Automotive Forums

I have a new 2006 trailblazer. 3000 miles.  After a weekend vacation, alot of driving, this bad burning oil smell started coming out of the air conditioner.  This smell comes out of the vents, it cycles, every 30 seconds at 55 mph, not at all when I am sitting at a red light until I take off then it dumps a good dose into the vents.  I think the smell is there all of the time but when the fan is on high you can't smell it as much as when the fan is on low.  It makes me nauseous, light headed, throat gets sore.  It is not a mildew/dirty sock smell...I could live with it if that was all it was.  Does a small freon leak in the evaporator coil smell like this or maybe antifreeze.  It has been a month since I started smelling this and my air is still blowing cold.  I have been to the dealership 5 times trying to get someone to tell me what it is and they say all that they smell is that "new" car smell.    Does anyone have any idea what it is.  Any help would be appreciated.  

Is your antifreeze level dropping at all ? Also turn your system to
defrost and see if your windshield fogs up.  

I had the same problem with a brand new Toyota Sequoia- turned out to be a bad catalytic converter. Bad deal was the dealer and factory would NOT warranty it! even though it was brand new.
At over $1200, I decided to sell.
ps- the smell I had reminded me of sulfur, and was most prominent when I was under hard acceleration, such as climbing a hill, or entering a freeway etc etc.

Hope that helps!  

What setting is the HVAC in?(recirc or fresh air) this will tell you if the smell is coming from outside or not....your vehicle takes in air throught the passenger side of the cowl when in the fresh air position.  it is possible to have smells coming from under the hood into the cabin...you might open the hood with vehicle running and see if you can smell what is coming from the vents, if not I would tell your dealer you want the HVAC system cleaned...it is not uncommon to get mold or other things growing in the HVAC system and causing odd smells due to the amount of moisture in the system, they make special cleaners that go through the vents and kill off of these things and make the smells go away....I persoanlly reccomend the BG Frigi-Fresh product

Nick
ASE Master Auto Technician, L1  
ASE Master Auto Technician, L1, ASE Certified Service Consultant, ASE Certified Parts Specialist, Chrysler Certified Service Manager/Technician

I haven't checked to see if I am loosing antifreeze yet, it is on my list thanks  

The setting is on recir.  With the air off and the recir off I don't smell it.I have only had this vehicle 2 months. The thing that tells me that this is not a mildew smell is that it dumps this smell into the vents every 30 seconds.  20 seconds out of 30 there is no smell but air.  

If you are on recirc then the smell is from the inside of the car...go to your local dealer and they make products such as BG that can fix this...if you are not loosing coolant...

Nick
ASE Master Auto Technician, L1  
ASE Master Auto Technician, L1, ASE Certified Service Consultant, ASE Certified Parts Specialist, Chrysler Certified Service Manager/Technician

Sorry guys, I couldn't find where I posted this problem.  All winter I did not smell this chemical odor from the vents. Unless the heated air masked the odor??? I just now took it back to the dealer (again) and insisted they fix it. They did say they smelled something and they found a resister to the fan under the dash that had started to melt the plastic. I was hoping that this was the problem but nope.  I took it for a drive and in about 10 minutes the smell started coming in the vents. At 55 mph with the fan setting on 2 it cycled the bad smell through the vents every 25 seconds. The first 10 minutes all I smelled was the dirty melting ice smell, I assume, when the compressor turns off, then the cold air smell when the compressor turns back on. Then it changed. After the chemical smell started it replaced the dirty ice smell. The dealer does not know where to go now. As far as I know I don't have a problem with my fluid levels. They checked all that. I need help understanding the dynamics of the air system. Even if I have the Recir on there is still outside air coming in. So where could this smell be coming from? What takes 10 minutes to warm up. It is 100 degrees outside and it still takes 10 minutes for the smell to start flowing. Could I be smelling a drip of oil on the hot exhaust pipe or maybe transmission fluid? I don't know what either one of them smell like hot. Please help.  

Ok, I now know what is going on with my 2006 Trailblazer. I have a large freon line running up and over the front of my engine. With the recirculate button on and the snowflake button off going 55mph and having the fan setting on 2 (this setting disperses the most smell)and after 10 min. of driving this freon line frosts over then the compressor kicks off and the line defrosts. The begining of the defrosting is when the smell is in the vents. My air is blowing 19 degrees through the vent with just the recirculate button on, and 29 degrees with just the snowflake button on. My problem is that the air is on when I have the temp setting in the red lines for heat. The freon line is still frosting up when I have the heat blowing through the vents just as hot as I can set it. There is no cold air blowing through the vents but the smell is still there. If you stop the vehicle and prop the accelerator to run at 2000rpms you can watch the line frost up. I WANT TO KNOW IF IT IS NORMAL TO HAVE THE AIR RUNNING AS FAST AND AS HARD AS IT CAN WHEN YOU HAVE THE SETTINGS INSIDE THE CAR ON HEAT? I can't believe that this is the way it is supposed to act(according to the service dept). It seems like my compressor running all the time will wear it out faster and also drop my gas mileage. There is not an adjustment on the switch on the vacuum canister that controls when the compressor kicks on or off. I just want to know how to keep the freon line from getting to the point of frosting over. Thanks