When cars star burning rubber in the movies, it usually means something cool is about to happen. The big chase scene is starting; the hero is off to save the woman he only just realized he loves, something is about to be blown up by a giant robot or a giant alien or a giant alien robot.
In real life however, if you start to detect an odor of burning rubber whist driving your car that’s usually not a good sign. If you have noticed any strange smells lately whilst driving in your car or truck, then this article is designed to help you.
Possible Causes
Just to point out real quick, in this article we’ll be discussing a burning rubber smell, its possible causes and its repairs. There is however a whole range of smells out there all with different causes.
You will know your car way better than anyone else, so if it does start making a smell out of the ordinary, then you’ll probably notice it pretty quickly. The other smells to look out for range from a burning paper smell to Maple syrup (which actually sounds quite nice).
Here though, we’re just talking about the not so pleasant smell of burning rubber. You’ll probably notice it most when your engine has been running for a while, maybe after a long trip.
So the first thing to do after you notice the smell is to let the hot engine cool down a bit, before you pop the hood and start looking for:
Loose Rubber Hose
Like the old saying goes, if you hear hoof beats look for horses not for zebras. How does that connect to your car? Well, if you smell burning rubber, it could just mean that some rubber is burning.
That’s why this is number 1 on the list by the way, so you can check this out before moving on to the next potential causes.
The engine of your car contains a number of rubber hoses, all integral to the engine operation. Over time, they can work loose or lose their securing clips and pins through vibrations. If they move out of place and come into contact with a hot part of the engine, they will start to burn and produce a telltale aroma.
So have a look under the hood to makes sure all the rubber parts are where they should be, and secure them into position if not.
Gasket Oil Leaks
If a gasket or a gasket seal has failed, then this could lead to oil leaking. If this oil comes into contact with a hot part of the engine (like an exhaust manifold) then you will get a burning rubber smell.
As a temporary measure, such as during along trips or when you can’t get to your mechanic, you can manually tighten the coupling surface on the gasket. That should keep the leak at bay enough for you to complete your trip.
At the end of the day though, a leaking gasket has to be replaced sooner or later – for the long-term health of your engine, it really should be sooner.
AC Compressor Heating
The Air Conditioning in your car runs via a compressor that is located under the hood, adjacent to the main engine block. Just like any AC, the one in your vehicle is full of chemical refrigerant that is gradually reduced in volume as the compressor operates.
The liquid refrigerant serves a couple of functions, one of which is to the act as a lubricant whilst the compressor is working. So as the levels reduce, so there is less lubrication and the compressor can start to run “hot.”
This in turn leads to the dreaded burning rubber smell. The best way to avoid this is to ensure that during regular services your mechanic is checking the refrigerant levels in the compressor, and topping up as required.
Electrical Fault
A fault in the electrical system of your car or truck can often present as a sudden burning rubber smell. The odor itself will typically drift in through the AC ducts, and it may not last for too long, as the burnt fuse doesn’t make a continuous smells like some of the other problems on this list.
So if you smelt burnt rubber briefly then it went away, chances are good it is an electrical fault. Pop the hood and inspect all the fuses under there. You can also trace all the cables you see to check their connecters, as a fault here can also make a burning rubber smell.
Make sure all replacement fuses match the stated numbers in the vehicle manual – or take the car to a pro mechanic to double check any replacements are the correct type.
Coolant Leakage
Your engine uses coolant to help prevent overheating during operation. Ok, we’re sure you knew that already, but do you know what burning coolant typically smells like? That’s right – burning rubber.
The coolant that your engine uses is held in an internal tank within the engine block. If this tank is damaged – through vibration or simple old age, for example – it can crack and start to leak coolant.
When the coolant comes into contact with hot parts of the engine, you get a burning rubber smell! This is bad news, as your engine really relies on that coolant for safe and efficient operation. A damaged coolant tank should therefore be repaired as soon as possible.
Garbage
So far, we’ve looked at things that can go wrong with your car and case a bad smell. Sometimes however it’s not your car’s fault – sometimes it can be external factors that are the issue.
If your car accidently picks up garbage as you’re driving, this can sometimes get stuck on the exhaust system under the car. The pipes and other elements of the exhaust system can get really hot during operation, especially on long drives. Pieces of garbage – like plastic bags – will quickly melt when in contact with the exhaust system and produce a very unpleasant smell.
Try to avoid driving directly over garbage. If you get the old smell then always wait for the exhaust system to cool completely before you attempt to remove any trapped garbage.
Oil Leakage
Another thing that can leak is the motor oil in your car. Because of its placement and usage within the car, it will typically leak onto the exhaust system. When it does this it will burn and create a smell.
If you suspect leaking motor oil, simply leave the vehicle parked in one place for a while. Then get down onto your hands and knees and peer underneath. Leaking motor oil will form a telltale – and easy to spot – pool of black liquid underneath the car.
This is a serious fault and you should take the car to a mechanic as soon as possible. Motor oil is pretty flammable, and the exhaust system can reach temperatures above the ignition point of the oil – so in the worst-case scenario, an oil leakage can lead to a devastating vehicle fire starting.
Damaged Drive Belt
Finally, a number of components within the engine rely on a drive belt for operation. This could be the AC compressor we mentioned above, it could be the pumps for water or air and it could be the alternator.
If any of these components seize up, then the drive belt will be left spinning against the pulley. Friction will quickly start to build and since the drive belt is typically made of – you guessed it, rubber – you will soon start to notice a burning smell. Typically, this problem will also be accompanied by a high-pitched squealing sound – so it’s pretty easy to identify.
Again, this can be the symptom of a serious problem with the engine, so get it to a mechanic as soon as possible. The underlying issue will need to be repaired, and depending on the damage caused to it already, you may also need a new drive belt.
Precautions & Advice
So whilst the smell itself may not be very pleasant, it can be a very useful symptom for discovering an issue with your car engine in the early stages. Catch it – and repair it – in these early stages and you could save yourself some considerable cash in the long run.
As a general rule of thumb, if you smell something bad always ensure that you:
- Wait until the car engine has cooled completely before starting your inspection.
- Take note of secondary symptoms or observations that could point toward one of the issues above. For example, the squealing sound that accompanies drive belt damage or telltale oil slicks from a leak.
- Start your inspection with the engine block as most issues originate under the hood.
- The exhaust system is also worth a look if your inspection under the hood throws up no signs of problems.
- Remember that this smell can often be the early symptom of a more serious problem. If you can smell it but can’t find the cause, it’s a good idea to bring your car to a mechanic for a more thorough inspection.
Sources:
- HOW TO ASSESS STRANGE AUTOMOBILE ODORS – dummies
- Car Smells like Burning Rubber – Possible Causes & Solutions – Mechanic Base
