2019 Ford Tourneo Custom 2.0L Diesel · SM04 DON

The 2.0-litre EcoBlue diesel engine introduced in late 2016 employs an oil-submerged timing belt and oil pump drive belt (wet belt). Fuel dilution resulting from aborted DPF regenerations, extended oil service intervals, and non-conforming engine oil rapidly deteriorate the rubber belt material. Flaked rubber particles wash down into the sump and form a dense mat over the oil pick-up strainer mesh. Oil flow to the camshaft journals, rocker arms, and turbocharger bearing assembly is choked, triggering low oil pressure alerts. If ignored, catastrophic engine seizure or turbo failure results.

Euro 6 EcoBlue models use Selective Catalytic Reduction (SCR) with AdBlue diesel exhaust fluid. The AdBlue tank heater element integrated into the pump assembly frequently burns out, preventing the reductant fluid from thawing or heating to operational temperature in British winter weather. Furthermore, upstream and downstream NOx sensors become fouled with soot, while the AdBlue injector nozzle in the exhaust downpipe crystallises and blocks. When the powertrain module detects emission system faults, it initiates a non-resettable mileage countdown, preventing engine restarts once the countdown reaches zero.