Mercedes Engine Repair London | Timing Chain, Head Gasket, Injectors

Mercedes Engine Repair in West London

We carry out major engine repair on Mercedes OM642, OM651, OM654, M271, M274 and M276 engines — including timing chain replacement, head gasket work, injector replacement, turbo replacement and the well-known M272/M273 balance shaft repair.

Price: Quoted after diagnosis. We do not guess engine repairs. Typical time: 1–5 days depending on job

Big engine jobs are where a Mercedes specialist earns its money. We have done enough timing chains, head gaskets and injector jobs on these engines to have stopped guessing. We quote from reality, not a flat-rate manual.

Timing chain replacement

M271 Kompressor and some early M272 engines can suffer stretched timing chains at high mileage — the tell-tale is a rattle on cold start and a "camshaft position / crankshaft correlation" fault code. We replace chain, guides and tensioner as a set, in the car.

Head gasket and cylinder head

OM651 head gasket failure and OM642 oil cooler seal failure are the two most common "coolant vanishing" faults we see. We pressure-test the cooling system to confirm the source before any strip-down.

Injectors

Diesel injector failure on OM642/OM651 will show as rough idle, smoke, misfire, and sometimes broken glow plugs (if they have been leaking for months). We flow-test, replace as a matched set where needed, and code injectors to the ECU on Xentry.

What's included

Timing chain replacement (in-car)
Head gasket replacement
Injector replacement + SCN coding
Turbo replacement
Balance shaft repair (M272/M273)
Oil cooler / oil filter housing reseal (OM642)

Common symptoms we see

Rattle on cold start
Misfire / rough idle
Coolant disappearing
White or blue smoke
Turbo whine / overboost fault

Frequently asked questions

Is a major Mercedes engine repair worth doing?

On well-kept cars, yes — most Mercedes engines are easily good for 250,000 miles after one major repair. We will give you a fixed-price quote and an honest view of the car's remaining life before you decide.

What does a stretched Mercedes timing chain sound like?

A metallic rattle on cold start, usually lasting 1-3 seconds and going quiet when warm. Often accompanied by a "camshaft / crankshaft correlation" fault code.

What are the common faults on the Mercedes OM642 V6 diesel?

Oil cooler and oil filter housing seal leaks (the classic "disappearing coolant and oil" fault), EGR cooler leaks, swirl motor failure and occasional injector wear. We rebuild the oil cooler area as a fixed-price job.