By: Author John Cunningham. Published: 2023/06/14 at 4:39 pm
You are correct to be concerned; a burning smell from your snowblower is not normal. But don’t panic; I’m John, a mechanic with 20-plus years of experience, and you have done all the right things so far. You’ve noticed the smell, shut down the machine, and are in the correct place to solve this issue.
A loose or worn-out transmission or auger belt usually causes a burning smell from a snowblower. Adjusting belt tension or replacing the belts typically solves the problem.
In this post, we’ll look at the likely causes of a snowblower burning smell and what causes them, and we’ll look at the diagnosis process and the links to a step-by-step beginner’s belt replacement guide.
Causes of a Burning Smell in a Snowblower
The most common issue with a snowblower burning odor is, as said, belt issues; typically, either the auger or the transmission belts are worn out and loose.
A loose belt slips results in a burning odor.
Jump ahead to belt diagnosis here.
That said, there are other possible reasons for the burning odor, and we’ll cover them below.
While a burning smell from your snowblower isn’t usually typical, it can be expected under some circumstances. We’ll cover those circumstances along with all the other less likely reasons your snowblower smells like it’s about to combust.
What’s a Normal Burning Smell?
This section will only apply to those of you who are lucky enough to have a new snowblower. A brand-new machine will offer a faint burning smell as the engine heats up; that’s quite normal.
Typically, paint and greases associated with manufacturing are burnt-off hot components like exhausts and cylinder heads; that said, we are talking about a faint smell of burning here, not an altogether unpleasant smell.
If you’ve ever had a new muffler fitted to your car, you’ll be familiar with the smell.
If you’re smelling an acrid, unpleasant burning smell, it’s not that new snowblower smell, and it suggests we have an issue.
Many new snowblowers are shipped without oil, be sure to top up oil to the correct mark before running any engine.
Here’s a link if you need help with the oil check
An overheating belt is the most likely reason your machine stinks. Your snowblower is fitted with two belts, one to drive the snowblower forward and back, known as the transmission drive belt, and a second belt to power the auger, the auger belt.
Both belts work hard, and while they don’t require a ton of maintenance, an annual pre-season check for wear and to check belt tension is advised.
A loose belt allows the crankshaft pulley to slip, and that, as you can imagine, causes the pulley to heat the rubber belt, which, if ignored, will eventually burn the belt.
It’s not uncommon for the burning smell to be accompanied by smoke.
An overheating engine causes gaskets and engine paint, greases, and oils to scorch, which causes that burning odor. And engines overheat for a few reasons; here, we’ll cover all the most common reasons.
Low oil – The number one reason for overheating is a low oil level. Oil doesn’t just lubricate the innards of the engine. It also cools it as well as cleans and neutralizes harmful combustion acids.
Coffee break – Snowblowers are well fit to operate for prolonged periods, but if the workload is greater than it was designed for, it will overheat.
Maintenance issue – A dry mechanical component such as a dry wheel bearing or auger axle can cause the engine to work extra hard, causing an overheating condition.
Even something as simple as soft tire pressures will add significantly to a snowblowers workload.
Air restriction – Debris blocking the air intake or any issue with airflow around the engine, such as debris or a damaged flywheel fan, will quickly cause an overheating issue.
Mechanical fault – A faulty engine, transmission, or auger component like a dry bearing will cause additional engine load leading to overheating.
Fuel issue – Using fuels other than recommended can cause the engine to run lean, and a lean-running engine runs hot. Similarly, a vacuum leak can cause a lean hot running condition.
Most snowblower manufacturers recommend regular gas or E10; they do not recommend E15 fuels, and E85 will kill it.
There are other possible reasons for a hot-running engine, but these are the main ones.
Oil leaks are common with older machines; usually, that doesn’t cause too many issues. But sometimes, oil leaks can be a real pain in the ass.
A leaking crank seal or rocker gasket can cause oil to drop or mist onto hot surfaces and cause a burning odor.
So long as you keep your oil level topped up, there’s no danger to the engine. But health-wise, walking behind a smoky machine isn’t advisable. Worth noting also oil leaks have a habit of eventually contaminating the belts, and that causes performance issues.
Best to get oil leaks taken care of early; they don’t improve with age.
We’ve previously covered using the wrong fuel type, meaning how we shouldn’t use E15 or E85, but that’s not what this section is about. Incorrect fuel in this context refers to using mixed gas when we shouldn’t or some other substance other than straight gas.
It happens often; mixed gas for the weed wacker is put in the snowblower. No harm done, but the engine will produce smoke, just the same as a two-stroke engine with too much oil in the mix. While two-stroke snowblowers exist, the majority are, as you know, straight-gas four-stroke engines.
I’ve also seen machines get a partial drink of paint thinner or diesel and still run, but not very well, with strange odors and smoke.
Friction disk overheating
The friction disc is a rubber wheel critical for the transfer of power from the drive plate to the drive axle.
Although rare, it is possible for a friction disc issue to cause a burning odor.
How to Troubleshoot a Burning Smell in Your Snowblower
First things first, let’s just check the oil level and make sure all is good in that department before moving on. Here’s a link if you need help with the oil check.
Generally, I’d check over the machine and check for anything out of the ordinary like oil drips; I’d check the gas tank to be sure its contents look and smell like gas; I’d look for any signs of loose, broken, or binding components such as auger assembly or stiff wheel movement.
If you’ve recently had your snowblower on its side, the burning smell, including smoke, is commonly caused by oil inside the combustion chamber. No harm done; you can read more about that one right here – Snowblower on its side
As said earlier, if your snowblower is new, check the oil level before running the engine. They generally ship engines without oil, meaning you must add oil before running the machine. Many engines are lost because manufacturers use very subtle warning labels that excited owners often miss.
To begin diagnosis properly, it is essential to gather some information. Here are the questions I ask a customer over the phone if I can’t inspect the machine in person.
When does the burning odor occur?
- Only when transmission engaged? – This indicates there may be an issue with the drive belt.
- Only when the auger is engaged? – This indicates there may be an issue with the auger belt.
Does the machine move forward and backward without issue?
- Is the drive free from squealing noises?
- Does it feel normal when engaged?
- Does it move without stalling or binding?
Does the auger work without issue?
- Is the auger free from squealing noises?
- Does it feel normal when engaged?
- Does it move snow without stalling?
After answering a few of these questions, you’ll get a feel for which system is most likely at fault and the system we’ll need to inspect further.
As said, burning odor is generally a belt issue, and I have covered belt inspection and replacement previously, including a beginner step-by-step guide with pictures; you can check them out right here:
Auger belt stops when hits snow (covers auger belt inspection and replacement)
Snowblower starts but won’t move (covers drive belt inspection and replacement)
A burning smell from a snowblower is not normal and can be caused by various issues. The most common cause are loose or worn-out transmission or auger belts, which can be fixed by adjusting or replacing belt tension.
Other possible reasons for the burning smell include an overheating engine, oil leaks, incorrect fuel, and friction disc problems.
To troubleshoot the issue, check the oil level, inspect the machine for any abnormalities, and gather information about when the burning odor occurs and the performance of the snowblower. Belt inspection and replacement guides are available for beginners.
The snowblower makes a squealing sound.
You may find these posts helpful:
- How long do snowblower belts last?
- Auger belt smoking
- Snowblower smoking
- Auger stops in snow
- Snowblower won’t move
- About the Author
- Latest Posts
John Cunningham is an Automotive Technician and writer at Lawnmowerfixed.com.
He’s been a mechanic for over twenty-five years and shares his know-how and hands-on experience in our DIY repair guides.
Johns’s fluff-free How-to guides help homeowners fix lawnmowers, tractor mowers, chainsaws, leaf blowers, power washers, generators, snow blowers, and more.