2021 BMW X3/X4 Engine Replacement for Crankcase Error
A manufacturer communication, NHTSA ID 10187473, indicates that certain 2021 BMW X3 and X4 vehicles may need a full engine replacement. This is due to a manufacturing error in the crankcase affecting the connecting rod bearings.
Also applies to
- BMW X4
- 2021
BMW has issued a manufacturer communication, NHTSA ID 10187473, addressing a significant engine concern for certain 2021 BMW X3 and X4 models. This communication highlights a critical manufacturing error within the engine's crankcase assembly. This specific issue directly affects the connecting rod bearings, which are vital components for engine operation.
This 2021 BMW X3 manufacturer_communication indicates that the defect is severe enough to warrant a full engine replacement rather than a repair of individual components. Owners of affected vehicles should be aware of this potential issue.
Symptoms
While the manufacturer communication does not explicitly list owner-perceivable symptoms, a manufacturing error affecting connecting rod bearings and requiring engine replacement typically manifests as severe engine problems. These could include unusual engine noises such as knocking or rattling, reduced engine performance, or the illumination of the check engine light. In severe cases, the engine may seize or fail completely.
Diagnosis
The root cause of this issue is identified as a manufacturing error in the crankcase. This suggests that the defect is inherent from production rather than developing over time due to wear or maintenance. Diagnosis would likely involve a thorough inspection by a BMW technician to confirm the presence of the crankcase manufacturing error and its impact on the connecting rod bearings.
Repair Procedure Summary
The prescribed remedy for this specific issue is a complete engine replacement. This means that the entire engine assembly will be removed from the vehicle and a new or remanufactured engine will be installed. This comprehensive approach is deemed necessary to fully resolve the crankcase manufacturing error and restore the vehicle's reliability and performance. This repair is detailed in the 2021 BMW X3 manufacturer_communication, NHTSA ID 10187473.
Owner Action
If you own a 2021 BMW X3 or X4, it is advisable to contact your authorized BMW dealership. They can check if your vehicle is among those affected by this manufacturer communication. If your vehicle is identified as having the crankcase manufacturing error, the dealership will be able to advise on the next steps for the engine replacement procedure.
Source: NHTSA ID 10187473
What BMW X3 owners report
Counted from the records in our database across 23 model years.
- 2,295
- Owner complaints
- 64
- Recalls
- 1,126
- Service bulletins
- 114
- Crashes reported
- 133
- Fires reported
- 118
- Injuries reported
The 2021 model year
113 complaints, the 8th most of 23 model years on file. Owners reported 5 crashes, 2 fires and 2 injuries for this year, which also has 10 recalls on file.
Engine, the system this article covers, accounts for 494 of 2,295 complaints (22%), including 23 for 2021.
Complaints by model year
| 2004 | 138 | |
|---|---|---|
| 2006 | 143 | |
| 2007 | 258 | |
| 2008 | 122 | |
| 2011 | 126 | |
| 2013 | 226 | |
| 2015 | 105 | |
| 2019 | 171 | |
| 2020 | 110 | |
| 2021 | 113 |
Most-reported systems
- Engine — 494
- Electrical System — 450
- Air Bags — 404
- Power Train — 247
- Seats — 218
Latest recalls for the 2021 model year
- 26V056000 — Electrical System (Jan 2026)
- 25V636000 — Electrical System (Sep 2025) — Park outside
- 24V764000 — Structure (Oct 2024)
Recent owner reports about engine
The engine mounts on my BMW X3 have failed. It is a known national issue with the car, it can be exacerbated by the star/stop feature. There are no warnings or recalls and the repair is several thousand dollara.
Read owner complaints →There is an open safety recall for the engine starter on this vehicle. I contacted the local BMW dealer on 7/10/26 to have the recall fixed they advised me that they cannot address the recall because BMW North America has not sent the parts out for them to do…
Complaints are owner reports filed with NHTSA. They are unverified, and counts depend on how many vehicles were sold, so they are not a failure rate.
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