I used the fan this morning (I usually use the AC) and noticed it was blowing wet, sticky air. Yesterday I got the 'low coolant level' message.

The passenger side carpet is dry. The heater core was replaced six months ago.

How is coolant or water getting into the vent system? Where is it coming from?

Thanks, Mike

 

You have a cabin air filter, a lot of times it lets water in. I would start with checking that air filter to make sure it is in place properly, and not a moldy mess.

 

I've also seen on very humid days, a cold AC will blow out moist air. Seen it firsthand on a Hyundai. Definitely look into the cabin air filter too, like Chibi said.

 

It was humid yesterday. Which is rare in San Diego. That might explain the air but why the low coolant level? The car is in the shop today. No coolant leak to be found. Where is my coolant going?!

 

not a expert, but have you had it checked for intake leak?
While researching top swapping I saw videos of tons of 3800 with coolant going where it doesn't belong.
I need to figure out where my oil is going. Just before each oil change get light and is not even on the dip stick. Only known leak is oil pan gasket and it gets done on Thursday

 

Could be a cracked plastic heater/coolant bypass elbow. The two elbows are fairly near the cabin air filter and when they leak they often spray a fine mist into the engine compartment that could be drawn in through the cabin air filter air intake. Those leaks usually don't show up on the ground under the car since they're so fine and don't leak unless the car is running. It's a very common problem. If that's the problem replace them with the aluminum ones made by Dorman, found at any auto parts store.

Here's a how to video:

 

Those plastic elbows are very bad, most break when trying to remove
I made sure to get aluminum during intake repair

 

Well the car is back from the shop. I had the plastic coolant elbows replaced with metal, the electric coolant fan switch replaced, the thermostat replaced, a new coolant level sensor replaced, and new fluid. $400.

After the mechanic changed the other things and filled up the coolant, the light was still on. That's when he replaced the sensor. It was probably just a bad sensor all along. I wanted to replace the elbows and thermostats need to be replaced from time to time but $400? grrrrrrrr

 

I never noticed you having an issue with the low coolant light. Usually it is just a gummed up sensor.

I honestly just unplugged mine, and check level the old fashioned way.

Did you ever get your cabin air filter checked out?

 

Yeah coolant level sensors like to go bad on at least wbodies and trucks