Siemens VDO / Continental 5WS40000-Z Diesel Injector

On the PSA 2.0 HDi (RHY) platform, a failing Siemens VDO / Continental 5WS40000-Z injector typically presents as: hard starting, particularly when warm; uneven idle; loss of power with rail-pressure faults; excess smoke under acceleration; engine stalling at idle.

When two or more of these appear together, suspect the injector before peripheral systems — a comparative leak-off test and live-data cylinder-balance review will isolate the failed unit without tear-down.

The documented failure modes on this platform are: injector back-leak beyond specification on high-mileage units; nozzle wear causing over-fuelling and smoke; fuel contamination damage on neglected systems.

Internal wear cannot be repaired in situ — once delivery drifts outside calibration, remanufacture or replacement is the reliable fix.

This is an early common-rail platform — verify low-pressure supply and check for air ingress before condemning injectors. Run a comparative leak-off test across all four injectors. Use new sealing washers on every refit.

Never condemn a common-rail injector on a fault code alone — codes identify the circuit or cylinder, while leak-off volumes and correction values identify the component.

Each remanufactured 5WS40000-Z is fully stripped, ultrasonically cleaned and inspected; worn components are replaced with OE-grade parts. The rebuilt unit is then calibrated on a common-rail test bench against the manufacturer's specification sheet — delivery, back-leak and response are all verified before the injector is sealed and despatched with its calibration data on file.

Every unit carries a 12-month parts warranty and free UK delivery.

The 5WS40000-Z trusted family covers 18 verified vehicle fitments across 4 makes: Citroen, Peugeot, Fiat and Ford. Every fitment listed on this page is registry-verified — no scraped or assumed applications.

5WS40000-Z supersedes or cross-references 10 further OE numbers, including R5WS40000, 9636819380, 9652173780, 9652173680, 9636680280, 1980F0, 00001980F0 and 1980Y0. Always match the reference etched on your failed unit's body — cross-references within a family are verified equivalents, but etched numbers remain the source of truth.