21/04/2026
From Wiltshire Police
We are seeing an increase in reports of a scam targeting people selling vehicles privately through sites such as AutoTrader, eBay, and Facebook Marketplace. This scam is often referred to as the “Dirty Oil” scam and can lead to sellers being pressured into selling their car for far less than it’s worth.
How the Scam Works
The Set Up
Fraudsters pose as genuine buyers and arrange to view a privately advertised vehicle. They often arrive in pairs and act very enthusiastic and knowledgeable about cars.
The Distraction
While one individual distracts the seller (for example by asking to see paperwork, the boot, or discussing a test drive), the other secretly sabotages the vehicle. This is typically done by:
• Pouring oil into the coolant reservoir
• Pouring oil onto hot engine components or the exhaust/tailpipe
The “Engine Failure”
Soon after, the engine appears to fail dramatically, producing thick white or blue smoke. The scammers claim the engine is “blown” or that the car needs a major and costly repair.
The Pressure Sale
They then offer a very low amount (often 30% or less of the asking price), claiming they are doing the seller a favour by “taking it off your hands as scrap”. The goal is to pressure the seller into a quick, panicked decision.
Warning signs to watch for
• Buyers insist on coming in pairs
• One person distracts you while the other stays near the engine bay
• Sudden catastrophic “engine failure” during or immediately after a short test drive
• Aggressive pressure to accept a low offer on the spot
• Claims that repairs will cost “thousands” without any proper inspection
How to protect yourself
Never leave buyers alone with your vehicle
Keep the car in sight at all times. Be especially watchful if the bonnet is opened.
Have someone with you
A friend or family member present makes distractions much harder.
Check before and after viewings
• Inspect the coolant reservoir for oily residue or dark contamination
• Look for fresh oil around the engine bay or exhaust
• If possible, take photos of the engine bay and coolant tank before viewings
Be sceptical of sudden failures
A well maintained car does not usually suffer dramatic engine failure out of nowhere. Heavy smoke appearing suddenly is a major red flag.
Trust your instincts
If something feels wrong, stop the viewing immediately.
If you suspect a scam
• Refuse the sale and ask the individuals to leave
• If they refuse to leave or become threatening, call 999
• If the suspects have already left, report the incident to Report Fraud
Share this warning
Please share this message with friends, family, and neighbours – especially anyone selling a car privately. Awareness is the best defence against this type of fraud.