doing this they said it needed a new Lower Radiator Hose, so I had them replace that too (Boy did I bend over & grab my ankles on that one.).
Ok, great. Shortly after getting the car back my wife mentions that the Coolant Temperature Gauge is running higher that before. When I check the car, I notice that the Gauge is fluctuating Up & Down. After searching the Forum, I decided that the Cooling System needs to be Purged.
Ok, great again, that cures the Gauge fluctuating Up & Down.
Then the Transmission Fluid leak starts. It is coming from the Upper Connection to the Transmission Cooler on the Radiator. Apparently, Firestone disconnected the line to replace the Coolant Level Sensor and did not reconnect it properly. I reconnect the line and return the car to my wife.
When she returns from a trip. The car is dripping Transmission Fluid from the same area. Inspection shows the leak to be in the same area, but it is not the line. So, I remove the line to check the fitting that screws into the radiator, only to find that the fitting is not even finger tight. I do not know why, Firestone would have loosened this fitting. Anyway, I tightened the fitting and reinstalled the line. No more leak.
My wife uses the car all day, no leaks.
The next morning she calls and there is a puddle under the car. When I check the car, the puddle is in the same location. However, the area around the Transmission Cooling Line is clean and dry. I check the puddle and it is not ATF, it is Coolant. I cannot find a leak. I clean up the puddle and send her on her way.
After she returns, I check and I cannot find a leak.
I check 2-hours later, no leak & no puddle.
The next morning, a puddle of coolant in the same location (passenger side, front @ the Radiator).
Any ideas where the Coolant is leaking from?
Or, why it is not leaking while the Cooling System is under Pressure?
Or, why it is leaking hours later?
Originally Posted by Bio248
) leak, therefore had the level sensor been leaking, I think you'd have said so. Likely there was a little corrosion on the outlet of the pump where the hose connects or at the radiator. Both will end up wetting the same area. Although the upper one might also drip straight down as well as running down the hose. 
