Known-defect dossier · vanos · CC-BY-4.0

BMW N51, N52K, N52T and N55 petrol engines (2009-2012 builds): VANOS unit bolts can loosen, with internal oil leak and reduced-power mode

BMW has run safety recalls for the VANOS (variable camshaft timing) adjustment units of N51, N52K, N52T and N55 petrol engines: recall 14V-176 in the USA in 2014 and recall 23V-707 effective 23 October 2023 for cars built from 2 September 2009 to 12 July 2012. BMW states that the unit bolts can loosen and break and that the units can develop an internal oil leak, which can put the engine into a reduced-power safe mode and, in rare cases, stall it.

Dossier revision 1 · data updated 2026-10-13 · canon release 2026.10.1

Read this firstEach entry describes a known weak point of a model, engine or gearbox, based on published sources. It is not a statement about any individual car and not a diagnosis. An entry does not mean that a given car has the defect; the absence of an entry does not mean that a car is sound. Prevalence figures are estimates for the stated population and method, with their biases, and cannot be applied to a single car. The data is provided as is, without warranty (CC-BY-4.0, section 5); it is not a certified, mechanical or legal inspection. Naming a manufacturer or its product is not an assessment of that manufacturer; source links show where each fact comes from. To report an error, open an issue at github.com/ElgardeCom/elgarde or write to support@elgarde.com. We correct mistakes.

At a glance

Severity: Critical destruction of the engine or gearbox, a safety risk, or an active safety recall.
Severity follows the worst documented outcome, not the average case.
Safety-relevant: Yes: a documented failure mode involves loss of drive, braking, steering, airbags or fire while driving.
In the Elgarde checklist: Ordinary entry: it does not cap the verdict by itself.
Documented in: US, HK

Which cars this covers

Only BMW petrol cars with an N51, N52K, N52T or N55 engine built from September 2009 to July 2012 (BMW's 2023 recall window: 2 September 2009 to 12 July 2012). Other BMW engines, including the N54, are not covered by the sources used here. Cars with both VANOS units or the whole engine replaced on or after 1 September 2012 have compliant parts, according to BMW.

Models in scope

BMW 1 Series, BMW 3 Series, BMW 5 Series, BMW 6 Series, BMW 7 Series, BMW X1, BMW X3, BMW X5, BMW X6, BMW Z4

Conditions on top of the model

All of these must hold:
- Engine: BMW N51 inline-six petrol, BMW N52K inline-six petrol, BMW N52T inline-six petrol, BMW N55 inline-six petrol
- Production date: September 2009 to July 2012

Notes on scope

The 2014 US recall (14V-176) used the window September 2009 to November 2011; the 2023 recall (23V-707) widened it to 12 July 2012 and to model years 2010-2013; a Hong Kong recall (10001167) gives builds from 9 October 2009 to 14 June 2011 and also lists the 7 Series. The recalls are documented in the USA and Hong Kong; no RappelConso record was found on 13 October 2026, so the status in the EU is not confirmed by the sources used here. The earlier checklist wording (rattle and rough idle) is not supported by the BMW documents, which describe emergency mode and reduced power.

How to check whether a particular car is affected

Elgarde reads the conditions above and gives one of three answers for a car:

Applies: every condition is confirmed for the car.
Possible: at least one condition cannot be confirmed yet. The entry stays on the checklist, with a note on what to find out.
Not applicable: a condition is clearly not met (for example a manual gearbox on a DSG entry). The entry is left off the checklist.

What to look for, and where

Model: one of the models listed above
The model name as on the registration document, e.g. Golf, 208, 320d.
Engine code: BMW N51 inline-six petrol, BMW N52K inline-six petrol, BMW N52T inline-six petrol, BMW N55 inline-six petrol
On the engine plate or block, or from a dealer VIN query. Displacement (P.1) and power in kW (P.2) on the registration certificate help narrow it down.
Production month: September 2009 to July 2012
The month the car was built (on the VIN plate or in the registration papers). It only matters when the year alone does not settle it.

When in doubt, treat the car as possible: asking one question too many costs less than missing a defect.

How the fault arises, as reported

According to BMW service bulletins, the VANOS adjustment units may develop an internal oil leakage that no longer lets the VANOS adjust quickly enough, so the engine emergency mode and engine malfunction stay permanently active. In the 2023 bulletin BMW states that the VANOS assembly bolts may, over time, loosen and eventually break; a reduced-power safe mode may then activate, the engine may not restart after being switched off and, in rare cases, the engine could stall. BMW's remedy replaces the bolts, or the whole VANOS assembly where bolts are loose or broken. A Hong Kong Transport Department notice describes the same bolting and an internal oil leak with lower oil pressure.

Reported symptoms

Early signs

Engine malfunction indication with the emergency mode permanently active

Later signs

Reduced engine power (safe mode)
Engine does not restart after switching off, or stalls (rare, per BMW)

What to check when inspecting a car

Documents and records. Confirm the engine (N51, N52K, N52T or N55) and the build date (door-pillar label or dealer VIN query) and whether it falls between September 2009 and July 2012.Red flag: Engine in the list and built in the window.
Documents and records. Ask a BMW dealer to check by VIN whether a VANOS bolt recall is open for the car (in the USA: 23V-707 and, for the earlier window, 14V-176; in Hong Kong: 10001167), and ask for proof it was completed. For 14V-176 BMW's bulletin says a campaign label with code 684 punched out on the B-pillar means it was done.Red flag: Recall open, or no proof it was done.
Documents and records. Ask for invoices of VANOS unit or engine replacement: according to BMW, cars with both VANOS units or a whole engine replaced on or after 1 September 2012 already have compliant parts.Red flag: In the window, recall open and no VANOS work on record.
Diagnostic read-out. Read the fault memory and test drive for an engine warning light or an emergency (reduced-power) mode.Red flag: Warning light or emergency mode: have a BMW specialist check the VANOS units before buying.

Repair and cost

Usual remedy: Replacement of the VANOS bolts; where bolts are loose or broken, replacement of the whole VANOS assembly on that side. If bolt heads are broken, the fragments must be retrieved from the engine first.
: No published repair cost is recorded in this dossier.

What the manufacturer and regulators have said

Manufacturer programme

US recalls 14V-176 (2014) and 23V-707 (BMW AG voluntary safety recall effective 23 October 2023) provide the repair free of charge. For 14V-176, NHTSA also records an extended warranty for about 170,172 model year 2010-2012 inline-six cars not covered by the recall, and BMW's 2023 bulletin refers to a VANOS limited warranty extension of 10 years / unlimited mileage (SI B01 10 14). Sources: [1], [4], [5]

Official records and rulings

Recall · NHTSA · NHTSA 14V176 · 2014-04-10
Official US recall: model year 2010-2012 BMW models whose VANOS housing bolts can loosen over time and may break, with reduced power or a stall; remedy: replace the four VANOS housing bolts on both units, free of charge; 156,137 vehicles. The record adds that about 170,172 model year 2010-2012 inline-six cars not covered by the recall receive an extended warranty for this condition. [1] api.nhtsa.gov
Technical service bulletin · BMW of North America (hosted by NHTSA) · SI B11 07 14 · 2014-10
BMW service bulletin: the VANOS adjustment units may develop an internal oil leakage that no longer lets the VANOS adjust quickly enough, so the engine emergency mode and engine malfunction stay permanently active. Applies to E70, E71, E82, E88, E89, E90, E92, E93, F10 and F25 with N51, N52K and N52T engines produced September 2009 to November 2011. Cars with both VANOS units or a whole engine replaced on or after 1 September 2012 already have compliant parts. [2] static.nhtsa.gov
Technical service bulletin · BMW of North America (hosted by NHTSA) · SI B11 08 14 · 2014-10
BMW service bulletin (October 2014 revision) for N55 engines produced September 2009 to November 2011 in E70, E71, E82, E88, E90, E92, E93, F07, F10, F10H, F12, F13 and F25: same internal oil leakage description; the remedy replaces the VANOS gear bolts, or the whole VANOS assembly where bolts are loose or broken; if bolt heads are broken the fragments must be retrieved from the engine. [3] static.nhtsa.gov
Recall · NHTSA · NHTSA 23V707 · 2023-10-20
Official US recall: 2010-2012 1 Series, 3 Series, 5 Series, X3, X5 and Z4 whose aluminium VANOS housing bolts can loosen over time and possibly break, causing a stall; remedy: dealers replace the four VANOS bolts free of charge; 157,796 vehicles. Owner letters were mailed 19 June 2024. [4] api.nhtsa.gov
Technical service bulletin · BMW of North America (hosted by NHTSA) · SI B11 09 23 · 2024-10-23
BMW bulletin: BMW AG voluntary safety recall effective 23 October 2023 for model year 2010-2013 cars produced 2 September 2009 to 12 July 2012 with N51, N52K, N52T and N55 engines (E60, E70, E82, E83, E84, E88, E89, E90, E91, E92, E93, F10, F25). The VANOS bolts may loosen and break; a reduced-power safe mode may activate, the engine may not restart, and in rare cases it could stall. The bulletin notes these cars had coverage under a limited warranty extension of 10 years / unlimited mileage (SI B01 10 14). Cars with both VANOS units or a whole engine replaced on or after 1 September 2012 are unaffected. [5] static.nhtsa.gov
Recall · Transport Department, Hong Kong · HK TD 10001167 · 2023-10-20
Official recall: BMW 1, 3, 5, 6, 7 Series, X3, X5, X6 and Z4 with N51, N52 and N55 engines built 9 October 2009 to 14 June 2011. The bolting on the VANOS adjuster housing might come loose or, in rare cases, break; the adjusters can develop an internal oil leak and, with lower oil pressure, coasting while driving or engine damage cannot be ruled out. Remedy: renew the bolting. Applies only to the listed vehicle identification numbers; launched 20 October 2023. [6] td.gov.hk

A recall or campaign record describes the vehicles in its scope, not a confirmed failure in any given car.

How common is it?

Recall population

This counts vehicles in the scope of a recall. It is not a failure rate.

Figure

156,137

Population

Model year 2010-2012 BMW vehicles in the US recall 14V-176 (VANOS housing bolts)

Geography

What was counted

Vehicles recalled

Confidence grade

C: manufacturer, recall or large-survey figure; method only partly known

Caveats

A recall population counts vehicles in scope, not failures. It is not a failure rate.

Sources

[1]

Recall population

This counts vehicles in the scope of a recall. It is not a failure rate.

Figure

157,796

Population

Model year 2010-2012 BMW vehicles in the US recall 23V-707 (VANOS aluminium bolts)

Geography

What was counted

Vehicles recalled

Confidence grade

C: manufacturer, recall or large-survey figure; method only partly known

Caveats

A recall population counts vehicles in scope, not failures. It is not a failure rate.
The 2023 recall overlaps the 2014 one in scope, so the two counts must not be added together.

Sources

[4]

Recall population

This counts vehicles in the scope of a recall. It is not a failure rate.

Figure

170,172

Population

Model year 2010-2012 BMW inline-six cars not covered by recall 14V-176 that received a warranty extension for the same condition, per the NHTSA record

Geography

What was counted

Vehicles covered by a warranty extension

Confidence grade

C: manufacturer, recall or large-survey figure; method only partly known

Caveats

The number counts vehicles in scope of a warranty extension, not failures. It is not a failure rate.

Sources

[1]

No reliable figure

No reliable figure for how many cars are affected is recorded for this entry. This is stated on purpose: a missing number is not a low number.

No verified share of affected engines with loosened or broken VANOS bolts has been published. The recall counts above are vehicles in scope, not failures. Sources: [1], [4]

Evidence and sources

Each statement above traces to the sources below. Review status is shown for every source.

Publisher	Title	Date	Type	Tier	Confidence	Links	Review
NHTSA	[1] Recall 14V176 - BMW, VANOS housing bolts NHTSA 14V176 Official US recall: model year 2010-2012 BMW models whose VANOS housing bolts can loosen over time and may break, with reduced power or a stall; remedy: replace the four VANOS housing bolts on both units, free of charge; 156,137 vehicles. The record adds that about 170,172 model year 2010-2012 inline-six cars not covered by the recall receive an extended warranty for this condition.	2014-04-10	Recall	1 · primary source	high	api.nhtsa.gov opened 2026-10-13 Archive copy	automated source check 2026-10-13
BMW of North America (hosted by NHTSA)	[2] SI B11 07 14 (October 2014 revision) - Recall Campaign 14V-176: N51, N52K and N52T Engine - Replace VANOS Gear Bolts SI B11 07 14 BMW service bulletin: the VANOS adjustment units may develop an internal oil leakage that no longer lets the VANOS adjust quickly enough, so the engine emergency mode and engine malfunction stay permanently active. Applies to E70, E71, E82, E88, E89, E90, E92, E93, F10 and F25 with N51, N52K and N52T engines produced September 2009 to November 2011. Cars with both VANOS units or a whole engine replaced on or after 1 September 2012 already have compliant parts.	2014-10	Technical service bulletin	1 · primary source	high	static.nhtsa.gov opened 2026-10-13 Archive copy	automated source check 2026-10-13
BMW of North America (hosted by NHTSA)	[3] SI B11 08 14 - Recall Campaign 14V-176: N55 Engine - Replace VANOS Gear Bolts SI B11 08 14 BMW service bulletin (October 2014 revision) for N55 engines produced September 2009 to November 2011 in E70, E71, E82, E88, E90, E92, E93, F07, F10, F10H, F12, F13 and F25: same internal oil leakage description; the remedy replaces the VANOS gear bolts, or the whole VANOS assembly where bolts are loose or broken; if bolt heads are broken the fragments must be retrieved from the engine.	2014-10	Technical service bulletin	1 · primary source	high	static.nhtsa.gov opened 2026-10-13 Archive copy	automated source check 2026-10-13
NHTSA	[4] Recall 23V707 - BMW, VANOS unit aluminium bolts NHTSA 23V707 Official US recall: 2010-2012 1 Series, 3 Series, 5 Series, X3, X5 and Z4 whose aluminium VANOS housing bolts can loosen over time and possibly break, causing a stall; remedy: dealers replace the four VANOS bolts free of charge; 157,796 vehicles. Owner letters were mailed 19 June 2024.	2023-10-20	Recall	1 · primary source	high	api.nhtsa.gov opened 2026-10-13 Archive copy	automated source check 2026-10-13
BMW of North America (hosted by NHTSA)	[5] SIB 11 09 23 - Recall 23V-707: Replace VANOS Adjustment Unit Screws (Revision 6) SI B11 09 23 BMW bulletin: BMW AG voluntary safety recall effective 23 October 2023 for model year 2010-2013 cars produced 2 September 2009 to 12 July 2012 with N51, N52K, N52T and N55 engines (E60, E70, E82, E83, E84, E88, E89, E90, E91, E92, E93, F10, F25). The VANOS bolts may loosen and break; a reduced-power safe mode may activate, the engine may not restart, and in rare cases it could stall. The bulletin notes these cars had coverage under a limited warranty extension of 10 years / unlimited mileage (SI B01 10 14). Cars with both VANOS units or a whole engine replaced on or after 1 September 2012 are unaffected.	2024-10-23	Technical service bulletin	1 · primary source	high	static.nhtsa.gov opened 2026-10-13 Archive copy	automated source check 2026-10-13
Transport Department, Hong Kong	[6] Recall 10001167 - BMW, bolting of VANOS adjuster HK TD 10001167 Official recall: BMW 1, 3, 5, 6, 7 Series, X3, X5, X6 and Z4 with N51, N52 and N55 engines built 9 October 2009 to 14 June 2011. The bolting on the VANOS adjuster housing might come loose or, in rare cases, break; the adjusters can develop an internal oil leak and, with lower oil pressure, coasting while driving or engine damage cannot be ruled out. Remedy: renew the bolting. Applies only to the listed vehicle identification numbers; launched 20 October 2023.	2023-10-20	Recall	1 · primary source	high	td.gov.hk opened 2026-10-13 Archive copy	automated source check 2026-10-13

Automated source check: the source was opened and its claims, dates and figures were compared with this dossier by an automated check. It is not a human sign-off.

Reuse, attribution and corrections

Text and data: Elgarde, licensed under CC-BY-4.0, canon release 2026.10.1. Credit “Elgarde”, link to this page and say if you changed the text.

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Suggested citation

Elgarde, “BMW N51, N52K, N52T and N55 petrol engines (2009-2012 builds): VANOS unit bolts can loosen, with internal oil leak and reduced-power mode”, known-defect dossier vanos, canon release 2026.10.1, CC-BY-4.0, https://elgarde.com/defects/vanos/

Machine-readable version

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Report a correction

Found a mistake, an outdated figure or a missing source? Open an issue at github.com/ElgardeCom/elgarde or write to support@elgarde.com. Mistakes are corrected.

Full disclaimerEach entry describes a known weak point of a model, engine or gearbox, based on published sources. It is not a statement about any individual car and not a diagnosis. An entry does not mean that a given car has the defect; the absence of an entry does not mean that a car is sound. Prevalence figures are estimates for the stated population and method, with their biases, and cannot be applied to a single car. The data is provided as is, without warranty (CC-BY-4.0, section 5); it is not a certified, mechanical or legal inspection. Naming a manufacturer or its product is not an assessment of that manufacturer; source links show where each fact comes from. To report an error, open an issue at github.com/ElgardeCom/elgarde or write to support@elgarde.com. We correct mistakes.