Mercedes Garage
Mercedes Diesel Timing Chain & Injector Repair
Expert workshop repair for OM-series diesel engines — timing chain replacement, injector seal renewal, and full system recalibration. Rebuilds start from £2,200.
15+ yrs
Mercedes specialists
1,800+
engines rebuilt
12 mo
unlimited-mileage warranty
What This Service Involves
Our workshop carries out full timing chain and injector seal repairs on all Mercedes OM-series diesel engines — including OM640, OM607, OM608, OM651, OM654, and OM642. The work is carried out to manufacturer specifications using genuine or OEM-quality parts, with full diagnostic calibration afterwards.
The complexity of the job varies by engine family. For example, the OM654 has its timing chain mounted at the rear of the engine, which requires the engine to be removed from the vehicle for access. The OM642 V6 allows for a “rolling” chain replacement method without removing the front timing cover, but any work on the chain guides still demands a full strip-down. Our technicians are trained in all these procedures and use the correct Mercedes-Benz locking and timing tools for every job.
All injector seal replacements are followed by IMA coding using XENTRY diagnostic software to ensure the engine management system recognises the new injector calibrations.
Our Fixed-Price Rebuilds
4-Cylinder Diesel (OM607/608/640/651/654) — from £2,200
6-Cylinder Diesel (OM642) — from £2,800
Price includes full disassembly, parts, labour, and final testing. Pricing disclaimer.
Inside our workshop
Mercedes Diesel Timing Chain & Injector Repair
Applicable Models & Engines
We carry out timing chain and injector seal repairs on all Mercedes diesel models equipped with the following engine families. Select your model or engine below to see dedicated pages.
Engine Families Covered
Our Process
- 01
Initial Assessment
We inspect the engine and confirm the scope of work – whether timing chain, injector seals, or both. We lock the engine at TDC using factory tools.
- 02
Engine Preparation
For OM654, the engine is lifted out for rear-chain access. For front-chain designs (OM651, OM642), we remove the front ancillaries and timing cover.
- 03
Chain Replacement
Using the “rolling” method (OM642) or direct replacement, we install a new chain, tensioner, and guides. All components are torqued to specification.
- 04
Injector Seals
We remove each injector, clean the bore, fit new copper seals, and reinstall with correct torque. Seals are replaced during chain work where possible.
- 05
Reassembly & Timing
We reassemble all components, set final timing, and rivet the master link. The engine is manually turned to verify timing accuracy.
- 06
Calibration & Testing
Using XENTY, we perform IMA coding (if injectors changed) and run a full system test. The vehicle is road-tested to confirm repair quality.
Why Choose Us for Your Mercedes Diesel Repair
- Specialist Mercedes workshop with 15+ years of experience (founded 2009)
- Factory-trained technicians using genuine Mercedes-Benz tools and XENTY diagnostics
- Transparent pricing – fixed-price rebuilds from £2,200, no hidden charges
- Nationwide recovery service from £70 – we bring your vehicle to our Essex workshop
- 12-month unlimited-mileage warranty on all parts and labour
- Engine removed/replaced with care – we match your exact engine code and VIN
Meet our workshop and see how we work.
How It Works – From Booking to Collection
- 01
Call or get a quote online – we'll discuss your engine and arrange recovery if needed.
- 02
Vehicle arrives at our Essex workshop. We carry out a full inspection and confirm the repair scope.
- 03
We complete the repair (typically 3-5 working days for chain/injector work) and test thoroughly.
- 04
You collect your vehicle with a full report and 12-month warranty – or we arrange delivery.
Related Services We Offer
Frequently Asked Questions
How long does a timing chain or injector seal repair take?+
Typical turnaround is 3-5 working days from arrival at our workshop. More complex jobs (e.g. OM654 rear-chain) may take slightly longer. We'll give you an estimated completion date when we start the work.
Do you use genuine Mercedes parts?+
We use genuine Mercedes-Benz or OEM-quality parts (chains, tensioners, seals) to ensure reliability and compatibility with your engine.
Do I need to bring the car to you, or can you collect it?+
We offer nationwide recovery from £70. Most vehicles are collected within a few hours of booking. Alternatively, you can drop it off at our Billericay workshop.
Is the work covered by a warranty?+
Yes. All our timing chain and injector seal repairs come with a 12-month, unlimited-mileage warranty on parts and labour.
What is the price range for this repair?+
For 4-cylinder diesel engines, rebuilds start from £2,200. For 6-cylinder V6 diesels (OM642), from £2,800. The final price depends on the exact engine and any additional parts needed.