Timing belt in the oil: what to check on a PureTech, EcoBoost or EcoBlue.

Which engines

• Ford 1.0 EcoBoost petrol, from 2012: Fiesta, Focus, EcoSport, B-Max, C-Max and others. The oil pump has its own belt in the oil too, and later versions that moved the camshafts to a chain kept that oil pump belt.
• Ford 2.0 EcoBlue diesel, from 2016: Transit, Transit Custom and Tourneo, and some Ford cars (check by the VIN).
• PureTech 1.0 and 1.2 petrol, from 2012: a lot of Peugeots, Citroens, DS and Vauxhalls, until the newer chain engines.

Not sure which yours has? Send me the reg.

What goes wrong

The belt sits in the engine oil. Fuel getting into the oil (lots of short trips, or the exhaust's particulate filter cleaning itself), the wrong oil, or oil left in too long makes the rubber swell and break up. The bits can block the strainer on the oil pump's pickup, the oil pressure drops, and the engine can fail.

Signs to watch for:

• the red oil pressure light;
• cam timing fault codes;
• on a PureTech, a brake pedal that suddenly goes hard. Bits of belt can block the brake vacuum pump, and there have been UK recalls for it.

A 2016 Fiesta 1.0 EcoBoost I diagnosed had the red engine light and the red oil light flashing, and live data showed the camshaft's actual and desired positions not matching. My diagnosis was a blocked oil pickup or a sticking cam phaser. The owner did the fix himself, so I can't say what caused it. On these engines, those signs mean get the belt checked.

When the belt is due

Whichever comes first:

• Ford 2.0 EcoBlue in the Transit, Transit Custom and Tourneo: 6 years or 100,000 miles, down from 10 years or 150,000. Ford says oil dilution, which can happen when the exhaust filter cleans itself, and how the van is used can wear the belt early. In a car with this engine, check by the VIN.
• PureTech 1.0 and 1.2: 6 years or 100,000 km (about 62,000 miles).
• Ford 1.0 EcoBoost: Ford's schedule says 10 years or 150,000 miles, but NTN-SNR's belt sheet says 160,000 km (about 100,000 miles), so check by the VIN.

What you can check yourself

• The dipstick: the level, and the smell. Oil that smells of petrol or diesel is a warning sign.
• The invoices: the right oil spec, not just the thickness on the bottle (for example Ford WSS-M2C948-B on the 1.0 EcoBoost, Ford WSS-M2C950-A on many 2.0 EcoBlues, and the Stellantis B71 spec in a PureTech's handbook), and when the belt was last changed.
• Through the oil filler: on a PureTech you can see part of the belt, and Stellantis recommends checking it there at every service. The proper check is a width gauge, so a belt that looks fine still needs measuring. On the 2.0 EcoBlue you can see the back of the belt. Cracks, frayed edges or missing bits mean get it looked at before you drive it any further. On the 1.0 EcoBoost you can't see it from outside.
• Recalls: put the reg into GOV.UK's vehicle recall checker (or the make, model and year if it won't take the reg).

The right oil matters

When I serviced a 2019 Citroen C3 1.2 PureTech, I used the right spec of oil, because its timing belt runs in the oil.

PureTech owners: check the Stellantis scheme first

Stellantis runs a UK scheme for PureTech engines in Peugeots, Citroens, DS and Vauxhalls. It covers engines built up to June 2022 and can pay for oil pressure faults from early belt wear, up to 10 years or 112,000 miles. A Stellantis dealer has to diagnose and repair it, and you'll need invoices showing on-time servicing with the right oil. The UK terms say dealer servicing, so if your car could qualify, check that before you book a service anywhere else, mine included.

How I got this: from my own jobs, Ford's and Stellantis's published statements, and the belt makers' technical sheets.

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