BMW 3 Series: N55 3.0 turbo electric water pump sudden failure and overheating (335i)
N55 3.0 turbo electric water pump sudden failure and overheating (335i) is a common cooling fault on the BMW 3 Series on the 2012–2015 cars, and we rate it major. Putting it right costs $1,200 to $2,200 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 88 documented faults on the BMW 3 Series.
- Vehicle
- BMW 3 Series
- Engine
- N55
- Years
- 2012–2015
- Fuel
- petrol
- System
- Cooling
What you are looking at
No photograph available
What goes wrong
The N55 3.0 turbo six in the F30 335i uses an electric water pump instead of a belt-driven one. The pump's electronics or impeller can fail suddenly, often with no warning, typically somewhere between 50,000 and 190,000 km. The engine then overheats quickly and the car warns of high temperature or reduced power. There is no recall, so many owners replace the pump and thermostat as a pair before it fails.
What you would notice
- Engine temperature warning on the dash
- Cooling fan roaring at full speed, even after switching off
- Reduced power warning
- Coolant smell or boiling after a drive
How to check it
Where to look. Front lower part of the engine, behind the drive belt area
Ask whether the water pump and thermostat have been replaced and ask for the invoice; on a car past 100,000 km an original pump is due. Start the car and watch the dash for any coolant temperature warning. After the test drive, open the bonnet and listen for the cooling fan running unusually hard, and check the coolant level in the expansion tank. If a workshop inspection is possible: have the fault memory read for water pump codes such as 2E81 to 2E85.
What it costs to put right
$1,200 to $2,200 at New Zealand independent workshop rates. That is for this job on its own, not for the car.
Ask the seller
- “Has the water pump been replaced, and when?”
- “Has the car ever overheated or shown a coolant warning?”
- “Was the thermostat done at the same time?”
Now check the BMW 3 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
BMW 3 Series buyer questions
Is n55 3.0 turbo electric water pump sudden failure and overheating (335i) serious on a BMW 3 Series?
We rate it major and common on the BMW 3 Series. The N55 3.0 turbo six in the F30 335i uses an electric water pump instead of a belt-driven one. The pump's electronics or impeller can fail suddenly, often with no warning, typically somewhere between 50,000 and 190,000 km. The engine then overheats quickly and the car warns of high temperature or reduced power. There is no recall, so many owners replace the pump and thermostat as a pair before it fails.
How much does it cost to fix on a BMW 3 Series?
$1,200 to $2,200 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 3 Series years are affected?
Our research records this fault on the 2012–2015 BMW 3 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?
Ask whether the water pump and thermostat have been replaced and ask for the invoice; on a car past 100,000 km an original pump is due. Start the car and watch the dash for any coolant temperature warning. After the test drive, open the bonnet and listen for the cooling fan running unusually hard, and check the coolant level in the expansion tank. If a workshop inspection is possible: have the fault memory read for water pump codes such as 2E81 to 2E85. Look here: Front lower part of the engine, behind the drive belt area