Why is my BMW X3 leaking coolant from the oil filter housing?

Short answer: X3 B48/B58 engines often leak coolant from the plastic oil filter housing. Catch the drip early and consider an aluminum housing so you are not paying the labor twice.

Symptom: Coolant level dropping, sweet smell, residue on the OFH, low-coolant warning, or a shop pointing at the plastic housing.

What to check first

1. Check coolant level weekly.
2. Look for dried coolant on/around the oil filter housing.
3. Do not ignore a low tank—B48/B58 engines hate overheating.
4. Ask the shop about aluminum housing while labor is open.

Likely causes

1. Cracked plastic oil filter housing. B48/B58 X3s use a plastic oil filter housing that can crack or warp and leak coolant. Owners often replace it with an aluminum housing while they are in there.
2. OFH gasket / oil cooler seals. Even without a cracked housing, gaskets and cooler seals can seep. Replace seals with the housing.
3. Related plastic coolant fittings nearby. While the intake is off, shops often replace brittle coolant flanges that fail next.

What it usually costs

Parts are moderate; labor is the bill because the housing sits under intake plumbing. Aluminum upgrade costs more upfront and can save a repeat job.

Is it safe to keep driving?

Do not drive with a low coolant warning. Overheating can destroy the engine.

DIY or shop?

Experienced DIY possible with good tools; most owners use an indie BMW shop.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists these recalls touching this area of the BMW X3: 21V598000 (2020-2020 model years, engine); 22V513000 (2022-2022 model years, fuel system, gasoline:fuel injection system:fuel rail); 25V636000 (2020-2022 model years, electrical system:starter assembly:relay); 26V056000 (2021-2023 model years, electrical system:starter assembly). Check your VIN at nhtsa.gov/recalls. If your car is part of this recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 75 keyword-matched complaints for BMW X3 2018–2024 (of 619 unique complaints queried, NHTSA complaints API by model year, queried 2026-11-07; keywords: oil filter, housing, coolant, leak, OFH). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 2019 X3 Coolant Leaks on Reddit r/BMWX3, a 2019 owner chased coolant leaks around the oil filter housing area.
• In 22 X3 Oil Filter Housing on Reddit r/BMWX3, a 2022 owner discussed OFH replacement.
• In PSA - always replace B48/58 OFH with aluminum ones on Reddit r/BmwTech, techs and owners urged aluminum housings.
• In B48/58 Oil Filter Housing on Reddit r/BmwTech, owners shared OFH leak experiences across B48/B58 cars.

Quick tip

If your X3 is losing coolant near the OFH, fix it before a road trip—and strongly consider aluminum while the car is open.

Vehicle focus: BMW X3 with B48/B58 roughly 2018-2024 (G01 generation).

Safety / mechanic note

Coolant loss can lead to sudden overheat. Verify with a mechanic.