vinkodex.M57 (early): metal swirl flap can break off and enter the cylinder
It does not show up on every car. Check before you buy.
critical
severity
not available
mileage
2
sources
2 sources next to the write-up.
The fault
How you spot it
Swirl flaps sit in the intake ports of the six cylinder M57 diesel: at part load they spin the incoming air, saving fuel and emissions. According to the German technical press these flaps were made of metal on the engine versions before the technical revisions (TU and TU2), and sustained use can break the mechanism.
That is how it becomes engine damage: the detached flap travels down the intake port into the combustion chamber, and destroys the piston and the cylinder head there. That is not a repair but an engine rebuild.
Not every M57 has swirl flaps. Fitment depends on the model year, the gearbox and the emissions standard. Since the first revision (TU) the mechanism is plastic and more reliable, so this applies to the early engines from before that revision.
Which model
Who it affects
The card opens the generation, the engine or the transmission.
Engines and transmissions
Engine
M57D30
vinkodex.Checklist
M57 (early): metal swirl flap can break off and enter the cylinder
What you would check for this fault. Take it to the car.
Before you buy
Checklist
What you tick stays on this device only.
Sources
How we know
Information, not an expert opinion
We write the descriptions, and we put the source next to them. A person reviews them before they go out. They are still information, not a technical expert opinion.
- A fault on the list does not mean the car you are looking at has it.
- A fault missing from the list does not mean the model is fault-free. Write-ups are made model by model. Not all of them are done.
- You decide whether to buy. This is no substitute for an inspection. That needs a workshop and a history check.