The problem
This BMW came to us with the N47 2.0 litre diesel engine. The timing chain had snapped, and the chain guide was broken.
This is one of the most common problems on the N47 engine.
Why the N47 is different
On most engines, the timing chain is at the front. On the N47, BMW put the timing chain at the back of the engine, next to the gearbox.
This means the engine usually has to come out to replace the chain. That makes the job bigger than on many other cars.
What goes wrong
Over time, the plastic chain guides wear out and break. The chain gets loose and stretches. In the end, the chain can jump or snap.
The N47 is an interference engine. When the chain snaps, the valves can hit the pistons. In this engine, we found broken rocker arms, which shows how hard the parts hit each other.
Warning signs
- A rattling or whining noise from the back of the engine
- The noise is louder at idle or on cold start
- Engine warning light with timing faults
- The engine suddenly stops and will not restart
If you hear a rattle from the gearbox end of the engine, get it checked quickly. Catching it early can save the engine.
Which BMWs have the N47 engine?
The N47 is found in many diesel models, including the 118d, 120d, 318d, 320d, 520d, X1 and X3 diesel models.
What we did
- Removed the broken chain, guides and damaged parts
- Inspected the camshafts, camshaft carrier, valves and cylinder head for damage
- Fitted a new timing chain kit, guides and tensioner
- Replaced the broken rocker arms
The result
The engine is running smoothly again with a new timing chain system.
Prevention tips
- Don’t ignore a rattle from the back of the engine
- Change the engine oil on time, with the correct BMW-approved oil
- Use good quality oil filters
- If you are buying a used N47 diesel, ask if the timing chain has been replaced
How we can help
At WA Auto Service Center in Bibra Lake, we specialise in BMW. If your BMW diesel has a rattle or timing chain fault, book an inspection with us today.
