Question I have a 2003 Mitsubishi Galant and it is leaking inside the car on the passenger side, do you know what this could be and an estimate of how much you think repair would be?
Answer Hi Andrea,
This is normally an A/C case (that houses the evaporator -- the heat exchanger that removes heat from the passenger compartment) drain that has been clogged by dirt and debris. When the A/C is on, the evaporator 'sweats', so to speak, and draws passenger compartment moisture into the case, where it drains out the hole in the bottom portion, extending into the engine compartment, where it finally hits the ground.
Where does the dirt and debris come from? Usually, from the fresh air vent on the outside, at the base of the windshield. Great place for sticks, leaves, and such to gather, the smaller of which ends up at the bottom of the A/C case. When enough makes it there, it prevents proper draining, and the case can often fill up, and water will come out by other means. Sometimes, the drain has a tube that extends into the engine compartment -- that falls off, allowing the water to travel, on the outside of the tube, back into the passenger compartment.
Also, don't rule out the possibility of other leaks, particularly when it rains. Popular water trails have been traced back to windshields (improperly installed), sunroofs (poor sealing, travels down A or B pillars), and door weatherstrips -- to name a few. If it's not A/C, then you'll have to get the car water-tested, which normally is a .5-1.0 flat-rate hour at the dealer, for a diagnosis.
If it's A/C, many times it can be free. If you're in for a service (oil change, mileage service), while it's up on the rack, the drain can often be cleared with a tool or coathanger. Sometimes, the debris can be so bad that the case needs to come out ($$$), but this is rare. Some shops might try and charge you a slight fee for clearing it, or if there is a Technical Service Bulletin that addresses a particular vehicles' propensity to this condition.
