Where to begin... I have a 2002 Ranger Edge 4WD with the 4.0L V6 engine with 134k miles. I have been losing coolant steadily for the past 8 months to the tune of a quart every 2-3 months. I am measuring this from the coolant overflow bottle. I cannot find any leaks showing where the coolant is going. I smell coolant when in the drivers seat when the engine is warm. I noticed the smell a little bit this past
Chicago winter, but even more so this spring/summer. I looked at the oil dipstick, but see nothing unusual. I looked at the coolant in the radiator and it looked normal with no oil looking residue nor any air bubbles could I see. I pressure tested the coolant system and it did not hold 16lbs for more than a couple minutes and then is started dropping off to about 13lbs. I'm kinda stumped and hope you can suggest some places for me to look so I can figure this out. I'm considering a dye liquid and a uv light to try and figure out where it is going. What else would you suggest? I've read posts on here for the last hour pertaining to a common upper and lower intake gasket leaks, but am not sure if my model year is also known the have this issue. Thanks for any and all your input.

 

Check the carpet on the passenger-side floorboard, It sounds like your heater core to me - especially since you said you can smell it inside the cab.

 

if it were me I'd just put in a can of Bar's leak and that would be the end of that problem.