I have a low mile (13.9k) C5Z, so it’s sat a lot during it’s life. There’s a musty, mildewy odor coming from the a/c. Is there anyway to get it cleaned out so the smell goes away or isn’t as bad?

 

Maybe take it to a detail shop. They might have a steam wand or whatever they can stick into the vents.

 

Moved to C5 Tech. Do a search on A//C odors - I have seen some threads in the past on this.

 

The car pulls in outside air from an opening under the plastic trim piece under the wipers on the passenger side. The opening is 90 degrees to the car and faces the driver side. You can remove the wipers and the entire panel, or you can work from the driver side and lift the panel up to expose the opening (makes it harder but doable). To fully access the opening, it's best to pull the trim panel. Remove wipers, and remove the plastic retainers by pulling the center section up and pulling them out. You can then spray lysol into the vent and follow it with an AC spray that kills odors and makes it smell fresh (buy them at parts store). Odor-X, AC Pro vent and duct cleaner, etc.

There are also products that you set the AC to recirc and set off a mister inside the car and let it recirc for several minutes. Be sure you get one that is actually antibacterial otherwise you're just using a lot of scent to cover odors and they come back.

I have personally found that treating from the air intake does the best job because it kills bacteria and stuff through more of the system.

 

Thanks, I thought that was the case, but wanted to make sure.

 

Second the Lysol, if you can find it! It worked pretty well on our 2014 Cadillac.

 

I’ve done this with multiple cars with some success, to reduce the musty evaporator odor. In no way am I saying this is as good as use of an Evaporator odor specific product and a professional application. It has worked well for me though. Also, I am assuming the musty smell is from mold or mildew on the evaporator and not mouse related.

Find the opening for the recirc air inlet, set the blower on high, full cold, and spray a full can of Lysol into the recir air inlet. Your car will smell like Lysol for a few days but hopefully, your musty odor will be gone. Also make sure your water drain from the hvac module is open so that condensate does not collect inside the module.

 

The area below the windshield is called the COWL. Its a trough to help drain the water from the windshield and hood. Its also the air entry for the HVAC air box. The actual opening for the HVAC System is on the passengers side but the entire trough is an air duct. On the drivers side, there is a well where the wiper motor lives. The well is drained by THREE RUBBER UTTERS. That well can collect all kinds of organic crap and it will plug up the drains and the stuff in the well rots and stinks.

You can reach in between the fender and power brake booster and reach the utters. Pop them out and see if GUNK and NASTY liquid comes out. If lots of crap comes out, it may be easier to remove the entire plastic cowl cover and scrub out that wiper motor well.

NOTE! If the well drains get fully plugged, that well will fill up with water and destroy the wiper motor!!

There is also one other large drain on the passengers side. Its a LONG BLACK HOSE. Its located behind the battery, DO NOT pull the hose out. Just pop it loose from the cowl and flush it out with the garden hose. That will blast any gunk that is stuck in the hose. All of the drains easily pop in and out of the bottom of the cowl.

Bill

Bill

 

Bill - I was having a brain fart and couldn't get cowl to pop to mind!

 

Thanks everyone! I’ll take a look at it all.

 

Make sure you clean out your system asap . I have a friend who caught a bad lung infection from mildew in car HVAC system.

 

When I bought my car back in June it seemed fine. Until that first really hot day and I needed AC... then I could practically smell every cigarette the previous owner(s) had ever had.
I bought this:
https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

Like a bug bomb, but in your car. Start the car, close everything up, start the A/C full blast and pop the can. Let it run for 20 minutes... ALL of the smoke smell is completely gone. It has the "New Car" smell...which isn't really new car. But its better than stale decade old smoke.
Hope this helps!

 

i had the same problem...I also had low air flow coming from vents. I ddeiced to replace my hvac blower motor 25min job. When I removed the blower motor I found a rodent had been making a nest in there...it was full of fur leaves and nesting stuff.after I replaced it with the new fan no smell. Hope this helps. Old and new blower

See below

 

The Cowl Cover is the plastic surround cover at the base of the windshield The wiper arm stems stick through it. You have to take the wiper arms off to remove it. Then you have to remove a few push pin reusable plastic rivets. Once you remove the cover you will see the cowl trough and the wiper motor well.

That's the FIRST place to start for smells. If you could have seen the tree bloom stem litter that came out of mine, you would have gagged! It never got to the point of rotting and stinking but it was close.

Yes, you can get a mouse nest in the fan wheel. Been there done that,, That's a whole different PISSY Mouse smell.

The AC condenser inside the HVAC Air Box can get some mold growth on the condenser fins in some climate conditions but, I find that rare. Yep, they make a spray/fogger for that very issue. Most of the time, the bad smell is coming from crap in the cowl wiper drain area on the drivers side. If you change the air circulation mode from taking air from the outside air to the recirculation mode and still have the smell, its coming from inside the HVAC Air Box.

NOTE! If you are new to C5, Our C5s DO NOT have any sort of HVAC Inlet Air Filters. The C6 does but, our C5s DO NOT.

Bill

Bill

 

 

Thanks for all of the info. I sprayed Lysol into the intake under the cowl yesterday, so I'll see how that does. I figured I'd start with the easiest and cheapest, and move up from there. The drain udders all looked good and there wasn't any other junk under the cowl.

My a/c died this weekend, so I ended up changed the blower motor and the control module. While I was in there, I found a little mouse nest debris, so I'm sure that contributed to the odor too. I cleaned it all up real good and sprayed some Lysol in the too.

This forum is great, years and years of experience with these cars. You can get an answer to just about anything!!