Musty smell when AC is on

I can't take the musty smell coming from my dash on my '96 anymore and was wondering if anyone has had/solved this issue with the Riv? Also, it appears that my passenger side is taking on water again when I removed the rear seat and pulled the carpet in front of the battery I can see wetness. I thought I fixed it a few years when I siliconed around the drain tube up front. Is there a way to blow/clean the evap case out?


Thanks

Theres actually a gas you can charge into your system to remove and kill the mold thats building up in your system....

Link

just google it....theres a bunch of stuff out there

Wow, for $850 bucks I want all the ductwork pulled and replaced with new!

Jack the R wrote:

Wow, for $850 bucks I want all the ductwork pulled and replaced with new!

its a riviera it cant be that cheap lmao. i have love for the riv, just not the cost to replace things

I had a 03 Jeep Grand Cherokee. Had the a nasty musty smell it's the Evaporator in the dash not sure how to or cost on the Riv the Jeep was $1000 done at the dealership,

I tried to get at the evap and holy s@#$ forget it. I pulled almost every panel off under the dash and there is no way to get at it unless you pull the entire dash apart. It helps to be flexible as well, damm it's crammed under that dash! I was able to see up in there after I pulled the blower fan, and blower resistor out. The evap is caked with dust/mud so I'm screwed. I pushed a pipe cleaner brush into the drain and nothing really came out so I'm not sure if it's plugged somwhere internally. Not to self "never by a car that has been driven exclusivley on gravel roads". All the duct work and everything else under there is coated with gravel dust.

If my experience is any indicator you all need to chil, this is easily fixed.

I have had the same problem twice, happens every time I park outside when there is a lot of pollen or dust in the air. This "fix" will last, in my experience, at least a year.

Here it is step by step.

1) Get a gallon bottle of Odo-Ban (Sam's Club) - if you are not member of Sam's just ask for a day pass at the customer service desk, there will be a small charge if they are not running promotion. Sometimes day pass is free.

2) At home, mix a cup of the odo-ban with a pail (2 gallon max) of hot tap water. Stir to mix

3) Make sure the A/C drain is open - then Pour the pail of solution into the air vent in the cowling - It is under the wipers, has what looks like window screen - as follows: Pour about 1/2 gallon in to start and make sure it all runs out. If you need to, clear the drains. Then pour the rest in. Let the car sit overnite. Odor gone tomorrow, most likely.

If odor is not gone, repeat next day but add 1/2 cup of household bleach to the water/odo-ban mix.

4) If you have a spray bottle mix a deodorizing solution per the odo-ban bottle and while the heater is on with fan on full, spray some solution into the cowling air intake. Switch the a/c full on (not max/recirc) and do it again. Idea is to put the aerosol in so it hits the musty smelling stuff in the HVAC and neutralizes it.

Again, let sit overnite.

It will take a couple days for the odoban/bleach smell to taper off. If you have to drive turn on the a/c or heat and open the sunroof to vent position or crack a window.

Albertj

Albertj , you are so useful!

i agree tony

When you say let it drain what are you talking about? If you pour this into where you say won't the blower fan get drenched?

Well, 96RIVMANN, that's why you pour in about 1/2 gallon first, about what you might see parked outside in a torrential rain, and See If It Drains out the AC drain under the hood. . If it does not drain don't pour more in.

It also occurres to me that if the evap is caked with dust as you describe, might be a flood car. Easy way to tell is to check other body cavities like under carpet or inside behind the door panels, mud there means it probably was flooded at one time and not fully cleaned up. In which case, make more of the odo-ban solution...

And if you are pretty sure you have flood mud, you might want to clean it up with HIBICLENS. You can get it by asking a pharmacist to order for you. It Is Expensive for what it is (a surgical sterilization scrub) so first you clean off the dirt you can see then clean again with Hibiclens. I cleaned out a car using that stuff once, I needed about a quart of it. You can get it on EBay for about $15 a quart, or about $55 a gallon, plus shipping. Get it locally if you can, because shipping a quart of the stuff should run you $9 to $15...

By the way Hibiclens gets rid of odors by killing the yeasts, germs, bacteria that cause them. It will leave the HVAC smelling kind of like a hospital for some days. Odo-ban gets rid of odors by a combination of natural oils (eucalyptus and I think peppermint, both of which are effective anti-infectives but don't work instantly) and enzymes (which digest/liquify some of the organic matter, and don't work instantly either). It will leave the HVAC smelling like Odo-ban for some days. Advantage of Odo-ban is that the organic matter gets digested then the enzymes die. With Hibiclens the germs get killed but the organics stay, and when fresh germs land (soes not take long) with a little moisture eventually it wil stink again.

What I wonder is if we could remove the plastic cowling and then use a pressure washer (or hose and brush) to clean off the evaporator and heater coils? I have no idea but it would be swell if it could be done.

Bottom line is you have to determine if that HVAC airbox is draining right (and not draining into passenger compartment) before you dump a couple gallons of this Odo-ban soup into it. Good catch.

Albertj

I bought the car from the original owner and know for a fact that it's not flood related. I had the same problem several years back and found out that it was the AC drain tube. The water would run out the tube and roll back into the car because the gasket aound the tube was dry rotted. I siliconed it up and it was fine for about 4 years now. I did notice that the capert is wet again behind the passenger side rear seat. Looks like I will be pulling the seats, center counsel, and carpet this weekend again to air it all out. The last time I did this there was at least 1.5 gallons of water that had soaked up into the carpet foam. Since I see others have the same problem I guess you could call it a design flaw by GM.

96RIVMANN: In principle I agree with you, looking at the placement of the drain, they could have done better but it would have cost a little more. I still wonder if we could remove the plastic cowling and then use a pressure washer (or hose and brush) to clean off the evaporator and heater coils - I have no idea but it would be swell if it could be done. I'd stick a wet-dry vac hose into the box to suck out the mud that busted loose from pressure washer.

I am sorry that the silicone let go of whatever it was gasketed to - what a bummer. Maybe you want to use "Goop" instead of straight silicone this time; Goop has a solvent in it that 'bites' most surfaces somewhat better than the straight silicone will.

I had to do this once with a car I used to own. It took a while. And - instructions come with the Odo-ban to make a deodorizing spray - you could spray the carpet and pad once you pull them to get them dry.

I hope all this helps somehow, and good luck

Albertj

I pulled the front plastic valance this morning (what a PITA) and broke all those stupid plastic screw/retaining clips. There is nothing really under there. albertj, your idea of pouring a 1/2 gallon of water/odoban would do no good what so ever. There are two drain holes at each side of the car if you look up under the front wheel well covered by a rubber flapper. If you were to pour water in it would just run right out there. I think what I am going to do is remove the blower resistor and run the fan and spray some type of mold/mildew killer solution while the fan is running.

Thinking about it, I think the odo-ban solution worked for my kind of problem-I've done it twice. This should clarify: My Riv is garaged most of the time. Sometimes it gets parked outside under trees. In the spring the trees have a lot of pollen and it makes the air intake stink so that my car's not really drivable with windows closed.

Flushing the area you showed gets rid of accumulated pollen.

That said, it is good that you were able to determine that my solution would not work for your problem - I was emphatic about it because it worked so well for me - but just because I am emphatic does not mean I am correct. I wish you well solving your problem, and hope my postings helped even if I was sincerely wrong about this one. If nothing else, you were motivated to do the work to prove the cause/prove me wrong, and did not stop with your first question. As for those clips, I don't take the cowl cover off for this. When I have removed it I've used a trim tool from CarQuest. I can't get to it this minute so can't tell you who makes it. It was about $15.00 when I bought about 8 years ago.

And for those whose HVAC odor cause is similar to what mine was (an accumulation of rotting organic particles in bottom of air intake box) this works much better than the deodorizer the dealer sprays into the ducts, as long as the drains are open and do not have broken seals. Particles have to be small to get past the screen in the cowling, and should either flush out or be able to be de-natured (the odo-ban, bleach, Hibiclens thing).

Albertj

albertj-thanks for posting all the info you do. It helps me to learn about the Riv.

Bert:tavis:

Pulled the passenger seat and lifted the carpet on that side only to find out it's only the rear carpet behind the seat that is wet. I can't see where it would be coming in! Anyone else have any ideas?

Did you pull the rear seat yet to eliminate that as source?

Might be coming in past the passenger door weatherstripping - close up the pass. side and have a buddy pour water on around the windows and door on that side with a hose while you sit inside and try to find leak.

Or close a strip of copy paper in the door (in the weatherstrip not the latch) and see if it pulls out too easy.

I pulled the passenger seat lifted up the carpet and confirmed that it was not the ac drain up front like it was before. I really can't see where it could be coming in other than the small rear window. I't been dry for a awhile so I am at a loss. I can't seem to figure this one out.

My guess would be door weatherstrips. If you use an automatic car wash, or a pressure washer, or even a strong garden hose it is not unusual for the water jets to force water past the door/window weatherstrips. The water runs down the strip and puddles in the rear footwells.

Unless somebody spilled some water back there and did not tell you (after allit's only water...)

When you pulled up the carpet did you find water stains or clinging insulaton near the rear quarter panel? Maybe the water's coming for the wheel well? just a guess...

...or (weak joke coming) maybe a passenger had an accident riding with you the last time you did 75 mph off that freeway exit with the hairpin turn at the end (JK)?

Again you pulled the *passenger* seat. I'm asking did you pull the back seat? (actually, I pull mine once a year anyway to check the battery for corrosion/leaks). There is probably no problem, but if there is a problem the sooner you find out the better off you are.

Albertj

Yes, I pulled the passenger seat and the rear seat.

I'm out of ideas. If I were you I'd check the door weatherstrip.

Albertj

Last night I sprayed water from the outside spigot into the AC evap drain on the firewall 3 times and now it seems to drain very well. I think that it just must have been dirty inside the hvac/evap case not letting the ac condensate to drian. Hopefully this will take care of any further musty spells? I still need to buy a can of the odor gone spray, remove the heater control module and blast away at the evap coil.

you could use a garden sprayer to squirt an 'odo-ban' solution into the evap drain. The enzymes in odo-ban will process the organic matter causing the smell.

Albertj