some don't like it hot

August 21, 2007 6:41 AM

For about a week, I've noticed a "hot" smell coming from my engine. I don't know how to describe it except that it smells like an iron that has been left on. What is it?

I get this smell even when I drive the short (less than 5 minutes) distance between home and work. I don't notice it when I am driving, but it's obvious once I step out of the car.

I drive a 1998 Camry, 175K miles, oil last changed in May, just passed NC state inspection three weeks ago. I know nothing about cars except to check the oil gauge, which I did, and it indicated there was enough oil. Is the smell indicating something serious ($$$) or just something simple that I am overreacting about because I am automobile-ignorant?

posted by kidsleepy to Travel & Transportation (13 answers total)

If you notice it when you step out of the car it may be something having to do with your wheels or brakes. Are you sure it's coming from your engine? Have you opened the hood to see if you see smoke or can localize the smell? Have you checked your temperature gauge to make sure your car isn't running hot? Do you have enough coolant in your radiator [do NOT open the radiator when the engine is hot]? Also, I'm not sure if by "oil gauge" you mean the indicator on your dashboard or if you mean really checking the oil. If so, the oil gauge on your dash is an oil pressure gauge and you have to actually go under the hood and check the oil using the dipstick. The manual will explain how to do this and it's something totally doable by the average person with a rag.

I smell something like this when I've recently driven through water or when I park on grass and the smell is usually something do do with whatever it is burning off the bottom of my exhaust [which runs under the bottom of your car and is often very hot]. If the smell is obvious you may be able to take it in to a mechanic and ask that exact same question, but I'd check the above stuff first.
posted by jessamyn at 6:51 AM on August 21, 2007

Check your radiator.
posted by konolia at 6:53 AM on August 21, 2007

Response by poster: by oil gauge, i meant the dipstick. i've also been watching the temperature indicator on the dashboard like a hawk, and so far it's been normal.

i'm not 100% sure it's coming from my engine, but it's at least coming from the front of the car. my car is parked outside all the time, and it hasn't rained recently.
posted by kidsleepy at 7:03 AM on August 21, 2007

Well, it's about time for an oil change now anyway. While it's in there, have them check the cooling fluid levels.
posted by jerseygirl at 7:03 AM on August 21, 2007

The "hot" smell that we usually associate with a hot iron comes from the polymer coating on the bottom of the iron oxidizing, as well as any plastic and fabric softeners that have coated themselves onto the iron in the meantime. When I had this kind of smell coming from my car, I'd hit a plastic grocery bag on my way to work and it was sloooooooooooowly melting off of where it'd stuck to my exhaust. Have you looked under your car recently?

Not a bad thing to do in any case, to see if you see something dripping. (Although obviously, the A/C condensation will be dripping from your car.)
posted by SpecialK at 7:17 AM on August 21, 2007

FWIW, I immediately thought of the smell of steam. Check the radiator level.
posted by aeschenkarnos at 7:59 AM on August 21, 2007

If the hot smell has a metalic edge, it is engine coolant. The most common source of this smell in the cabin is a heater core leak.
posted by Raybun at 8:25 AM on August 21, 2007

FWIW, I immediately thought of the smell of steam. Check the radiator level.

I'm not going to say anything for certain since I haven't looked at the car -- definitely check the radiator, kidsleepy -- but you usually get a very sweet smell from steaming radiator fluid because of the ... dang, what's the chemical, ethelyne glycol?
posted by SpecialK at 8:27 AM on August 21, 2007

You might check and make sure your brakes are working correctly as well. If a brake pad is hung up, or the caliper is stuck, it will stink after even a short trip.

If it goes on long enough, the brake can catch fire. This type of brake failure usually happens on high mileage cars, because the pins that that the caliper slides on become corroded, or some other part fails.

It's easy enough to do an inspection, and pretty easy to fix. If you don't know what to look for, any reputable garage can do a quick look in less time than it took me to type this.

Hope this helps.
posted by Pogo_Fuzzybutt at 8:29 AM on August 21, 2007

I suspect that with this many miles, your engine is starting to leak a little oil out on to hot surfaces, such as your exhaust manifold.

For instance, your valve cover could be weeping just enough oil to create that hot smell, but it would take a long time before enough oil was lost to actually register on the dipstick.

Another thing that makes a nasty smell is when the rubber jacket surrounding your CV joints (the flexible axles that actually transmit power from your Camry's engine to the wheels) begins to deteriorate and leak, which causes really gross-smelling grease to be flung around the engine compartment, where it could be landing on hot parts and sizzling.

I'd have it looked at by a mechanic. If it's just a little oil leak, you could let it go for a while as long as you kept checking the oil.
posted by M.C. Lo-Carb! at 8:46 AM on August 21, 2007

radiator - I've ignored that smell before. It never goes away and left me on the BQE more than once! (I've had ever beater from Volare to a Geo Prism)
posted by any major dude at 9:28 AM on August 21, 2007

In addition to the radiator, there is a heater coil that has engine coolant running through it. When this leaks it is more likely to be smelled inside the car than out and may not be visible from outside. A check of the cooling system should definitely be on your to do list.
posted by tommasz at 9:41 AM on August 21, 2007

Last time I had this problem a plastic bag had blown under the car and partially melted onto my exhaust line. I scraped as much as I could off and it went away eventually. Okay, it's kind of a long shot but easy to check.
posted by nanojath at 10:45 AM on August 21, 2007