Yes, I admit it. I'm sensitive to burning/heating smells. I thought that if I bought new, the chance of having that would be lessened. Looks like it's a lot more prevalent than I hoped. The car is less than 3000km, and I am already quite bothered by it. I say burning/heating because it's not like it smells like smoke, but it sure smells like something -- like what a heater might smell like if it hasn't been turned on for some time. But it smells like that every day.

Googling says it might be a plastic bag caught under the car, but no, it isn't. Besides, it's just when the heater is turned up. I'm not sure how fumes from a heated plastic bag would make it up to the intake vents at the front, especially when the car is in motion. More googling says it's the catalytic converter, but same questions apply.

I'm beginning to think that this is just how heated plastic/carpeting/moulding smells, and there is no way to avoid it. If it originates at the heater inside the passenger compartment, filtration wouldn't help (and HEPA filters don't stop smoke, so they probably won't stop scents from heated materials). It does cause breathing problems for quite some time afterward, though I'm sure that depends on individual physiology. While I do get some aggravation with a few rented cars, I get the vague impression that it has to do with the expense of the car. The Fit is considered a cheaper car (was were Tercels in my past).

Do the generalizations in that last paragraph seem reasonable? I may not be able to get rid of the problem without incurring the steep drop in value of a new car, but at least I should understand the likely sources of the problem.

 

The Fit probably emits less odors (odours?) than other cars simply because there is less of it.

The heater uses engine coolant that is about 190-210F to heat the cabin by means of a small radiator (heater core) the air passes across. This doesn't get hot enough to burn. Outside air enters via the cowling below the windshield, the area least likely to pick up smells. Try running it on outside "fresh" air rather than recirculate (if that's how you have it set).

That said, new cars are more odoriferous than cars that have been around the block a few times. New plastics and vinyls are outgassing. Anti-corrosives are burning off the exhaust. It's that "new car" smell that people rave about. Give it a few months.

Get someone else's opinion. The dealer will be glad to give it a sniff, but you'll probably want a nose you trust.

 

"odoriferous". I like that word

Yes I have it on ventilate. It's winter and windows fog up on recirculate. I'll certainly ask for someone else's opinion, but the scent is not subtle.

The new car smell is now gone (I think), and the current scent is just something heating when the heater is on.

Thanks for your perspective.

 

Since you are extra sensitive to the smell it may be something others don't notice. On the other hand you say it is still quite strong, so I think someone else would.

If you're willing to take a look on your own you should start with the cabin filter. I'm sure there are threads here for how to access it on the 2nd gen cars; on my 1st gen car it is a relatively simple matter of glovebox removal. But since you're still under warranty you may want the get the dealer to do it.

 

Another possibility may be that you're smelling something in the air from outside the car that the heater is just blowing into the car cabin. For example, lots of people around here heat their homes partly or entirely with wood stoves, and in certain wind and atmospheric conditions their smoke can be rather noticeable inside the car when driving around—and that's for someone who wouldn't claim to be unusually sensitive to such odors.

 

You've probably never changed your cabin air filter. I suspect that dust, pollen and other particles might get trapped in there and then get heated causing the displeasing smell. I recommend replacing your cabin air filter with a fram one. The OEM filter is a little more than 30$ in Canada and the fram is about 20 and comes in an arm and hammer baking soda odour guard variety.

Try changing it, you might be surprised in the amount of crud that gets stuck in there. Change it yourself, it's easy, you just have to unlatch the glovebox. I'm sure there's a YouTube video on how to do that.

 

 

Does it smell if the fan is on FULL speed? The next time you use the fan go immediately to the maximum speed and see what happens.

If the answer is "no", then you probably are smelling the fan resistor getting hot. I haven't looked at the Fit set up, but almost every car puts the resistor for the fan circuit in the air flow path for cooling. That resistor will generate the most heat and smell on position 3 and to a lesser extent in 2 or 1.

It is the coating on the resistor getting hot. I have never removed one in a Fit but usually it is only a plug and 2 screws to get it out. I am looking at a picture of one on rockauto.com. And it has a square plug and has 2 screw holes. A new aftermarket one is $19.15 from them. I would not replace it with a Honda one as you will be starting all over again trying to burn off the coating. This one says it is ceramic.

Here is a picture of the resistor. I haven't looked up where it is located. It is under the dash somewhere and probably close to the heater fan mounted on the air duct:

http://www.rockauto.com/catalog/more...924&cc=3015271

 

Good point. I dismissed this as he said "heater only" but it may be it's more noticeable now.

Still, his is under warranty. I'd have someone else have a sniff and take it in to the dealer if it smells like smoldering electrics. Not to worry, Tommy, the things are designed to burn out. If it does the heater/AC fan will only work on high speed.

 

I have heard of this happening before. It happens primarily when someone installs a new resistor. Usually changing brands of resistor assembly takes care of the problem. I looked at the Honda maintenance manual and I see it mounted on the side of the heater / AC box. I can not tell from the diagram if it is on the front or back side.

It could also be a fan motor overheating. In that case the smell would come from under the dash and not through heat vents unless recirculate is on.

I'm still waiting to see if he tried it on full speed only. If there is still a smell, then the resistor is not the problem because the resistor is not used on the full speed mode.

 

Sorry for the delayed response. It's been a crazy week. I've kept an eye on the thread but just haven't had the time to sit down at a keyboard and respond properly.

@wdb: I should clarify that the smell doesn't bother me, it's the respiratory aggravation. I don't think my nose is more sensitive to smells than others, so I'm sure they would notice. However, they might not notice any respiratory aggravation as a result until they've been exposed to it routinely. It would also probably be more noticable to those with a regular exercise regimen with prolonged exertion, and the effect is likely amplified in regions with bitterly cold climates (even if you exercise indoors). Since the smell seems to be the result of using the heater, I'm not sure if the cabin filter should be the prime suspect, and from brief internet research, HEPA filters do not block smoke (so they probably won't block outgassing from heated materials). I appreciate the ideas, though.

@DrewE: Yes, that's what my internet research suggested (bag caught under vehicle, catalytic converter). However, this should not enter the intake when the car is in motion, and even large-area fumes like smoke from heated homes would not be present in highway driving and highly correlated with the use of the heater. I would also notice the large-area fumes when I'm outside the car.

@MTLan: The car is less than 2 months old, so it's not likely to be the cabin filter. Besides, it is only happens when the heater is used, which is inside the passenger cabin. However, I appreciate the video. It will definitely come in handy one day!

@n9cv: that might be the problem. I just tried it yesterday. Almost no problem when the fan is on full (man, it's loud). And the perplexing thing is that after booting around town on errands for a few hours, I got tired of the noise (and the sweltering heat) and turned the fan down to 2 from 4. No noticable smell! Very odd because it makes it even more puzzling to conclude that the resistor is the problem. Though starting and running with the fan on 4 for a while seems to have a noticable effect. I think more testing (with me as a guineau pig) is needed to discern a rough pattern, even if it's not 100% repeatable. About overheating fan motor, the smell occurs (before yesterday, that is) when the fan is on 2, so it's not going all that fast. Whether the smell is coming from the dash or heating vents, I can't really tell, but it is correlated with heater usage rather than fan usage.

Thanks for all your thoughts and idea, guys. I will keep an eye on this resistor business.

 

Your experience from yesterday running on 4 and then 2 puts my fan resistor suggestion in doubt. Keep playing with it and see if it is fan speed oriented.

Could this also be a very small heater core leak? Do you know what hot anti-freeze smells like? Normally heater core leaks cause moisture accumulation on the front, windows. Again I'm just guessing here.

 

hi all .. sorry guts if i am introducing in the wrong forum as i did not get the the right section to do so .. coming fresh here to join the community and hoping i am invited

 

I still think it's the cabin air filter. At least inspect the thing!

 

@n9cv: I screwed up the courage to run it on 2 continuously today. Near the end of my 35 minute drive, I started to get continuous heat/burn smell. So I think it has to run more than half an hour continuously before the smell starts when the fan is on 2. I will keep trying to extablish the pattern.

But if it *is* the resistor, and if this is commonplace, i wonder what changing it will do. Unless, of course, there is less than 50% chance of getting a bad resistor.

@MTLian: I just spent 42 hours awake finishing a report, and that's on the tail of weeks of extra-ordinarily long days, plus some of the weekends. I have to be picky about the kind of things I investigate with my time (when I have any). It's a new car, and I've described the reasons why the cabin filter is an unlikely candidate. I like to be open minded, so if you could speak to those reasons, I'd be happy to reconsider.

 

Hey man, do what you want but you are complaining about the quality of the air yet you don't think it's worth taking about 10 minutes of your time to drop the glovebox and check the filter the air passes through. I don't get it.

Best case scenario, you look at it and notice its dirty or has a leaf stuck in it or something random and you shake it out or replace it and your problem is solved. Maybe even some grease got spilled on it and it smells when hot air passes thought it? Worse case scenario, the filter is perfectly clean and properly installed and you can say with 100% confidence the problem is elsewhere.

If time is of the essence, I'd rather spend that ten minutes to check than to have to take the car back to the dealership and waste half a day on it but hey, do what you want.

I've red on fitfreak that someone put a sheet of fabric softener in with the filter and that has left the car with a pleasant smell. Good luck.

 

The smell goes away. I had that too when I first got it.

 

@MTLian: I think you ignored the part about staying up for 42 hours and also about addressing the reasons for not suspecting the cabin filter. Try the former some time. 10 minutes won't seem like such a small amount of time for anything requiring cognition. P.S. Afternote: I did have time to get back to normal this weekend. In my usual 2-week check of tire pressure & fluids, I examined the filter. It was quite clean, so thank you again for the video.

@xxryu139x: Thanks.