Timing Chain Replacement in Tyne and Wear

A timing chain links the crankshaft to the camshaft or camshafts so the valves open and close at exactly the right moment. Unlike a rubber belt it runs inside the engine, lubricated by engine oil, and is often expected to last a long time. It is not a lifetime part, though.

What wears is usually not just the chain. The tensioner, the guide rails and the sprockets wear alongside it, so the job is normally done as a set.

Signs the chain is wearing

The classic sign is a rattle or scraping from the front of the engine on a cold start that may fade as oil pressure builds. Do not ignore it because it goes away. A stretched chain can jump a tooth, which upsets the timing.

Modern engines can also store a fault code when the camshaft and crankshaft positions no longer agree. If a warning light comes on with a rattle, or the engine runs badly, stop driving and get it checked. On many engines a failed chain can cause the valves and pistons to collide.

• Rattle on start-up, especially when cold
• Engine management warning light with timing-related codes
• Rough running or loss of power
• Metal particles in the oil
• Poor oil servicing history

What the job involves

It is a bigger task than it sounds. The chain sits behind a cover on the front or sometimes the back of the engine, so access can mean removing ancillaries, mountings and the sump on some designs. The old chain, tensioner, guides and sprockets are inspected and the timing is set using the manufacturer's marks or locking tools.

At Banks of the Tyne in Hebburn we replace the chain with a matching kit rather than just the chain, because a new chain on worn guides soon stretches again. Seals disturbed on the way are renewed, the oil is changed and the engine is checked for correct running afterwards.

What affects the outcome and the cost

Engine design is the main driver. Some chain engines are straightforward; others need the engine or subframe lowered to reach the cover, and the labour reflects that. Kit contents and any extra seals also feed into the estimate.

Oil history matters. Chains depend on clean oil for the tensioner to work, so a neglected engine is more likely to have worn parts elsewhere. If the chain has already jumped, we will need to check the valves and pistons before anyone can say the repair is enough.

• Engine layout and access
• Parts included in the kit
• Whether timing has already slipped
• Oil condition and service history

What to expect and when not to proceed

We start with a diagnosis, because a rattle can also come from other places. If the chain is confirmed, we explain what is needed at the estimate and you decide. If damage has gone further, a wider engine repair or replacement may be a better route, and we will say so.

Tell us when you hear the noise, whether it is worse cold, and what service work has been done. Avoid driving the car if the noise is getting worse.