Cruising along with the windows up, you might catch a whiff of a sweet aroma in your car and think someone's popped in a delightful air freshener or it's the lingering scent of a new car.
However, an automotive expert warns that this seemingly innocuous smell could actually be a cry for help from your vehicle.
Many drivers would brush off such a scent without a second thought, especially since it isn't a burning odour which would typically raise alarms. Yet, specialists are flagging this particular sweet smell as a critical alert from your motor. This comes after the news of 'anyone buying fuel next week given '£15 charge' warning by The AA'.
"Drivers often dismiss sweet smells in their cars as nothing to worry about, but this particular scent is one of the most misunderstood warning signs I encounter," said Kazimieras Urbonas, Supplier Excellence Manager at Ovoko.
The spokesperson for one of Europe's leading online marketplaces for pre-owned car parts said: "What might seem pleasant can indicate a serious problem that, if left unchecked, could leave you with repair bills exceeding £1,000."
That delightful sweet smell, which becomes more pronounced when the engine heats up or the heater is on, is usually a sign that your car's coolant system needs urgent attention, reports the Daily Record.
Urbonas explained that the scent is most likely coolant, or antifreeze, and ignoring it could lead to catastrophic engine failure. This is because the coolant shouldn't be seeping into the interior of your car. The liquid emits a distinctively sweet, almost syrupy odour that can easily mislead drivers into believing it's benign.
"Coolant has ethylene glycol in it, which gives off that characteristic sweet odour," explained Urbonas. He continued, adding: "The problem is that when you can smell it inside your car, it means the coolant is escaping from where it should be, usually through a leak in the heater core or damaged hoses".
You'll often detect this aroma most strongly in the footwell area, wafting through the air vents, or pervading the entire cabin. It tends to become more noticeable when your engine is running hot or when the heating is on, as these conditions increase the strain on the cooling system.
A faulty heater core is frequently to blame for this sweet-smelling issue. Located behind your dashboard, it utilises hot coolant to heat the air entering your cabin, and if it leaks, coolant may drip into your vehicle's ventilation system.
"Heater core problems are particularly sneaky because they're hidden away behind the dashboard," shared Urbonas. "You might not see any obvious puddles under your car, but the coolant is still escaping – it's just doing so inside your vehicle instead of underneath it," said the manager.
Damaged coolant hoses are another potential cause for concern. These hoses transport coolant around your engine bay and can, over time, suffer from cracks or loose connections that let coolant leak out and evaporate, leading to that sweet scent infiltrating your car.
It's typical for motorists to presume the scent originates from something innocent, but this is an error. Air fresheners, cleaning products used during car washes, or even certain synthetic materials in newer vehicles can produce sweet fragrances that appear similar.
Urbonas went on: "I've had customers tell me they thought someone had spilt perfume in their car, or that their air freshener just happened to be particularly strong that day. The dangerous part is that people often adapt to smells over time, so what starts as noticeable can become background noise, until the real damage is already done".
Dismissing this sweet aroma can result in several serious complications. Engine overheating is the most immediate worry, as your cooling system can't function properly with insufficient coolant levels. Beyond mechanical harm, there are health considerations too. Coolant vapours can be toxic, particularly in confined spaces, and extended exposure isn't something you want to risk.
He warned that "what people may not realise is that coolant leaks can also lead to mould growth in your ventilation system. The moisture creates perfect conditions for mould and bacteria to thrive, which then gets blown directly into the cabin every time you use your air conditioning or heating".
Misty windows that pop up out of the blue could also be a sign of coolant vapour inside your vehicle. This occurs when coolant evaporates and then settles on the glass surfaces of your car.
"Don't try to diagnose exactly where the leak is coming from yourself," ended the expert. Concluding by urging drivers to "get your car to a qualified mechanic who can perform a pressure test on your cooling system. This will show exactly where coolant is escaping and how serious the problem is".
Finally, Urbonas said: "From my experience in the parts industry, heater core replacements are among the more expensive repairs car owners face. The part itself isn't necessarily costly, but the labour involved in accessing it – which often means removing the entire dashboard – can push repair bills well over £1,000".