Horrid chemical smell from defroster vent

Get borescope, drop blower motor, start looking in vents, inside and out. I bet rodent. Once you find it, block over your fresh intake with wire mesh-there are multiple intakes not just the big rectangle one.

 

Might be a good idea to stop smelling and breathing whatever has crapped / pissed / died all over the heating and cooling system.

That can't be good for you.

I despise mice and what they do to vehicles!

 

Tiny update, the shop took a wiff when i brought it in today. They think it smells like burning plastic and wondering if a vent controller/electric motor is fried. They didn’t have time to get it in today to mess with it but they agree the smell doesn’t fit the usual suspects.

so a couple things, I screened the intakes months ago. And the smell only comes after running it for awhile and it goes away… until you shut off the truck. The second you start it back up poof! I can’t imagine that dead mice would stop smelling and then start smelling again randomly… but who knows at this point.

I’ve had died mice in my 50’s VW lol that’s different from this but my truck actually has a heater sooo.

 

Are there more besides the two on the left, under the cowl? I’ve only seen those two spots. The large one and the one in the corner.

 

I sincerely hope it's not rodent related. I love the environment as much as the next, but soy based wiring insulation is a bit extreme. It's a mad world where the Dung Beetle has more importance than human evolution /advancement.

Just crazy!

But again, of all things it may be, I'm hoping it's not rodent related. And the way you describe the occurrence, your right... a corpse is either rotting or its not, and eventually the smell would continue without the blower fan on at all.

Will be very interesting to find out!

 

There's one on the drivers side behind the wiper motor that gets missed sometimes.

 

crap!! I missed that one!!

 

My bet would be a burnt motor smell, actuator, blower motor, something melting plastic......

 

Ok got the truck back from the shop… they gave up and have no clue. It’s not coolant, the pressure test was good. They can smell it and are still stuck between plastic or freon. It’s the newer freon and they can’t test that at this shop so they suggest finding a shop who can test the freon and it that passes look for burnt plastic. I’m going to be busy this weekend but tomorrow ill pull the fan motor and give it a look with my bore tool. Well that wasn’t what I was hoping for but they were very confused as well. Said its unlike anything their nose could recognize. Didn’t charge me either, nice folks

 

A good AC repair shop will have a freon sniffer. May be worth it if you can't find anything poking around.

 

Any news on this ??

 

Sooooo… took the truck to another shop after striking out at the first. This shop has a r1234y@ machine and said they could test the freon levels for $100. They had the truck all day drove it around and said they smelt burnt plastic and felt the heater was actually running too hot. I asked them to check the freon pressure just to make me feel better with my kiddo. They told me that the fancy new freon machine is 100% automated and once hooked up it has to drain and refill the entire system and said it’s not worth it. Also they said that the newer freon systems will stop working if they sense a pressure difference (leaking system) and with the way the ac is working they think it’s not freon. Charged me $75 and said sorry clueless unless I wanted to pay them to tear the dash apart.

I pulled the fan and scoped the heater box. Just a little dusty but I did find a piece of foam that that was like a sponge almost like a prefilter. The foam was about 1”x5” and was sitting next to the evaporator or heater core (whatever one I could see). The foam didn’t have any signs of melting. Other than that it was spotless. There was no oily film in the vents of box just a tinny amount of dust. No signs of mice in the vents or box.

I bought a can of the toyota evaporator cleaner mentioned earlier and soaked the system. The drain was clear and the cleaner came rushing out as expected. Put it all together and blasted the heater.

After I let it all dry out and sit over the weekend I washed the deicer off the undercarriage. Couple days later its all gone and now there is zero smell and i mean zero.

Ultimately I think it had something to do with the deicer and never using the full power of the upper vents. Other than that I have no clue. Multiple people could smell it but not one could tell what the hell it smelled like. Ill have to see what exactly oregon uses for deicer.

Anyway couple days on the road now and the smell seems to be gone.

 

I followed this thread for this long and there was no dead hooker located in a secret compartment!? *ugh!

Glad the smell is gone, even if the outcome wasn't very exciting

 

Glad you got it figured out. If it was just the regular stank from the evaporator, sometimes its best to turn off the A/C- defrost etc. after running it, and before getting home, drive awhile with the re-circ off and let the outside air dry the evaporator to try to prevent it from getting moldy.

 

Dang! Glad you got it fixed, sometimes I think I smell something and it drives me ...But most of times its a matter of "He who smelt it, dealt it"

 

Excellent news! Did you spray the cleaner in the core through the opening after you removed the blower motor like the guy did in the video with the Land Cruiser. Just curious how hard it was because I’m going to clean mine this spring.

 

Yes just like the video. Dropped the blower and snaked through the vent to the core. I used my bore scope to see where the hose was and tried to spray the entire area. Cleaned my scope too at the same time lol

 

Glad to hear you got it sorted out

 

Thanks for the update and on to the next big thing ! Good to know about Toyota branded evap spray..

 

Glad you are rid of the horrible smell. What about the loss of coolant? You added 1/2 gallon then months later added 1/2 gallon more, any clues as to why?

 

not sure, one shop said that an overflow isnt a deadset reading and wasnt concerned. The fact that its only been a gallon over 50000 miles in total wasnt a concern to both shops. It was funny though, while this was going on and I was monitoring closer than normal, the level in the overflow changed by a good amount daily. I didn’t fill it this last time but it actually came back up to acceptable levels. Also the temps around here have fluctuated from the 20’s to 50’s not sure if that matters.

 

Thanks, Temps really do make a difference. I'm in South Dakota and when it is below 0 my overflow tanks get low. Engines take a long time to cool off completely and if parked in a warm garage takes even longer. Possibly since the bad smell started and you did focus on the coolant much more, and noticed the small changes as you said, that's all it is.

 

I’m starting to have this same problem. The stale air, hard to describe, is exactly what I’m getting early in my drive. No real bad chemical or burnt plastic smell. After it’s parked overnight and I get in I keep thinking the kids left some food in the truck by the smell.
I am getting moisture buildup on the windows during my drive with the defrost / feet on warm, and becoming a problem freezing overnight.
I haven’t noticed any coolant loss, though.
Is the heater core an OEM recommended replacement or are aftermarket’s OK

 

It’s sadly funny but the smell is back!! It only happens when the temp outside drops below 30*f. We had a cold snap for about a week and then the smell came back for the first few minutes after startup. Smells like chemicals still. Now that the temp is back into the 40-50s it’s gone. Guess I’ll just move someplace warmer….

 

Almost sounds like something is dripping on a hot surface and burning - probably can’t find it because it burning before it can drip all the way down. Could it be a pinhole leak in one of the lines dripping on a heat shield? Transmission fluid and differential fluid both have bad chemical smells……

 

I had my cabin filter changed and then about a year of so later, I started getting a musty smell after using the heater or a/c. It was around for a while and then went away.

 

I have been having the same problem for 3 months. The dealership kept my car for 3 weeks and tried everything including ozone treatment to the system. After the ozone treatment the smell went away for a couple of weeks then this week I turn on the defroster and the smell is back worse than ever, a chemically smell very strong, only when defroster is on so cannot use the defroster.
Did you ever find out what was causing the smell?

 

Only thing it could be? Sure it's not blower motor but then it would smell all the time. For future reference let us know if you find out.

 

It’s definitely something to do with the a/c as when you use defroster it kicks in a/c and I also get the smell now when I turn on a/c but not when the a/c is off and blower heat is running.
The dealership has been no help, I suggested Freon leak or mould but they said no and also did an ozone treatment but the smell came back after a couple of weeks.
I also thought maybe windshield washer fluid leak into the cowl but they say no. I feel like I’m doing all the leg work, so any ideas would be welcome.

 

Q

Only other thing I can think is bad ac compressor clutch or fan belt but it would squeak.
Does it smell with circulation button on or off?