OEM supplier of Ford’ s wet belt, Dayco, has said that dieselcontaminated oil can harm the belt in EcoBlue engines found in the Transit
belt, every time one of these vehicles enters the workshop.
‘ Technicians should smell it for diesel fumes and check the strainer that the oil will have passed through, because it’ s possible that fragments of the belt or deposits of material that have been dislodged will be left behind.
‘ When it comes to the belt however, things are a little trickier, but although awkward, it is possible to assess the condition of the back of the belt by viewing it through the oil filler, a check that Ford also states should be regularly made.’
While smelling for diesel isn’ t transferable to the EcoBoost petrol engines, the other checks are appropriate.
When changing the wet timing belt, all of the flywheel locking and cam locking tools should be used so the timing isn’ t altered when swapping the belt. It is also prudent to replace the crankshaft oil seal before refitting the timing cover. This has proved, for some garages, to be easier once the cover is secured back in place – then it’ s ideal to remove the old seal before installing the new one. It’ s also best practice to replace the water pump, remembering to prime
Dayco suggests a belt check every time an EcoBlue enters a workshop, including smelling the oil for diesel
Autumn / Winter 2026 The Engine Rebuilder 55