BMW 5 Series: N20 timing chain guide failure (520i / 528i)
N20 timing chain guide failure (520i / 528i) is a common engine fault on the BMW 5 Series on the 2010–2017 cars, and we rate it critical. Putting it right costs $2,500 to $5,000 at New Zealand independent workshop rates. Below is what goes wrong, the symptoms to notice on a test drive, where to look, and what to ask the seller before you hand over any money. It is one of 58 documented faults on the BMW 5 Series.
- Vehicle
- BMW 5 Series
- Engine
- N20
- Years
- 2010–2017
- Fuel
- petrol
- System
- Engine
What you are looking at
Example of the part — not this vehicleThe front of a twin-cam engine with the timing cover off — chain, sprockets and guides.
What goes wrong
F10 520i/528i cars use the N20 four-cylinder turbo, whose plastic timing chain guides (on engines built before ~2015) go brittle and break, letting the chain wear and eventually skip - which bends valves and can destroy the engine. A tell-tale whine or rattle from the front precedes failure. BMW extended warranties overseas, but those have expired. This is the defining check on an F10 four-cylinder petrol.
What you would notice
- Whining or whirring from the front of the engine
- Rattle on cold start
- Timing/camshaft correlation fault codes
- Rough running or sudden failure
How to check it
Where to look. Timing chain and guides at the front of the engine
On a cold start listen for a rattle and, on the drive, a whine from the timing end. Ask whether the timing chain and guides have been replaced (a proven chain job is a big plus) and note the engine build date. Any correlation fault code is a serious warning.
What it costs to put right
$2,500 to $5,000 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “Has the N20 timing chain and guides been replaced?”
- “Is there any whine or rattle from the engine?”
Now check the BMW 5 Series you are actually looking at
Everything above is true of the model, and it is free. What it does not tell you is whether THIS car has been looked after: its odometer history and whether the reading has ever gone backwards, whether there is still money owing on it, whether it has been reported stolen, how many owners it has had and what it is really worth today. That comes from the official records for that plate. Enter the plate for the free details, or get the full history and a market valuation from $13.49.
Where this comes from
- Noorhan / Motronix N20 timing chain guides
- BimmerFest 'N20 Timing Chain Failure 528i' megathread
- Stedmans Garage BMW timing chain issues
BMW 5 Series buyer questions
Is n20 timing chain guide failure (520i / 528i) serious on a BMW 5 Series?
We rate it critical and common on the BMW 5 Series. F10 520i/528i cars use the N20 four-cylinder turbo, whose plastic timing chain guides (on engines built before ~2015) go brittle and break, letting the chain wear and eventually skip - which bends valves and can destroy the engine. A tell-tale whine or rattle from the front precedes failure. BMW extended warranties overseas, but those have expired. This is the defining check on an F10 four-cylinder petrol.
How much does it cost to fix on a BMW 5 Series?
$2,500 to $5,000 at New Zealand independent workshop rates. That figure is for this job on its own. A car showing the symptoms on this page is usually worth either walking away from or negotiating down by at least the repair figure.
Which BMW 5 Series years are affected?
Our research records this fault on the 2010–2017 BMW 5 Series. Build dates move around, especially on imported cars, so treat the range as the years to look hardest at rather than a guarantee either way. The official records tell you the exact build and first registration date for the car in front of you.
How do I check for it before I buy?
On a cold start listen for a rattle and, on the drive, a whine from the timing end. Ask whether the timing chain and guides have been replaced (a proven chain job is a big plus) and note the engine build date. Any correlation fault code is a serious warning. Look here: Timing chain and guides at the front of the engine