Car Smells – And Tastes

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What can your car tell you just by the way it smells – or tastes?car smells lead

A lot, actually.

Let’s put on our chef hats and see what’s cooking…

* Car smells like maple syrup – 

Almost always, this is a sign the cooling system’s sprung a leak. The chemicals in engine coolant give off a syrupy sweet smell that’s particularly noticeable when the fluid is hot (as when the engine’s been running for awhile) and dripping onto something even hotter – like an exhaust manifold – and burning off as you drive. If you smell that smell inside the car, check for signs of wetness around the front seat passenger footwell area. The heater core – filled with coolant – is located in this area and may have sprung a leak, which you will want to get fixed ASAP. The leak will only get worse if you don’t get it taken care of – and the engine coolant/water mix will eventually make your car’s interior a soggy, moldy-smelling mess. And probably rust out your floorpans, too.antifreeze leak pic

You’ve probably read or heard that coolant tastes sweet, too. It does –  but don’t taste it yourself to find out. The stuff is extremely toxic. To us – and animals. If you spill any in the garage – and have pets – be sure to mop it up before they lap it up.

* Car smells like rotten eggs – 

That sulfurous smell is not a sign that Satan has taken possession of your Camry. It’s a sign your Camry’s catalytic converter isn’t working as it should. When everything’s right, a modern car’s exhaust ought to smell like … nothing. The mission of modern engine controls is to maintain exactly the right air-fuel ratio at all times; to precisely monitor the chemical composition of the exhaust stream in real time, the car’s computer constantly fine-tuning to optimize the burn. But when something goes awry and the burn is no longer optimal – too much fuel in the air-fuel mix, for instance – the converter gets overwhelmed and issues its canary-in-the-coal-mine cry via that god-awful rotten egg stink.rotten egg pic

If you smell that – especially if you smell more than a slight whiff of it every once in a blue moon – have the car looked at as soon as possible. Because it could be more than a matter of a really foul smell. It could end up being a really big bill. For a new catalytic converter. They are very sensitive things – and fairly easy to damage. If the car runs too rich for too long (perhaps because of faulty oxygen sensors; these are the parts that “sample” the chemical composition of the exhaust and feed the info to the computer, which then adjusts the air-fuel ratio accordingly) the converter’s insides can become fouled with soot to the point that the converter can no longer convert efficiently. And they can’t be fixed. Just replaced. Many new cars have at least two converters. Some have four. Each might cost $200 or more – not counting the install labor.

Don’t ignore that smell.

* Acrid, nauseating smell – clutch pic

This one’s hard to describe, but if you’ve ever smelled it, you’ll recognize it instantly. It is the funeral pyre of your clutch (manual transmission cars). The smell arises – typically – when the clutch is being abused, either on purpose, or by someone who does not know how to drive a manual-equipped car properly. In both cases, the source of the smell is slippage. The clutch is not fully engaged. The driver is either “feathering” the clutch on purpose – to launch the car as forcefully as possible – or the driver is a newbie who is trying not to stall the car by doing what amounts to the same thing. Either way, what’s happening is the clutch is burning itself up. The friction material – which is similar to the material used for brake pads, by the way – is literally being ground away by the spinning flywheel – the thing it (the clutch) is supposed to clamp onto in order to transmit the engine’s power through the transmission to the drive wheels. But when the clutch is not quite engaged – but engaged just enough to slip and generate friction (and heat), the clutch material gets what amounts to rug burn.

A clutch pedal should be in – or out. And in-between as little as possible.

Tip: A quick way to tell whether you’ve killed your clutch is to get the car up to about 30 MPH in top gear and then floor the accelerator. If the engine revs up – but the car does not accelerate – your clutch is likely toast.

* Musty, moldy smell – Mr. T air freshener

Usually, this results from one of two sources.

The first is the worst – because it’s the hardest to fix: Wet carpets/underlay resulting from a leaking windshield, window or similar. First, you’ll have to fix the leak – then you’ll have to fix the carpet. Which often means replacing it. Once mold grabs hold, it’s hard to get rid of it without excising it. Especially because the carpet is usually molded to the floorpans, held in place by seat tracks and so on – and it’s very difficult to dry it out. One trick you can try is to use a hair dryer on wet areas. It’s tedious work – but cheaper and easier than pulling and replacing the rugs.

The second source of that gym locker smell is mold in the AC/heater ducts – and that typically arises from internal condensation and poor drainage. You can buy products to freshen up the smell of the air coming out of the ducts, but the real fix is to deal with the condensation/inadequate drainage issue. If you don’t see a small pool of water underneath the front end of the car after running the AC for awhile on a hot day, then you likely have this problem.

Luckily, the fix is easy – and pretty much free.

You’ll need to locate the AC system’s drain pipe – search online or buy a service manual for your vehicle – and make sure it’s not obstructed.

If it is, clean it out – and that moldy/musty smell should go away within a couple of days.

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  1. Back in the good old days carpet could be removed fairly easily. I have taken the carpet out of many cars and vacuumed it, then laid it out on concrete and scrubbed it well with something mild that wouldn’t hurt it, rinse it well and hang it on the clothes line to dry(clothes line, a device made from pipes formed into a T by saddling one horizontally into a vertical pipe with holes in it to string small cable making sure to weld covers over the ends to not have a big wasp surprise. About a 5′ pipe with equidistant holes and you have four cables that if 30′ long, will hold a great deal of clothes. Spread carpet over all four wires and let it sun dry. Now it looks like brand new carpet and smells even better. Be sure and do the mat under it too.

    For those brought up with clothes lines, MiS, PtB, many others, sun drying your bed clothes is the next best thing to heaven on earth. Hell, sun drying all your clothes is great too and after the clothesline is built, it’s all free energy.

    Every vehicle I have owned but one has always had very nice carpet, new looking even when it was 20 years old. The exception was the Silverado that a friend and I used on constant irrigation duty. I jerked what was left out about 3 years into it’s life and got the fancy rubber padded complete floor cover. It was just as quiet and a water hose cleaned it well.

    Speaking of that irrigation truck, it started stinking like anti-freeze and fogged up the windshield. It was in the cold, wet of winter and I didn’t have time to do anything drastic so I stopped by the parts store and got a big bottle of Bar’s Leak and put it in. I ran the truck for another 20 years, leak free, never had to replace the heater core. But I add Bar’s Leak to new vehicles too and seemingly never have to replace water pumps.

    Another thing about clotheslines; we have days when you take light clothing and stuff made of synthetics like socks and hang a washer load on the line with practically and literally 0 humidity sometimes and a good strong sun. You can sometimes hang it all, go back to the beginning and remove what you hung first because it’s already dry. You rarely see them any more(clotheslines) since it’s not in vogue. If you can manage it, build one where the predominant wind is coming across it to your house. Then put a bit of trellis on one end and plant honeysuckle. Now that’s country life at its finest.

    • I remember reading at one time that clotheslines had been forbidden in some cites in CA (and probably a lot of HOAs as well) because they were tacky looking. But someone w/some sense finally made most of them realize that they were ‘ecologically sound.’ May have been the only time the greenies made sense.

      • PtB, well, they could be made from anything and look like a work of art if you wanted. I extended my uprights a couple feet above the lines with 2 3.8″ upset tubing I bulleted the ends on and made something that kept the ends from pulling together. Well, there’s that other tubing you can do something with as in throwing large things over it. I could add same to the ends and create a “roof” over any or all of it so you can keep the sun off something if you want while using it for other things. West Tx. wind in the heat doesn’t really need the sun to be a dryer. I can use that top part to hang game for butchering.

        My wife gets plumb pissed when I build something and figure out how many ways I can use something.

  2. Another smell that spells trouble: Raw gas. If your car smells like a gas station, and you’re nowhere near a gas station, it could be a leaking fuel tank, fuel line, fuel injection manifold or injector. Such a leak could turn your car into a prop in a Michael Bay movie unless fixed. And if you SEE leaking gas, DON’T DRIVE THE CAR!

    • I once did some basic service for a friend’s family member. The complaint was that the car was “running rough.” Among the routine checks, I pulled the dipstick. Dry. And caked with a brownish-black shellac. Got under the car and removed the drain plug. Nothing came out. But I could see the hole was obscured by something. I used my pen to poke at it. A kind of goo began to dribble out. With lumps in it. I got about a quart or so of this stuff. That was all there was in the crankcase. Apparently, the owner had not checked the oil since they bought the car five years prior.

      And yup – it still ran.

          • Wow, that was the 3.8? My parents had an ’88 that just ran and ran. It was a good car when they traded for a PA and seems it had a 3.8 too. Those were evidently good engines. Anything that would run forever for my parents with no service had to be good.

            I tried forever to let me service their vehicles but they never would. I guess they thought it put me out somehow. Then again, I’d always lecture them every time I had to do some emergency work that wouldn’t have been needed had they just simply let me take care of their autos. Change the coolant? Are you insane? Grease zerks? You must be outta your mind. I’d try to tell them to just let me look them over, do stuff like servicing the battery but no, they had a guy they paid who didn’t know one end from the other. And then it would be in the local shop for bs like plugged up gas filter, stopped up air cleaener, etc. And I couldn’t convince them to run them for a few extra miles to not rot out the exhaust so they were always replacing mufflers and pipes. I’m not sure I’ve ever had a muffler rot out or exhaust pipe either.

            Every time I’d drive them somewhere, like a town a whole 20 miles away, a hose would give it up. Don’t know how many times I had to come replace a hose for them.

    • I’ve repaired a lot of dumb things Mark, but lately a few friends have been bringing me small engines, such as weed whackers, lawnmowers and such, that either won’t start or run rough.

      In the vast majority of cases the fuel was old and stale. One guy hadn’t used his water pump for over a year. Nothing in my memory though is as dumb as that picture – classic.. 🙂

  3. Just be aware that if your catalytic converter goes boom then it’s likely, especially here in Oz, that no matter how old the car, the CAT MUST be replaced with another or the muffler shop faces a $26k fine from the EPA. Yup, that’s green legislation for you.

    That’s why I replaced mine with a $75, straight-through muffler by myself, rather than pay $275AU for just a new CAT all by itself.


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