CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Foggy windows

Our 2006 Volkswagen Jetta TDI, with 227,000 miles, recently started to fog up inside everytime we drive it. The dealership cleaned the sunroof drains thinking that was likely the cause (although, the car is always garage parked). That did not resolve the issue. We have to have the defrost on full blast to be able to see out the windows, and still we need to roll back windows down to wipe condensation to see out of them when making a turn. Please help give us ideas what could be going on?

Keep an eye on your coolant levels, I have had and have seen windows fog constantly due to a heater core leaking. It doesn’t take much of a leak to fog up the windows.

Has the air-conditioning system been verified to be working correctly?

i think your car’s heater core is leaking.

I would also check to make sure the drain hole for the evaporator case is open and not clogged. This would prevent any condensate from draining with the air conditioner system being on. Try to make sure the air conditioner is also on when you use defrost to pull any moisture out of the car as well. Your statement said “we” but you didn’t say how many “we” pertains to. Having 4 people in the car can also add lots of moisture to the interior.

Check all your carpets (including the trunk) and see if any are damp, there could be a water leak.

But my first guess is a leaking heater core (especially if there’s a residue on the windows) or your a/c isn’t turning on when you use defrost.

are you leaving it on recirculation? You should be on outside air.

Wow, thank you to everyone who has given us directions to pursue. FYI ususally there are one or two people in the car. My husband is now tackling looking at these leads…

The bros always lick the windshield - If sweet then you got a bad heater core. and if not sweet, odds that you got water leak in the rear door panel.
Tom and Ray were correct 4x on our Jettas. We had both problems on 2 VW;s :frowning: