Buying a Used Car in UAE: Engine Checks You Must Do
The UAE used car market is large and active, with a wide range of vehicles available at all price points. However, a significant proportion of used vehicles on the market are high-mileage imports or poorly maintained taxis and rental fleet cars. Knowing how to check engine health before committing to a purchase can save you from an expensive mistake.
Check the Engine Oil
Pull the dipstick and examine the oil. It should be amber to dark brown with a clean consistency. Milky, frothy or grey oil indicates coolant contamination, which is a strong sign of a blown head gasket or cracked engine block. Thick black oil with a burnt smell means the oil has not been changed regularly. Either finding warrants serious caution.
Inspect the Coolant Reservoir
The coolant reservoir should contain clean green, blue or orange coolant at the correct level. Oily or dark coolant indicates possible head gasket failure. A constantly low coolant level with no visible external leak suggests the coolant is being consumed internally through a gasket fault.
Start the Engine Cold
Always inspect a used vehicle with a cold engine if possible. A cold start reveals problems that disappear once the engine warms up, such as excessive smoke, rough idle and noisy valve train. White smoke on cold start is normal in cool weather but persistent white smoke on a warm engine is a red flag for a head gasket issue.
Request an Engine Compression Test
A compression test is the most reliable way to assess internal engine wear and cannot be faked by a fresh oil change or clean engine bay. Each cylinder should produce pressure within 10 percent of the others. Any cylinder significantly below the average, or below 130 PSI for a typical petrol engine, indicates worn rings or damaged valves that will require costly repair.
OBD2 Diagnostic Scan
Request an OBD2 scan to read any stored fault codes, including pending codes that have not yet triggered the check engine light. A clean scan does not guarantee a fault-free vehicle but a scan with multiple fault codes, particularly relating to the fuel system, emissions or misfires, is a strong signal to walk away or negotiate a significant price reduction.
Test Drive and Listen
Drive the vehicle on both city roads and at highway speed if possible. Listen for knocking, rattling or hissing from the engine bay. Any abnormal noise under load, a hesitation when overtaking or a temperature gauge that rises in traffic should be investigated before completing the purchase.