BMW M340i problems
Light NHTSA footprint — 11 owner complaints. Either a clean record or thin data; we'll show what's there.
Above-average reliability for the segment. Few systemic issues on file.
Buyable on the data — keep up the usual maintenance and inspect normally.
- No systemic severe-failure pattern in the complaint record
- Reliability score 8.8/10 — above the segment average
Our read of the federal NHTSA complaint and recall record for this exact year and model — not a substitute for a pre-purchase inspection. How we score.
Buying a used 2021 BMW M340i? Check these first
Here's what this model is known to do — so you can inspect for it, price it in, or make the seller fix it before you sign.
What to inspect on this specific car
- engine — 6 owner reports · ~$3,100 to fix
- powertrain — 3 owner reports · tends to show around 4,000 mi · ~$2,500 to fix
Recalls to confirm are done
Run the VIN from the listing — no active recalls on this model right now, but confirm none were opened after this car was built.
Verdict for buyers: 8.8/10 model. The priciest documented failure is engine (~$3,100) — get the seller's service records for it or inspect closely. Otherwise an average-risk used buy at a fair price.
We tell you what this model is known for and what to inspect — a vehicle-history report tells you what this exact car has been through. Smart buyers get both.
See the full pre-purchase inspection checklist →Ask anything about your 2021 BMW M340i
A noise, a warning light, a repair quote, "should I buy this?" — get an answer grounded in this vehicle's actual NHTSA record, not generic advice.
Answers use this vehicle's NHTSA complaint & recall record — owner-reported and unverified, not a diagnosis. Verify anything safety-critical with a mechanic.
Top trouble spots 2 categories with 3+ complaints
What owners are saying recent NHTSA-filed complaints · verbatim
At approximately 20,000 miles, vehicle indicated excessively low oil. The dealer indicated oil level was excessively low but did not identify the problem,. The vehicle was filled and returned to owner. Within 1000 miles, the incident occurred again. Dealer replaced replaced…
At approximately 20,000 miles, vehicle indicated excessively low oil. The dealer indicated oil level was excessively low but did not identify the problem,. The vehicle was filled and returned to owner. Within 1000 miles, the incident occurred again. Dealer replaced replaced…
The contact owns a 2021 BMW M340I. The contact stated while driving various speeds, the vehicle independently shifted from reverse(R) to drive(D) to park(P). The contact stated that while driving approximately 10 MPH and attempting to stop the vehicle, the brake pedal was…
Started as low creaking noise coming from front left wheel. Slow speeds, over small bumps. Over time (one month), creaking noises became louder and more frequent. At that time, steering was starting to feel stiff when turning to the left. Taken to 2 BMW dealerships who said it…
Estimate your repair exposure
Drag to your current mileage. Numbers are derived from this vehicle's complaint history.
Common questions
Is the 2021 BMW M340i reliable?
Mostly yes. With a reliability score of 8.8 out of 10 based on 11 owner complaints filed with NHTSA, the 2021 BMW M340i is generally a sound vehicle. The areas to watch are listed in the top problem section above — most are budget items, not deal-breakers.
Should you avoid the 2021 BMW M340i?
On the NHTSA data, the 2021 BMW M340i does not need avoiding. Buyable on the data — keep up the usual maintenance and inspect normally. The record behind that call: No systemic severe-failure pattern in the complaint record; Reliability score 8.8/10 — above the segment average. This is our read of the federal complaint and recall data — not a substitute for a pre-purchase inspection.
What should I check before buying a used 2021 BMW M340i?
Inspect the engine first — it's the most-reported issue on this model, with 6 owner complaints filed. Average repair cost runs about $3,100 at an independent shop. Also confirm any open recalls have been completed by running the VIN, and ask for service records covering the problem areas listed above.
Is the 2021 BMW M340i a good used car to buy?
It scores 8.8 out of 10 on our NHTSA-based read of 11 owner complaints. The main thing to watch is engine. Priced fairly and clean on inspection, it's a reasonable used buy. Our data covers what this model is known for — pair it with a vehicle-history report on the VIN to see what that specific car has been through.
What's the most common problem on the 2021 BMW M340i?
Based on NHTSA records, the most-reported issue is engine, with 6 complaints filed. Average repair cost runs about $3,100 at an independent shop.
What's the most expensive thing that goes wrong?
The engine is one of the costlier repair items. Average repair cost runs about $3,100 at an independent shop. Catching early warning signs can sometimes extend life by 20–30,000 miles.
How do I check if my BMW M340i has open recalls?
Paste your VIN into the decoder at the top of this page. We pull live from NHTSA, so you'll see exactly which campaigns apply to your vehicle and whether the dealer has logged the fix. Recall repairs are always free regardless of mileage or warranty status.
Is an extended warranty worth it on a 2021 BMW M340i?
Math is straightforward: a quality service contract runs $1,800–3,500 over 3 years. With 11 complaints on file and the costliest repair averaging $3,100, one major failure more than pays for it. The catch is reading the contract — many providers exclude wear items and require pre-authorization, so cheaper plans are not always better value.