BMW/PSA 1.6 THP and VTi "Prince" (N14, N18, EP6): common problems by mileage
The "Prince" 1.6 petrol engine was developed by BMW and PSA and fitted from 2006 to Minis, Peugeots, Citroëns and DS models, and as the N13 to BMW's 1 and 3 Series. The turbo versions (Mini Cooper S, Peugeot/Citroën THP) are the troublesome ones: timing chain, oil consumption with carbon build-up, the high-pressure fuel pump and coolant leaks.
Updated · written by ipacen from documented workshop experience
- Engine codes
- BMW/Mini: N12, N14, N16, N18, N13; PSA: EP6, EP6C (VTi), EP6DT, EP6DTS, EP6CDT, EP6CDTX (THP)
- Displacement
- 1,598 cc
- Power
- 72–160 kW (98–218 hp)
- Built
- 2006–2018
- Timing drive
- Chain
- Fuel system
- Direct injection with turbo (THP, Cooper S, N13) or port injection with variable valve lift (VTi, One, Cooper)
Problems at a glance
| Problem | Typical mileage |
|---|---|
| Timing chain stretch, tensioner and guides high severity | 60,000–160,000 km 35,000–100,000 miles |
| Oil consumption and carbon build-up medium severity | 60,000–160,000 km 35,000–100,000 miles |
| High-pressure fuel pump wear (turbo engines) medium severity | 80,000–180,000 km 50,000–110,000 miles |
| Coolant leaks: water pump and thermostat housing medium severity | 60,000–150,000 km 35,000–95,000 miles |
Timing chain stretch, tensioner and guides
Symptoms
- Rattle on a cold start, later also at idle
- Camshaft timing fault codes and engine warning light
- Rough idle and loss of power
- If it jumps: no start and valve damage
Fault codes
Why it happens
Early turbo engines (about 2006–2011) had a weak tensioner and guides, and a low oil level from oil consumption makes it worse. Revised parts and an improved tensioner were introduced.
How to confirm it
- Listen on a cold start.
- Read camshaft timing (VANOS/VVT) deviation in live data.
- With the cam cover off, check chain slack and tensioner extension; the service information gives the check with the locking tools.
The fix
Complete chain kit: chain, latest tensioner, guides and sprockets where worn. Check the camshaft adjusters and set the timing with the locking tools.
Prevention
Check the oil level often; these engines use oil and run the chain dry when low.
Oil consumption and carbon build-up
Symptoms
- Oil level dropping between services
- Misfire when cold, rough idle
- Loss of power and economy
- Coked turbo oil feed line
Fault codes
Why it happens
Valve stem seals and rings let oil through, and the crankcase breather sends oil vapour into the intake. With direct injection nothing washes the intake valves, so carbon builds up; the turbo oil feed line can coke up too.
How to confirm it
- Oil consumption test over 1,000 km.
- Borescope the intake valves.
- Compression and leak-down test; check the crankcase breather.
The fix
Walnut-shell blasting of the intake valves, a new breather/oil separator, and valve stem seals or rings if consumption is high. Replace a coked turbo oil feed line.
High-pressure fuel pump wear (turbo engines)
Symptoms
- Long cranking, especially when warm
- Hesitation or loss of power under load
- Low fuel pressure fault code
- Fuel smell from a leaking pump
Fault codes
Why it happens
The camshaft-driven pump wears internally and can no longer hold pressure under load. A weak in-tank pump gives the same symptoms.
How to confirm it
- Log low-pressure and high-pressure fuel readings, specified against actual, under load.
- Check the low-pressure supply (in-tank pump, filter) first.
- Inspect the pump's drive (cam lobe and follower) when it comes off.
The fix
Replace the high-pressure pump (and the follower if worn), then clear adaptations and road-test with fuel pressure logged.
Coolant leaks: water pump and thermostat housing
Symptoms
- Coolant level dropping, crusty deposits under the pump or housing
- Sweet smell after a drive
- Temperature warning in the worst case
Fault codes
Why it happens
The plastic thermostat housing cracks and the water pump seal leaks with age and heat cycles.
How to confirm it
- Pressure-test the cooling system and look for traces at the pump and thermostat housing.
- Check that the engine reaches operating temperature (thermostat).
The fix
Replace the leaking part (often pump and thermostat housing together) and bleed the system as the service information describes.
Known-good values
Add readings from a healthy 1.6 THP/PrinceReadings from 1.6 THP/Prince engines that run correctly, reported by mechanics on ipacen. Each member counts once; the median shows from 3 members up, with the middle half of the readings as the range. No readings yet: be the first.
See the values you can report and the typical guide
| Value | Typical guide | Measured by members |
|---|---|---|
| Engine | ||
| Idle speed, warm (rpm) | Usually about 650–900 rpm | — |
| Coolant temperature, fully warm (°C) | About 85–105 °C | — |
| Oil pressure, hot idle (bar) | Typically above about 1.0 bar | — |
| Oil pressure, hot, 2,000 rpm (bar) | Typically above about 2.5 bar | — |
| Compression, typical cylinder (bar) | Petrol about 11–15 bar, diesel about 25–35 bar | — |
| Air and fuel | ||
| Air mass, warm idle (g/s) | Petrol: roughly 1 g/s per litre of engine size | — |
| Total fuel trim, warm idle (%) | Within about ±10 % | — |
| Total fuel trim, 2,500 rpm (%) | Within about ±10 % | — |
| Manifold pressure, warm idle (kPa) | Naturally aspirated: about 25–40 kPa | — |
| Boost at full load (absolute) (mbar) | Turbo engines: compare with specified boost | — |
| Fuel system | ||
| Injector pulse width, warm idle (ms) | Port injection: often about 2–4 ms | — |
| Fuel pressure, low-pressure side, idle (bar) | Check the specification for the system | — |
| Rail pressure, warm idle (bar) | Diesel common rail: typically about 250–400 bar | — |
| Electrical | ||
| Charging voltage, 2,000 rpm (V) | About 13.8–14.7 V | — |
| Lowest battery voltage while cranking (V) | Above about 9.6 V | — |
| Crankshaft sensor resistance (inductive type) (Ω) | About 200–2,000 Ω | — |
| Injector resistance (petrol port injection) (Ω) | High-impedance: about 11–18 Ω | — |
The guide is ipacen's typical range, not manufacturer data. Member values are what colleagues measured on healthy cars; always compare with the specification for the engine.
Which cars have the 1.6 THP/Prince
Cases with this engine
Share yoursNo published cases matched to this engine yet. Fixed one of these problems? Share the case with the measurements that proved it.
1.6 THP/Prince: questions and answers
What are the most common problems with the 1.6 THP/Prince?
The most reported are timing chain stretch, tensioner and guides; oil consumption and carbon build-up; high-pressure fuel pump wear (turbo engines); coolant leaks: water pump and thermostat housing. Each one is described below with its symptoms, fault codes, how to confirm it and the usual fix.
At what mileage does the 1.6 THP/Prince have timing chain stretch, tensioner and guides?
Typically between 60,000–160,000 km (35,000–100,000 miles), depending on use and maintenance. Early turbo engines (about 2006–2011) had a weak tensioner and guides, and a low oil level from oil consumption makes it worse. Revised parts and an improved tensioner were introduced.
At what mileage does the 1.6 THP/Prince have oil consumption and carbon build-up?
Typically between 60,000–160,000 km (35,000–100,000 miles), depending on use and maintenance. Valve stem seals and rings let oil through, and the crankcase breather sends oil vapour into the intake. With direct injection nothing washes the intake valves, so carbon builds up; the turbo oil feed line can coke up too.
At what mileage does the 1.6 THP/Prince have high-pressure fuel pump wear (turbo engines)?
Typically between 80,000–180,000 km (50,000–110,000 miles), depending on use and maintenance. The camshaft-driven pump wears internally and can no longer hold pressure under load. A weak in-tank pump gives the same symptoms.
At what mileage does the 1.6 THP/Prince have coolant leaks: water pump and thermostat housing?
Typically between 60,000–150,000 km (35,000–95,000 miles), depending on use and maintenance. The plastic thermostat housing cracks and the water pump seal leaks with age and heat cycles.
Which cars have the 1.6 THP/Prince engine?
Mini: One, Cooper and Cooper S (R55 to R61). BMW: 1 Series (F20, F21) 114i, 116i, 118i; 3 Series (F30) 316i. Peugeot: 207, 208 (incl. GTi), 2008, 308, 3008, 5008, 508, RCZ. Citroën: C4, C4 Picasso, C5, DS3, DS4, DS5. DS: DS 3, DS 4, DS 5.
Mileage windows are typical workshop experience, not manufacturer data. Engines vary by version, use and maintenance; always follow the service information for the vehicle.