BMW 2A87 means the 335i exhaust cam was late or did not reach its commanded position. On applicable N54 E9x cars, BMW's SIB prioritizes oil supply and the full ISTA test plan; it does not say to replace both solenoids from the code alone. Identify N54 versus N55, verify oil/filter/pressure, graph exhaust target versus actual, test its circuit and follow the engine-correct adjuster, passage and sealing-ring branch.
Match the symptom
Select the closest observation. The result changes the first test; it does not name a part to replace.
Check oil supply and correlation promptly.
What can set 2A87—and how to separate it
The order below is evidence-driven, not a universal probability ranking. Vehicle year, repair history, companion codes and the operating condition in freeze frame change where diagnosis should begin.
| Possible cause | Evidence that supports it | First useful test |
|---|---|---|
| Low, wrong or degraded engine oil | Level/specification and CVVT response are abnormal | Oil and filter audit |
| Affected cam oil-control valve or circuit | Command/current or loaded circuit fails | GDS/KDS actuation and circuit test |
| Restricted oil passage or sticking CVVT phaser | Safe pressure but commanded response fails | Hydraulic response test |
| Timing chain, tensioner or cam indexing fault | Stable phase offset, noise or mechanical evidence | Cam/crank waveform and timing inspection |
| Cam sensor/reluctor or ECM-input problem | Dropout, noise or companion circuit code | Signal and correlation test |
Measure exhaust response
Graph desired and actual exhaust angle at the temperature and load that caused reduced power.
Compare intake behavior under equal conditions to identify a shared oil issue without assuming both sides failed.
Test electrical and hydraulic paths
Load-test solenoid command and connector tension and use ISTA activation while watching cam movement.
Inspect oil condition and debris; a contaminated valve can indicate a broader oil-supply problem.
Verify a directed repair
Follow the exact N54 or N55 test plan for passages, adjuster and hook-ring seals rather than replacing by reputation.
Confirm repeatable hot response without 2A87 or 3100.
Save these scan-data clues
Freeze frame is a snapshot of conditions when the PCM matured the fault. It can distinguish an idle-only problem from a load, cold-start or monitor-completion problem. Clearing first throws that context away.
- Exact VIN, platform, model year and engine sales code
- All confirmed, pending and permanent companion codes
- RPM, load, coolant temperature and vehicle speed
- Relevant commanded and actual scan data
- Recent service, repairs and symptom conditions
- Manufacturer bulletin and current software/VIN status
A practical diagnostic workflow
- 01Identify engine and intake/exhaust cam
Engine families and CVVT coverage differ.
- 02Save desired/actual angles and companions
Record temperature, rpm, load and oil history.
- 03Verify oil, filter and mechanical pressure
Do not command CVVT with unsafe lubrication.
- 04Test the correct oil-control valve and circuit
Separate electrical command from hydraulic movement.
- 05Scope cam against crank
Distinguish dropout from a stable phase error.
- 06Inspect phaser and timing only as evidence directs
Avoid sensor or chain replacement by guess.
- 07Perform applicable learning and verify
Confirm commanded tracking and no pending code.
Do not replace the most commonly named component from 2A87 alone. Confirm the exact engine, preserve evidence and complete the manufacturer test sequence before ordering parts.
Why the model year changes the test
BMW 335i diagnostics divide primarily between twin-turbo N54 E9x cars, single-turbo N55 late-E9x/F30 cars and market-specific variants. The engines share a badge but not boost actuators, injectors, Valvetronic hardware or fault-code families. Confirm VIN, chassis, production date, engine, DME software and modifications before applying an N54 30FF or N55 2C57 procedure.
- 2A87 is exhaust VANOS; 2A82 is intake.
- N54 and N55 hardware, DME data and repair instructions differ.
- A consequential 3100 on N54 does not become the primary repair.
- Hot-only power reduction should be captured with scan data.
2A87 FAQ
Does the code prove the oil-control valve failed?+
No. Oil supply, wiring, passages, phaser, chain and feedback faults can produce it.
Can low oil cause it?+
Yes. CVVT depends on controlled engine-oil flow.
Can I drive?+
Limit driving and stop for rattle, oil warning, stalling or severe running problems.
Should I replace cam sensors?+
Not without waveform or circuit evidence.
Why check P0017?+
It can show that the exhaust cam is no longer correctly correlated with the crankshaft.
Does it prove the chain stretched?+
No. A stable measured offset and mechanical checks must support that conclusion.
Can cleaning the solenoid fix it?+
Only when contamination is confirmed and the approved service method permits it; the oil-system cause still matters.
What confirms repair?+
Desired and actual cam timing track correctly with no pending DTC.
Ford diagnostic references
These documents explain Ford monitor operation. Exact pinpoint tests, connector views and specifications must be selected for the truck's VIN and model year in current service information.
01BMW SIB 11 02 08 — 2A82/2A87 VANOS faultsIncludes defined E70 N52K and E9x N51/N52K/N54 groups; describes late cam response, oil supply and VANOS test-plan branches↗02BMW Technical Information SystemOfficial VIN-, engine- and ISTA test-plan information↗03BMW owner's manualsOfficial VIN/model operating, warning and maintenance information↗