BMW N13 and N47: Timing Chain, Oil Burning, and How Not to Go Broke on Repairs
The short version: The N13 (gasoline) and N47 (diesel) engines of 2011–2015 carry built-in defects: timing chain stretch and oil consumption. The chain can let go as early as 50,000–62,000 miles, and that means catastrophic engine damage. Oil use of up to a quart every 620 miles is your signal to act immediately. Regular diagnostics and the right maintenance keep the repair bill manageable.
The Problem
You bought a 2013 BMW with the N13 or N47. A year in, there’s a metallic knock on cold starts, and the oil level drops a quart every 620 miles. Sound familiar? That’s not bad luck — those are systemic defects baked into the design of these engines.
Symptoms
- Metallic knock or rattle on a cold start
- Oil consumption above half a quart per 620 miles
- Power loss and hesitation under acceleration
- Black smoke from the exhaust
- Blue or white smoke while the turbo is working
- Boost pressure and valve timing fault codes
Root Causes
On the N13 and N47, the timing chain is the main weak point. It can stretch as early as 50,000–62,000 miles. On a cold start, a worn chain rattles metallically for 2–5 seconds until oil pressure reaches the timing chain tensioner. A snapped chain means pistons meeting valves — and catastrophic engine damage.
Oil consumption on the N13 comes from coked-up piston rings or worn valve stem seals. The rings lose their mobility when oil changes are few and far between and the trips are short with no warm-up. The rubber valve stem seals harden from repeated overheating, and oil makes its way into the combustion chamber.
Injectors on the N47 fail because of poor fuel quality and normal wear on the injector nozzles. The turbocharger suffers from oil starvation, contaminated oil, and worn bearings.
The Fix
Timing Chain Diagnosis
- Show up in the morning, when the engine is fully cold
- Start it and listen at the front of the engine — any metallic knock should put you on alert
- Run an OBD scan — chain stretch often shows up as valve timing fault codes
Injector and Turbo Diagnosis
Injector failure symptoms: power loss, uneven running, black smoke, higher fuel consumption. A computer scan will show cylinder-specific fault codes.
Turbo trouble symptoms: power loss, blue or white smoke, boost pressure fault codes, a whistle or howl while it’s working.
Repair Cost
| Component | Cost |
|---|---|
| Replacing a single N47 injector | Relatively inexpensive |
| N47 timing chain replacement | A significant expense |
| N47 turbocharger repair | A significant expense |
| Full Phase 1 engine rebuild | The most expensive repair of all |
Prevention
- Change the oil every 6,000–9,000 miles, using only quality synthetic oils with BMW approvals
- Fuel up only at stations you trust — bad fuel kills injectors and the turbo
- Run a computer diagnostic at least every 6,000–9,000 miles
- Check the timing chain on a cold engine once a month, especially once mileage approaches 62,000 miles
Buyer’s Checklist
- Listen for timing chain noise on a cold start
- Demand full service records with repair entries
- Plug in a scan tool and pull the fault codes
- Check the oil itself: black, thick, and smelling burnt is a bad sign
- Look over the engine bay for leaks
- Ask whether the chain has been replaced, and with which kit
Phase 2 Comparison
The B38 (gasoline) and B48 (diesel) engines of 2015–2019 are significantly more reliable. The B48’s timing chain lasts 124,000–155,000 miles without trouble, and the oil consumption problem was engineered out. Phase 1 repairs can run serious money, while Phase 2 engines develop these problems far less often.
The Bottom Line
The N13 and N47 demand attention, but maintained properly, they’ll go the distance. What matters is catching the symptoms early: chain knock on a cold start and oil consumption above half a quart per 620 miles. Regular diagnostics every 6,000–9,000 miles and quality fuel are your insurance against a ruinous repair bill. And when you’re shopping for a used BMW with these engines, always check the cold start and the service history.