01-05-2025
Beware the used car buying scam that makes your vehicle appear faulty...
A scam targeting private car sellers appears to be making a comeback - and drivers planning to advertise their motors for sale need to be vigilant for the dirty tactic deployed by fraudsters.
It sees con artists arriving to test drive a car listed for sale by owners, only for them to tamper with the engine bay to make it appear like there's a major issue.
They do so by pouring oil into the coolant system. When the engine then billows smoke, the unlawful potential buyers will claim there's an issue.
But instead of walking away from an apparent faulty vehicle, they offer to take it off the seller's hands for around a third of the asking price.
The criminals usually work in pairs, with one distracting the owner while the other decants engine oil into the coolant system.
The Daily Mail has reported on numerous instances of the 'dirty oil trick' being raised to police in the last few years, as criminals attempt to con unsuspecting car owners out of thousands of pounds.
One instance saw two brazen scammers attempt to con an unsuspecting BMW owner from Norfolk out of £6,000 by pouring engine oil under the bonnet before asking him to sell it on the cheap.
How the dirty oil trick scam usually works
Each time a scammer attempts this trick there are of course nuances - but it typically follow a similar pattern.
The scammers will express interest in a car that a private seller has advertised and schedule to visit to view and test drive it.
Usually the scammers will come in pairs or threes, sometimes even with kids in tow.
While inspecting the car and the engine, one of the group will distract the owner - asking to see the paperwork, or the spare wheel etc - while another one of the group contaminates the coolant with oil.
A few quick squirts of oil into the coolant system (and often the exhaust pipe too) will cause the car to smoke when it starts or shortly after embarking on a test drive.
When smoke starts billowing, the criminals will then ask to check the engine again and claim it is about to fail.
This will trigger a derisory offer to buy the car for scrap.
This is Money has heard of a number of cases of this tactic returning.
The Daily Mail has previously reported a spate of instances over the last few years.
In 2022, BMW owner Bikramjit Kooner caught two shameless scammers on CCTV attempting to con him into selling his 10-year-old 520D M Sport for a faction of the price he was asking on eBay marketplace.
While one man distracted Kooner, the other put engine oil into the coolant and put more oil on the side of the engine to make it smoke.
After the car started smoking on the test drive, they told him it was 'fucked' and offered to buy the car 'as scrap for £2,000'.
Similar experiences happened to husband and wife Martin and Natasha Hill from Kent in 2019, and John Woodcock from Manchester in 2016.
Mr and Mrs Hills were trying to sell their Audi A4 through classified advertisement website Gumtree when the same 'dirty oil trick' was pulled and the two men offered £1,000 to £2,000 less than the asking price - on certain 'conditions'.
This too was caught on CCTV, as was John Woodcock's experience with three Bulgarian men who came to view his BMW E39 in 2016.
He'd posted it for sale on Gumtree for £1,750, but the men only offered him £500 after distracting him and emptying a bottle of oil under the bonnet and claiming 'damage'.
In all cases the cars luckily didn't suffer lasting and expensive damage because the owners were wise to the scheme before attempting to drive them, so the systems could be flushed.
How to make sure you don't fall foul of the 'dirty oil trick' scam when selling your car
Firstly make sure you have someone with you, a friend or family member, when anyone comes over to view your vehicle. This will make sure there's always someone with eyes on the front of the car, watching for suspicious behaviour.
Take pictures of your car's engine bay and coolant bottle, which clearly shows the coolant colour and the oil colour. The time stamped photos will be proof to compare back to.
Clearly demonstrated the oil dipstick, the cap and the coolant colour and cap before you start the engine and go for a test drive - it will show any potential scammers you're aware of the trick.
Make sure you and your friend or family member do not leave the car viewer unattended at any point.
If you discover anything's been tampered with then don't drive the car until you can get a mechanic out to fix it - this way you can save yourself money on potentially costly repairs.
