RAY: Well, these are classic symptoms of a leaking heater core, Judy. But your car seems to be too new to have a bad heater core.
The heater core is a second, small radiator that provides heat to the passenger compartment. When you call for heat, coolant from the engine circulates through it, then the fan blows over the heater core and transmits heat from that hot coolant, through the vents, to the car’s interior.
But if the heater core is leaking, coolant mist can get blown by the fan, along with the warm air. Coolant is greasy, and guess what it does? It leaves a film.
It also has a sweet taste, but it’s toxic, so I don’t recommend that you give it the taste test. You might want to give it a sniff, though, and see if it smells at all sweet to you.
If you were writing to me about a 2005 Yukon, I’d feel pretty certain that a heater core is what you need. But it’s odd to have one fail on a newer car.
The only other possibility is that the vinyl from the car’s dashboard and interior parts is outgassing. That’s what most of us know as the “new car smell.” But it’s actually the sublimation of vinyl particles into the air, which can leave a film on your windshield, too.
But you say the film appears every time you use the defroster, so I’d have to lean toward a heater core problem. You’re probably still under warranty, Judy, so go back and ask them to fix it. If they say, “It’s related to the defroster,” ask them how. The only way I can think of is that the heater core is leaking coolant, and it’s blowing onto your windshield.
If they have another explanation, write back and let me know what it is. Maybe we can use it to get rid of some of our troublesome customers. Good luck, Judy.
Lying gas gauge probably due to bad sending unit
Dear Car Talk:
My wife, Mary, has a 2010 Chevy Cobalt. Recently, she noticed that the fuel gauge indicated more gas than there could have been in the tank. The following week, she took the car to the local dealer. After more than an hour, Mary was given an explanation that she didn't understand: She was instructed to keep the tank full, and told that the problem might resolve itself. Until this situation arose, the service people had always been very helpful. Mary returned home disheartened, and with an inaccurate fuel gauge. There was no charge for the "help." Any suggestions? – James
RAY: Well, that was nice of them not to charge her. But the advice she got was worth exactly what she paid for it.
It sounds like she’s got a bad sending unit. There’s a sensor in the tank that floats up and down along with the level of gasoline. It sends a signal to the fuel gauge, telling the gauge what position it’s in, and therefore how much fuel is in the tank. It sounds like Mary’s sending unit no longer works.
Maybe the dealer thinks the float is stuck, and by filling the tank frequently, Mary might somehow help unstick it. We sometimes do see sending units that fail on and off for a bit when they’re on their last legs. But eventually they always seem to conk out completely. So if she gets relief, my guess is it probably won’t be long-lived.
Unfortunately, making that repair involves a fair amount of labor, because it requires removing the gas tank.
But unless she’s comfortable keeping track of her mileage, filling the tank based on how many miles she’s driven, always driving with a fully charged cellphone and never lending the car to anybody, she probably should get it fixed.
I’d suggest that you go back, James, and ask for a more detailed diagnosis. If they’re sure it’s the sending unit, and Mary plans to keep the car for a while, it’s probably worth spending a few hundred bucks to fix it.
About the Author