Which B48 repairs are worth doing before they fail?
Enter your VIN. We check whether it likely has the B46/B48 2.0L turbo four, whether it's in the group where cooling leaks cluster, whether the free vent-line action and the starter recalls (25V-636 and 26V-056) may cover it, and list every NHTSA recall for your model.
Illustration, not to scale. Source badges are explained in Weak parts.
Starter recalls (fire risk): 25V-636 · 26V-056. NHTSA's 25V-636 record: "Owners are advised to park their vehicles outside and away from structures until the remedy is complete." Certain 2019–2024 30i cars and GR Supras. Free vent line on many F-series cars. Check your VIN at NHTSA
Recall details & sources
Covers 230i · 330i · 430i · 530i · X3 30i · X4 30i · Z4 sDrive30i · X1 / X2 28i · 228i / M235i Gran Coupe · X1 / X2 M35i · GR Supra 2.0 · MINI Cooper S / JCW (possibly). A 2012–2016 328i, 428i or X3 28i? See the N20 page. A six-cylinder 340i, M340i or X5 40i? See the B58 page.
~65k mi
Half of the 58 cooling-system failures that B46/B48 owners reported to NHTSA with a mileage came before about 65,000 miles. On 2017 rear-drive-based cars, 43% of complaints name a cooling part. Reported cases, not your car's odds. COMPUTED FROM NHTSA DATA
See the chart ↓Starter recalls 25V-636 and 26V-056 (fire risk; 25V-636: park outside until repaired) cover certain 2019–2024 30i cars and GR Supras. A free vent line and a 15-year EVAP extension apply to many earlier cars. Check by VIN. OFFICIAL
See the free fixes ↓Sums of range midpoints from each part's card (mixed sources: see the badges). Worst case, not an expected cost.
See the cost table ↓1,764
VIN-confirmed B46/B48 owner complaints filed with NHTSA (BMW 1,586, MINI 174, Toyota 4) NHTSA DATA
- 26% give a usable mileage
- Complaints pulled Oct 19, 2026
- Prices checked Oct 19–20, 2026
Built on NHTSA government data, plus clearly labeled bulletin, shop and owner sources
We pulled NHTSA owner complaints for every B46/B48 model name and kept only the ones whose VIN decodes to a B46/B48 car (BMW, MINI and the Toyota GR Supra 2.0). Plug-in hybrids are left out.
Source: NHTSA complaints API (pulled Oct 19, 2026) and NHTSA's bulk complaint file for mileage, VIN-checked with NHTSA's vPIC decoder. Counts come from keyword matches in owners' free-text complaints; they are self-reported, unverified and not adjusted for how many cars were sold. Younger cars have fewer miles, so later model years may catch up. See Method.
Cooling share by model year (table)
| Model year | Complaints | Name a cooling part | Share |
|---|---|---|---|
| 2017 | 95 | 41 | 43.2% |
| 2018 | 144 | 44 | 30.6% |
| 2019 | 238 | 38 | 16.0% |
| 2020 | 146 | 13 | 8.9% |
| 2021 | 133 | 1 | 0.8% |
| 2022 | 91 | 2 | 2.2% |
| 2023 | 29 | 1 | 3.4% |
| 2024 | 64 | 0 | 0.0% |
| 2025 | 58 | 1 | 1.7% |
Free fixes to check first
The B48's best news: several of its known problems have free fixes. Recall repairs are free at dealers, and BMW has extended coverage or issued service actions on some parts. All of these depend on your VIN and build date, so check them before you pay for anything.
Service actions and extended coverage (not recalls)
- Coolant vent line: BMW SIB 17 01 21 (NHTSA copy) replaces it free on F22, F23, F30, F31, F32, F33, F34 and F36 cars built April 24, 2015 to September 24, 2019. See item 2. OFFICIAL
- EVAP purge valve: 15 years or 150,000 miles on many 2016–2019 cars (SIB 01 04 19, SIB 01 02 24, SIB 01 03 24, SIB 01 04 24). OFFICIAL
- Mechanical coolant pump: free replacement on some G20, G22, G23 and G30 cars built September 2020 to May 24, 2021 (SIB 11 05 21, per BimmerBench). See item 3. FORUM/BLOG
- MINI oil filter housing: MINI issued service actions for some 2014 Cooper S and Cooper builds (SI M11 01 14, M11 09 14, M11 05 15). Ask a MINI dealer by VIN. OFFICIAL
The 4 B48 parts owners and shops most often report failing
Tap a card or a numbered dot on the diagram at the top of the page; the violet dots are recall checks. Every figure has a badge for where it comes from: OFFICIAL (NHTSA or BMW documents), SHOP/RETAILER (retailer prices, published shop quotes and shop articles), FORUM/BLOG (owner forums, enthusiast blogs, quote sites that collect owner prices, and repair bills owners quoted in NHTSA complaints: real reports, but unverified), ESTIMATE (our estimate where no good public number exists) or COMPUTED FROM NHTSA DATA (our analysis of NHTSA's public complaint data). A figure with several sources shows the weakest one. On this page the "if it fails" figure is bills owners reported or shop and dealer quotes, as each card says. Retailer prices were checked Oct 19, 2026 and change often.
What it costs: fix early vs. after failure
Fix-early costs are independent-shop prices (parts and labor), using the midpoint of each range. The "if it fails" column is a reported range for repair bills, not a prediction for your car.
| # | Part / system | Reported failure range | Fix early | If it fails | Ratio |
|---|
Essentials = oil filter housing, vent line and water pump + thermostat, the cooling parts that cluster on 2017–2019 rear-drive-based cars. The vent line is free if BMW's service action applies to your VIN. Free recalls and service actions aren't in these sums. Cooling failures overlap (several end in the same overheat), so the "if every part fails" sum overstates real exposure. Dealer prices typically run higher. ESTIMATE
What to bundle (and why it saves labor)
Most of a B48 cooling repair is labor and a coolant drain, fill and bleed, so do the cooling parts in one visit.
Oil filter housing + vent line + pump
- Oil filter housing (genuine or aluminum)
- Coolant vent line (free if the service action applies)
- Water pump and heat management module, if original past ~60k
- Expansion tank and hoses
- Coolant flush and bleed
One drain, fill and bleed covers all of it, and the vent line is a small add-on once the housing job is open. ESTIMATE
Recalls + service actions
- Starter recalls 25V-636 / 26V-056, if open for your VIN
- Vent line SIB 17 01 21, if eligible
- EVAP purge valve extension, if it's failing
- Any other open recall on nhtsa.gov/recalls
Ask for every open campaign on your VIN in one visit. These are free at the dealer. OFFICIAL
A B48 report isn't available yet
Our planned $19 personalized ownership report covers N20 cars only, and its order form turns away other VINs. If enough B48 owners ask, we'll build a B48 version.
- Join the B48 list and we'll email you if a B48 report launches
- We take no payment and don't promise a launch date
- Every email has an unsubscribe link
Own an N20 (2.0L, 2012–2016) BMW too? See the planned N20 report.
Join the B48 list →Join the B48 list
We'll email B48 updates, including if a B48 report launches. No date is promised.
Why trust this? Our method in 60 seconds
1 · Government data, filtered by VIN
We pulled NHTSA owner complaints for every B46/B48 model name (BMW, MINI and the Toyota GR Supra 2.0), decoded each complaint's partial VIN with NHTSA's vPIC decoder and kept only real B46/B48 cars: 1,764 complaints, after leaving out plug-in hybrids. Mileage comes from NHTSA's bulk complaint file; 454 of the 1,764 have a usable mileage. Part counts come from keyword matches in owners' free-text complaints.
2 · Labeled sources
Recalls and BMW bulletins come from NHTSA (OFFICIAL). Part prices are retailer prices checked Oct 19, 2026, and shop prices come from BimmerBench and BimmerQuote, which collect owner and shop quotes, and from bills owners quoted in NHTSA complaints (FORUM/BLOG). Our statistics are COMPUTED FROM NHTSA DATA; anything we couldn't source is ESTIMATE.
3 · Honest about limits
These are reported ranges, not predictions or failure rates. Complaints are self-reported, younger cars have fewer miles, and only 4 complaints are Supra 2.0s, so Supra and MINI owners should treat the BMW figures as a guide only. Layout and generation are our estimates from model and year. Nothing here guarantees a part won't fail, and none of it replaces an inspection by a qualified technician.
Independence: we don't take money from shops or retailers for placement, and the retailer links on this page are not paid links. If any become paid (affiliate) links, each one will be labeled “Paid link” where it appears. Commissions would never change the numbers. Our recommendations are not influenced by affiliate commissions, and any future paid shop referrals will be disclosed.
B48 FAQ
Which cars have the B48 (or B46) engine?
In the US, the B46/B48 2.0L turbo four is in the 2017-on 230i, 330i, 430i and 530i, the 2018-on X3 30i (X3 30 xDrive from 2025), the 2019-on X4 30i and Z4 sDrive30i, the 2016-on X1 28i, the 2018-on X2, the 2020-on 228i and M235i Gran Coupe, the X1 and X2 M35i, the 2021–2024 Toyota GR Supra 2.0 and most 2014-on MINI Cooper S and John Cooper Works models. BMW uses the B46 name for some US versions; it's the same engine family. Watch out: the 2012–2016 328i, 428i, 228i and X3/X4 28i use the earlier N20; the 2014–2016 M235i uses the six-cylinder N55; a base MINI Cooper uses the three-cylinder B38; and plug-in hybrids (330e, 530e, X3 30e) aren't covered here. The VIN check above sorts this out for most cars.
Is there a recall for the oil filter housing?
No, not on BMW-branded cars in the US. The housing on 2017–2019 rear-drive-based cars is plastic with coolant passages, and it's the most common cooling complaint in our data. For later cars, BMW's SIB 11 10 25 (December 2025) gives a revised repair for a leak here; it's a repair procedure, not free coverage. MINI issued service actions for some 2014 Cooper S builds.
Am I owed a free coolant vent line?
Possibly. BMW's service action SIB 17 01 21 replaces the coolant vent line free on F22, F23, F30, F31, F32, F33, F34 and F36 cars (2, 3 and 4 Series) built April 24, 2015 to September 24, 2019. The G01 X3, G02 X4 and G30 530i aren't on its chassis list. Ask a BMW dealer to check your VIN; the build month is on the driver-side door-jamb label.
Which B48 cars are in the starter recalls?
Recall 25V-636 (September 2025) covers certain 2019–2021 330i, 2019–2022 Z4 sDrive30i, 2020–2022 530i, X3 30i, X4 30i and Toyota Supra, 2021–2022 430i and 2022 230i. NHTSA's record says: "Owners are advised to park their vehicles outside and away from structures until the remedy is complete." Recall 26V-056 (January 2026) covers certain 2021–2024 30i cars and 2021–2023 Supras. The remedy for both is a new starter, free at the dealer. Both cover certain cars by production date, so check your VIN at nhtsa.gov/recalls or with a dealer.
Does the B48 have the N20's timing-chain problem?
Not in the complaint data: none of the 1,764 VIN-confirmed B46/B48 complaints we found mention the timing chain. That describes reported complaints, not a guarantee, but it's the biggest difference from the N20. The B48's pattern is plastic cooling parts on 2017–2019 rear-drive-based cars.
How accurate are these repair costs?
They come from BimmerBench's national-average estimates, retailer part prices (checked Oct 19, 2026), quotes collected by BimmerQuote, and bills owners quoted in NHTSA complaints. Every figure is labeled by source type, as our Estimate, or as Computed from NHTSA data. Prices vary by region and shop; get a written quote before any work.
Will doing this work keep my engine from failing?
No one can promise that. Replacing known weak parts early can lower your exposure to some expensive failures, but parts can still fail, and other things can go wrong. The "if it fails" numbers are reported ranges for repair bills, not predictions.
Is there a B48 report?
Not yet. Our planned $19 ownership report covers N20 cars only, and its order form turns away other VINs, so please don't try to order it for a B48. Join the B48 list on this page and we'll email you if a B48 version launches. We take no payment and don't promise a date.
Do you store my VIN?
No. The VIN check runs in your browser and sends the VIN only to NHTSA's public vPIC decoder and recall API; we don't store or log it. (If you open a shared link that contains a VIN, our host, Cloudflare, receives that address as part of the request; the page then removes it from the address bar.) If you join the B48 list after a check, we save only the decoded model (for example "2019 BMW 330i") with your email and the fact that you signed up from the B48 page. We don't sell it, and we delete it on request. See the privacy policy.