What’s that Smell in my Camper?!?


There are many things about RV living that we hadn’t anticipated and though many of them are just variations of a theme on S&B living, there are some aspects that are totally unique to living in an RV. I’m talking about smells. From the generator to the tanks to refrigerators, transmissions, brakes, animals, old carpet, electrical shorts – the list of smells we’ve had to identify and deal with is far broader spectrum, and a few times, more nauseatingly pungent than when we lived in our sticks and bricks home. And we had two babies then – just sayin’.

Since I’ve had to do so much research in trying to find out what various smells and odors on board our RV could indicate, and also importantly, how to get rid of them, I thought I’d put together a list of all the possible smells you might encounter in a motorhome, and what to do about them. Let me know if I’ve left out any important stinks or information about how to get odors out of an RV in the comments below!

Ammonia Odor in an RV

Dometic Refrigerator Removed Due to Fire Risk - RecallParticularly in an RV with a Dometic or Norcold refrigerator manufactured from April 1997 forward, an odor of ammonia should be taken very seriously. If you cannot identify a source of the ammonia (pet or human waste, decomposing vegetable matter, certain fertilizers or cleaners) smell other than your refrigerator, switch the power control to “Off” and unplug the refrigerator through the outside vent panel on your RV. If you’re not full-timing, also unplug the RV from the electrical power.

Then do some research and/or call your local RV tech to find out if your unit is recalled.  Leaking ammonia is a sign of a failed cooling unit which has been responsible for multiple RV fires and explosions caused by leaks in the system.  Read more about the specific manufacturer recalls of absorption cycle refrigerators at the links below:

Dometic Recall Information: http://www.dometic.com/USA/Support/Dometic-Recall-Information/
Norcold Recall Information: http://www.thetford.com/customer-support/recall-information/

Ammonia smells dissipate quite quickly on their own, so if the smell doesn’t go away after opening windows, you need to locate the source. If you have determined that the smell can’t possibly be the fridge, but your rig is still smelly with an ammonia odor, check for an open or malfunctioning valve on the black tank or on the toilet. Do you have a bedwetter, or an incontinent pet? You might also trace the source of the smell to find that mice or rats have made a nest and are using your insulation or air filter in the engine compartment as a toilet as well as a cozy place to sleep.

Burning Oil


Photo Credit: Jenny Downing

Burning oil is a thick, acrid odor and the smoke can be a bluish grey if coming from the engine or exhaust or a thick black smoke if coming from a quantity of burning oil, like on an oil-soaked rag or an oil can. If you smell burning oil, first identify the source – look for oil on the pavement as a clue to the source. If it’s the engine, check your dipstick and see if you’re low on oil or if your engine is overheating. Also check the transmission and generator for evidence of smoke or overheating.

Burning Rubber Smells

If the smell of burning rubber is coming from the engine compartment, look for hoses that might have come loose and are melting onto the hot engine block, or evidence of belts rubbing on the pulley assembly. If your tires are smelling of burning rubber and feel hot, check for a stuck caliper, brake shoe or pad. Do not drive with a braking system issue – call a tow company, or a mobile repair service.

Electrical Smells – Ozone

Ozone is a pale blue gas with a sharp, pungent smell, reminiscent of chlorine to some. To me, it has an electrical smell – if you’ve ever smelled sparks from an arc-welder, that’s what ozone smells like. It’s also strong in the off-gassing from laser printers or photocopiers. What could the smell of ozone be an indication of in your motorhome? First off, check the circuit breakers to see if any are overheated, or if any fuses or GFCIs have popped. Check for electrical shorts, sparks and/or faulty wiring connections. You could use a thermal imager to determine if you’ve got hot spots inside the walls, ceilings or floors that you may not be able to see on the surface. Water pumps, generators and anything with moving electrical parts should be checked and the source of the ozone odor identified. An electrical smell can be brakes also, so check your rims for excessive heat.

Gasoline, Diesel Fuel or Exhaust Smells

Did you flood the engine on start-up? If so, you’ll get a strong odor of gasoline as it off-gasses into the air – ventilate and evacuate. If you’re driving a diesel pusher like we are, check to make sure that your engine compartment is fully sealed and completely closed to reduce any potential for the exhaust fumes to get into the living spaces. Gasoline exhaust contains carbon monoxide, so be sure to take this odor seriously – always use a CO2 detector on board your RV.

Another source of potential diesel odor is the generator, and in some cases, the diesel burner for an Aquahot or other diesel-fueled heating system.  Issues with the fuel lines or fuel system can contribute to smells entering the passenger compartment – check your fuel lines, filters and hoses – after everyone is out of the vehicle of course. Look for stains from leaks under your vehicle and/or the distinctive clean streak left by gasoline. Make sure your windows are closed if you are running a generator, especially if you are using your ventilation fans. Remember that fuel smells can mean you have a serious fire hazard so do not smoke, and avoid creating sparks. Also be aware that some plastics give off an odor similar to gasoline, so if you’ve eliminated all the scary sources, sniff your plastics and you might find your culprit.

Musty or Dirty Sock Smell

The distinctive musty smell of mildew and mold is hard to miss and its source is generally a leak somewhere unknown that has saturated insulation, wallboard, fabric or stuffing for even a short period of time. Also, check your laundry hamper and closets for damp clothing that might be contributing to a mildew infestation. If you have mold, do not simply apply bleach and believe that you have solved the problem. Mold is not killed by bleach, it is simply not visible – instead, look for products designed to kill the mold and/or mildew. You may actually have to cut out and remove the affected surface and then be vigilant about leaks.

Other Burning Smells

Burning carpet smells can often be traced to brake problems. Make sure to have this checked and fixed by a professional as a brake failure could be deadly. A light, sharp odor of burning toast can mean engine trouble. Do not drive with a smell of burning anything coming from your engine if you want to avoid potentially life-threatening and/or very expensive risks. As mentioned above, brakes can emit a variety of burning smells – if your rims are hot to the touch, suspect your braking system and act accordingly.

Propane Leak – Rotten Eggs, Dead Flesh or Skunk-like Smells

Propane has a strong, intentionally unpleasant odor that is added by the gas company in order to alert you to a leak. The smell is often like rotten eggs, a dead body, or skunk-like. It is recommended that every member of your crew sniff the propane and know what it smells like so that you can quickly identify a leak and react properly. Always use a propane detector and test it weekly.  If you have an propane odor that is stronger the lower you go in your rig, you need to quickly ventilate, evacuate and dial 911.

Rancid Smells

Rancid is defined as a rank, stale odor and it is particularly common in spoiled oils, including the oils present in nuts which have sat around too long. Check your pantries and cabinets and if you cannot identify the source of the smell in any of the usual places (sofa cushions, bowl of snacks left out, etc.), you might look for a stash of nuts or acorns hoarded away by a rodent. Usually, the only way to get rid of a rancid odor is to remove the source of the rancidity and in the case of oils (maybe an oil spill?), use Dawn to remove as much of the oil as possible, dry the area, then lay down some baking soda to help absorb the rest of not only the oil, but the smell.

Rotten Eggs  – Sulfur

Catalytic converters are notorious for putting out the smell of rotten eggs when they are going bad, so check your engine compartment to see if the smell is stronger there. Check for a propane leak – the odorant used can smell like sulphur. If not, refrigerator? Hydrogen sulfide in some water supplies (particularly wells) will contribute to a rotten egg, or sulfur smell. Sewer gasses can produce a sulfur odor and so you should check your tanks and hookups to be sure that there is not a build-up of dangerous gasses. Also, check your plumbing vents to be sure that they are not blocked or otherwise not venting as they should. Some people smell a sulphur like odor from a dead and rotting animal, so check for rodents or other small animals that might have seen better days. Could also be the battery, so check for leaks.

If the smell seems to be originating from outside your RV, check to be sure you aren’t parked near a swamp or marsh – the sulphur smell is produced by the oxygen deprived environment which produces hydrogen sulfide as a gas as part of its healthy process.

Rotting Flesh

I don’t know how a potato manages to unleash the scent of decaying flesh (but this guy does), but that’s as close as I ever want to be to the source of that kind of smell. Rotten potatoes will liquify during the putrefaction process and the stench is unmatched by any other rotting vegetable. The fumes from rotting potatoes is actually quite toxic, so ventilate the area well. Throw away anything that it has touched, sanitize and then deodorize the area with baking soda. FYI: Propane can also have an added odorant that smells like rotting flesh. Is the scent stronger at the floor level? Ventilate, evacuate and dial 911.


Did you, perhaps, hit a skunk? You’ll most likely know it quickly if you did. The smell of a skunk’s spray is due to methyl mercaptans in the invisible gas which have a strong, distinctive odor that is unlike anything else, except apparently female buds in some strains of the marijuana plant. It is also used as an odorant in propane gas, so make sure you check for a gas leak. If you’ve checked under your rig and found no evidence of having hit or run over an already moribund animal, it is possible you are smelling the spray of a skunk from up to nearly a mile or 1.5km away – this stink is that strong. Or, you possibly have some neighbors partying nearby. If you, your pet or your rig was sprayed by a skunk, avoid touching the liquid spray and wash repeatedly with tomato juice to remove the odor. You can also use Tecnu, a product specifically designed to remove oils and resins of poison ivy and oak that will  also remove the skunk odor.


If you’re driving and you smell smoke, check your gauges for overheating. Be prepared if you are going to stop to check out any smoke smell or visual indication of fire to exit your vehicle quickly. Vehicles can be consumed by flames immediately upon stopping due to the sudden lack of an overflow of air. Always keep a fire extinguisher at the exit of your vehicle. If you have the smell of cigarette smoke in your RV, you can try using an ozone machine to remove the scent.

If the smell is coming from outside your RV, look around for another rig possibly emitting smoke, or a nearby campsite where smokers have congregated. A smoldering cigarette or ash can could also be to blame.

Sour, Slightly Foul Smells

Most often in our rig, a sour smell is the result of bacteria overgrowth in the wastewater tanks. If you’re smelling an odor coming from the shower stall, the sink drains or throughout the rig when the ventilation is drawing air through the space, and you don’t employ a regular tank cleaning protocol, you probably need to do a cleanup of the wastewater tanks. We recommend and use the Geo Method, only we don’t use chemical bleach in our tanks, due to a sensitivity to the fumes. If you are storing your RV for a short time, but not winterizing it, make sure you use stoppers in your grey water drains to force any gasses to vent through the vent pipes instead of into your rig.

Also check your refrigerator or pantry for anything that could be past its prime. Rotting vegetable matter has a funky, overwhelming odor that can be foul, smelling of rotting garbage or like a swamp or marsh.

Sweet or Cake-like Smells


Photo credit: Evelyn Giggles

Sweet odors can be a sign of many different issues with your RV. It could be a sign of your engine overheating, the heater core leaking (described as a maple syrup smell) or an antifreeze or other coolant leak into the climate control system that is causing a sickly sweet (even cake-like) odor in your motorhome. In any of these cases, you want to have your RV checked out quickly by a professional to identify and fix the source of the smell. It could just be your fruit bowl, though – do you have a small swarm of fruit flies as well? Have you maybe left a glass of wine sitting around?

Want to save this for later? Pin this post!


Did I miss any smells? What stinks have you found in your RV that I didn’t mention?






: Check out their website



Cost: Free!


Related posts


Leave a Comment

We'd love to hear your thoughts!