Parts for your 2008 Ford Transit-Ignition coils

2008 Ford Transit ignition coils — what they do and when to replace

Based on Ford Workshop Manual (TIS/ETIS, Section 303-00 Powertrain), Autodata, and Haynes coverage for the Mk7 Transit (2006–2013), ignition coils are used on 2008 Ford Transit models fitted with the 2.3-litre Duratec petrol engine (coil-on-plug layout). The Duratorq TDCi diesel variants, which make up most Australian and New Zealand deliveries, are compression-ignition engines and don’t use ignition coils at all, they rely on high cylinder pressures and fuel injection to ignite the charge, with glow plugs assisting cold starts. So, ignition coils are relevant for petrol Transits only, and not applicable to diesel models.

On the petrol 2008 Transit, the ignition coils transform the 12V battery supply into a high-voltage spark right at each plug. Mounted directly on the spark plugs (coil-on-plug), they improve spark accuracy and reduce energy losses versus old-school leads. When they’re healthy, starting is crisp, idling is smooth, and fuel economy stays on-song.

Coils aren’t a scheduled replacement item in Ford’s service program, but they do age from heat, vibration, and moisture. During regular servicing, it’s smart to check for cracking on the coil bodies, oil in the plug tubes, and brittle boots. If misfires crop up under load or at idle, scan for codes like P0300–P0304 and inspect the affected coil. A quick swap test (moving a suspected coil to another cylinder) can confirm a fault if the misfire follows the coil.

• Common symptoms: hard starting, rough idle, hesitation, poor fuel economy, and a flashing MIL under load.
• Good practice: replace spark plugs at the interval specified for your plug type, and renew coil boots if they’re swollen, torn, or carbon-tracked.
• Environment matters: coils hate water intrusion from washing or leaks—keep the plug wells clean and dry.

When replacing, use quality OE-equivalent coils and ensure the sealing grommets seat properly in the rocker cover to keep moisture out. The coil hold-down bolts are small, torque them to the Ford spec from the workshop manual, not “by feel.” A smear of dielectric grease on the inside of the boot helps future removal and guards against tracking. If multiple coils are the same age and one fails, it’s reasonable to replace the set to avoid repeat visits—particularly on higher-kilometre vans working hard. Technical references from Ford TIS and Autodata support coil-on-plug diagnostics, correct torque data, and misfire test routines for the 2.3L Duratec HE engine.

FAQs

Does a 2008 Ford Transit diesel have ignition coils?
Diesel Transits (Duratorq TDCi) don’t use ignition coils because they’re compression-ignition engines. They ignite fuel from heat generated by compressing air, using glow plugs only to aid cold starts. Only the 2.3L petrol Transit uses ignition coils.

How long do ignition coils last on a 2008 Transit petrol?
There’s no fixed lifespan, many see well over 150,000 km, but heat and oil contamination can shorten it. If a coil fails, it’s fine to replace just the faulty unit, though on high-kilometre vehicles replacing all four can prevent repeat misfire call-backs.

What are the signs my ignition coil is on the way out?
Look for rough idle, hesitation on hills, a flashing check engine light under load, or poorer fuel economy. Scan for misfire codes (P0300–P0304) and inspect the coil and boot for cracks, tracking, or oil in the plug tube.