Jeep Cherokee: 2.8 CRD injector copper seal leak — "black death"

The 2.8 CRD diesel used in the KK Cherokee is well known for leaking injector copper seals. Combustion gases escape past the seal and bake diesel and soot into a hard tar around the injector, a condition owners call black death. Caught early it is a seal and clean; left long enough the injector seizes into the cylinder head and extraction can mean removing and repairing the head, which is the difference between a modest bill and a very large one. The tar is visible from above once you know what you are looking for, which makes this one of the more checkable faults on the car.

• Ticking, chuffing or puffing from the top of the engine that beats in time with the engine
• Black tarry crust visible around the base of an injector
• Diesel or exhaust smell in the engine bay or entering the cabin
• Rough running or harder starting when cold

1. 1

   Open the bonnet and, with a phone torch, look down at the top of the engine where the injectors enter the cylinder head — you are looking for a black, tarry, crusty build-up around the base of any injector.

2. 2

   Clean metal at all four is what you want.

3. 3

   Start the engine from cold with the bonnet up and listen for a rhythmic chuffing or ticking from the top of the engine that is louder than the general diesel clatter and beats in time with it; put your hand near (not on) the area to feel for puffs of gas.

4. 4

   Smell for diesel or exhaust fumes in the engine bay.

5. 5

   Ask whether injectors have ever been out and whether new copper seals were fitted.

6. 6

   Check the service history for glow plug and injector work.

7. 7

   If a workshop inspection is possible: have a compression or leak check done and the injectors inspected properly, as a seized injector completely changes the cost of ownership.

Parts involved: Fuel injector.

$800 to $6,000 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.

• “Have the injectors ever been removed, and were new copper seals fitted?”
• “Is there any ticking or chuffing from the engine when cold?”
• “Has the cylinder head ever been off?”

The failure described above is documented in published sources — owner forums, technical service bulletins, recall notices and workshop write-ups — held in our fault database. The inspection instructions and the cost estimate are KickTyres’ own interpretation of them, and it is a starting point for an inspection rather than a manufacturer statement.