MajorCommonEngine

Mercedes-Benz Sprinter: Injector seat leaks — 'black death' carbon build-up

Injector seat leaks — 'black death' carbon build-up is a common engine fault on the Mercedes-Benz Sprinter on the 2000–2018 cars, and we rate it major. Putting it right costs $500 to $3,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 15 documented faults on the Mercedes-Benz Sprinter.

Vehicle: Mercedes-Benz Sprinter
Engine: 3.0L
Years: 2000–2018
Fuel: diesel
System: Engine

This page covers the Mercedes-Benz Sprinter as a model. Some faults only affect particular engines or build years — enter a plate below to narrow the list to one car.

All Mercedes-Benz Sprinter faults15 documented faults on this model

What you are looking at

What goes wrong

Sprinter CDI diesels (OM611/612/646/651 fours and OM642 V6) are the classic 'black death' engine: combustion gas leaks past the injector copper seals and bakes into a hard black tar around the injector, eventually seizing it into the head. Caught early it's a seal-and-clean job; left for years the injector must be machined out, or the head removed. The chuffing noise and diesel smell are unmistakable.

What you would notice

Chuff/tick noise from the engine top at idle
Strong diesel/exhaust smell under the bonnet
Black hard tar around injector bases
Sooty residue on the underside of the bonnet

How to check it

Where to look. Top of engine, injector wells under the acoustic cover

Remove or look under the engine cover and inspect every injector base with a torch — any black volcano-like crust means active leakage.
Listen at idle with the bonnet open for a rhythmic chuff.
Ask if injector seals have been replaced and when.

Parts involved: Fuel injector.

What it costs to put right

$500 to $3,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.

An estimate, in NZD, for the repair as normally carried out. What a specific car costs depends on which part has failed and what it damaged on the way — treat this as the floor for a negotiation, not a quote.

Ask the seller

“Have any injector seals been replaced — which cylinders?”
“Any diesel smell in the cab noticed?”

Now check the Mercedes-Benz Sprinter you are actually looking at

Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.

Not sure what you would be paying for? See what a full KickTyres check includes.

Where this comes from

The failure described above is documented in the sources below. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them.

Sprinter-source.com 'black death' megathreads
mercedesmedic.com injector black death guide
MBClub UK Sprinter CDI injector threads

Mercedes-Benz Sprinter buyer questions

Is injector seat leaks — 'black death' carbon build-up serious on a Mercedes-Benz Sprinter?

We rate it major and common on the Mercedes-Benz Sprinter. Sprinter CDI diesels (OM611/612/646/651 fours and OM642 V6) are the classic 'black death' engine: combustion gas leaks past the injector copper seals and bakes into a hard black tar around the injector, eventually seizing it into the head. Caught early it's a seal-and-clean job; left for years the injector must be machined out, or the head removed. The chuffing noise and diesel smell are unmistakable.

How much does it cost to fix on a Mercedes-Benz Sprinter?

$500 to $3,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.

Which Mercedes-Benz Sprinter years are affected?

Our research records this fault on the 2000–2018 Mercedes-Benz Sprinter. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.

How do I check for it before I buy?

Remove or look under the engine cover and inspect every injector base with a torch — any black volcano-like crust means active leakage. Listen at idle with the bonnet open for a rhythmic chuff. Ask if injector seals have been replaced and when. Look here: Top of engine, injector wells under the acoustic cover