Strange Smell

I have a 2001 Jeep Cherokee with 145,000 miles. The other day I was forced to hit my brakes hard to avoid an accident. About 5 minutes after, there was a faint smell that was oddly familiar (LOL I know what you’re thinking but NO). It smelled very similar to fresh paint. The next day and ever since after about 5 minutes of driving the smell comes back. Its gradual at first and then noticeably strong but does not continue increasing in intensity. I have smelled everywhere most likely looking like a crazy person to neighbors and passerbys but was able to determine that is it not coming from outside the car or the air system. It is simply emanating from within the car with more potency near the back. The car has no debris so it is not possible that something spilled. This has me completely stumped. The car does have a small leak in the exhaust but that has been the case long before this incident. Any thoughts?

Fix what you know is bad first, the exhaust leak. This can be dangerous.

Could the smell be coolant? Try a sample to test. The sudden stop may have jarred something loose in the heater core.

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The exhaust is just a tiny hole in the muffler that I have been meaning to get to but without a garage, crawling around on rocks in the snow has been a hindrance. The heater core idea is something I will be sure to investigate. I have some extra fluid at home that will try and match to the smell and if it does then I suppose it could be coming in from under the passenger side dash.

Thanks for the input!

You may have a brake pad dragging. That smell may be overheating brake pad material. Hitting the brakes hard can move things into rusty areas that now make the brakes hang on. Drive it until you smell it. Stop and walk around and feel the wheels. If one is noticeably hotter than another, that’s likely the problem. It could require a rebuilt caliper, new (or cleaned) slides or even a new brake hose.

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Does this Jeep have drum brakes in the rear? If it does you may have forced fluid past the seals in one on the wheel cylinders. Can any to check look at the drum from behind it, or pull the drums and see. Another way is watch the brake fluid reservoir, if the level is dropping hourly something is leaking. My suggestion is the pull the drums method, this will tell you for sure and right away. If you are losing brake fluid, that is not a good thing.

Brakes are fine all around. Following Bill’s advice went in search of a leak in the heater core. I did a comparison smell test between what I smell in the car and the smell of anti-freeze but they are different. There are no leaks inside the car but under the hood where the hoses enter the heater core I found some residue. I pulled up on the top hose to get a better look and sure enough, fluid started dripping out. When I set the hose back down it stops leaking so it must be coming out under pressure and when it heats up it must have a very different small from cold anti-freeze. I am not 100% sure but It looks like the hose clamp on the lower heater core’s hose has been rubbing on the upper hose and the jerk forward must have been the last straw to slice the hose clean through. At least I am hoping it is as simple as that and a new hose will solve the problem. Maybe this weekend I can get it replaced. Thank you everyone for your input and I will keep you up to date.

Don’t delay, as coolant vapors are harmful to your health.

If the smell is a sweet smell it could be a coolant leak.

I know this should have nothing to do with braking, but it can happen.
I had a truck where I had to slam on the brakes hard. The engines forward momentum pushed hard enough to
hit the fan shroud which cracked the radiator’s upper hose fitting.

Yosemite

Well, you definitely want to get the coolant leak that you found addressed, and quickly.

But I’m not sure that will solve the problem you originally posted about. I’ve never found coolant to smell like fresh paint - although I suppose my nose could be wrong on that.

I live in central NY and since it is such a small leak and being as cold as it is, I’m confident it can get me from work to the auto parts store and back home (TGIF). Plus, I suppose I could just avoid using the heater until it is fixed as this should prevent fluid from entering the heater core right? The radiator itself is in good shape (replaced it 1.5 years ago) and even though the motor mounts need to be replaced, I don’t think there is enough slack to allow that kind of movement. In my experience in other vehicles, excess movement can be felt inside the vehicle upon breaking and accelerating. As far as the smell goes, I have to agree that they smell very different. However, it is odd that they are happening at the same time so I am inclined to believe that it is related. If I replace the hose and the smell goes away, then that is an interesting note to others about a possible leak I suppose.

Minor coolant leaks can smell a little like fresh paint. It’s often hard to tell if the source is in the engine compartment or inside the cabin, b/c air comes into the cabin from those vents under the windows, so engine compartment odors could get into the cabin that route. If the windows are open, engine compartment odors can get in too.

The problem with all that is that stepping on the brakes wouldn’t usually cause a coolant leak. More likely that would cause an exhaust system leak, something like that. Here’s an idea, it caused the cat heat shield to fall off, and now the cat is heating the floor-pan and burning the carpet. So good idea to check to make sure the cat heat shield remains in place. There’s often other exhaust system heat shields, and so the same comment applies to them all.

Well it looks like it is my heater core that is leaking. I checked everywhere I could and have not been able to identify the source but the smell is always there when I call for heat. To my understanding, this is no easy task so I will be ordering the parts as well as a few extras I may as well address while I am in there and put the job off until late spring when I can tolerate being outside :slight_smile: Thanks to everyone for you input.

Jon

It’s supposed to be over 50°F today here in central NY.