vinkodex.
Known fault

N52 / N55: aluminium bolts of the VANOS housing can loosen

Typically between 134,000 and 300,000 km. It does not show up on every car.

critical

severity

between 134,000 and 300,000 km

mileage

4

sources

4 sources next to the write-up.

The fault

How you spot it

Four aluminium bolts hold the housing of the variable valve timing (VANOS). On some six cylinder engines built between late 2009 and mid 2012 these bolts loosen over time, and can also break.

If the housing moves, the timing becomes imprecise: the engine runs roughly, loses power, can drop into limp mode, and rarely can stall. That is why the maker started a safety recall (NHTSA 23V-707).

The recall covers the N51 / N52K / N52T / N55 engines; Their codes are N52B25, N52B30 and N55B30. The repair is replacing the four bolts; if a bolt is already broken or loose, the whole VANOS unit has to be replaced.

"No recall letter arrived" is not enough: ask at the workshop whether the repair code 0011520700 appears in the history.

Which model

Who it affects

The card opens the generation, the engine or the transmission.

Engines and transmissions

Checklist

N52 / N55: aluminium bolts of the VANOS housing can loosen

What you would check for this fault. Take it to the car.

Before you buy

Checklist

What you tick stays on this device only.

vinkodex.com · Before you buy it, see what can go wrong.

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.
Details in the terms