Injector seal leak (soot around injectors)
Attaches to M57 at engine level · Fuel · carried by 9 variants across 4 chassis
Overview
Injector seal leak (soot around injectors) is a occasional fault recorded against M57 at engine level, typically from 150–300k km. It shows up as ticking that grows louder, black soot deposits around the injector bases, diesel smell in the cabin. Where it's documented, the repair runs €400–€1,400 (seals at the low end; a seized injector that must be cut out is the high end, costs dated 2026-07), and it can be checked before you buy. 9 variants across 4 chassis in this database inherit it.
What happens
Symptom. Ticking that grows louder, black soot deposits around the injector bases, diesel smell in the cabin.
Cause. Copper sealing washers fail and combustion gases track past the injector, eventually welding it into the head.
How to check it
Static checks
Remove the engine cover and look at the base of each injector for black crusting. Caught early this is cheap; ignored it's a cylinder head job.
Engine off, ideally on a lift.
Every variant that carries this
| Variant | Chassis | Body | Years | Risk | Good buy | Cost as % of good buy |
|---|---|---|---|---|---|---|
| 325d M57 | E90 | sedan | 2006–2010 | R2 | €5,200 | 17% |
| 325d M57 | E91 | wagon | 2006–2010 | R2 | €5,500 | 16% |
| 325d M57 | E92 | coupe | 2006–2010 | R2 | €6,000 | 15% |
| 330d M57 | E90 | sedan | 2005–2008 | R2 | €5,950 | 15% |
| 330d M57 | E91 | wagon | 2005–2008 | R2 | €6,300 | 14% |
| 330d M57 | E92 | coupe | 2006–2008 | R2 | €6,850 | 13% |
| 330d M57 | E93 | convertible | 2007–2008 | R2 | €6,700 | 13% |
| 335d M57 | E90 | sedan | 2006–2010 | R3 | €6,900 | 13% |
| 335d M57 | E92 | coupe | 2006–2010 | R3 | €7,950 | 11% |
The last column is the point. The same repair is an inconvenience on one variant and a reason to scrap the car on another. A failure costing a quarter of the vehicle's value changes the purchase decision regardless of how rare it is.