Long cranks, stumbling and limp mode on a 335i or 135i often point to the high-pressure fuel pump. What the job is and what owners paid out of warranty.
The high-pressure fuel pump (HPFP) is the part that takes fuel from the tank pump and squeezes it way up so the direct injectors can spray it straight into the cylinders. On the N54 especially, this pump got a bad reputation early on. BMW extended coverage on a lot of these pumps years ago, but most cars on the road now are well past any of that, so it's an out-of-pocket repair.
Signs of a weak HPFP
- Long crank before it starts, especially warm
- Hesitation or a stumble when you get on it
- "Engine malfunction, reduced power" message
- Fuel pressure related codes on a scan
One thing to know: a lot of these symptoms overlap with injectors, the low-pressure pump in the tank, and even coils. A good shop checks fuel pressure readings before throwing a pump at it. Ask them what they saw.
The job itself
The pump lives on the engine and is driven off the camshaft. It's a few lines, some electrical, the pump and a seal. The part is the expensive half. Labor isn't huge on most cars, and it's one of the easier "big" BMW repairs.
What owners paid
We only have two reports for this one so far, both from 2015, so they're older and thin. The dealer quote was higher than the range of indie quotes the same owner collected. If you've had this done in the last couple of years, please send us your number so the page gets more useful.
Ask about
- Whether the pump is new or a reman, and which revision
- Whether they verified low and high pressure fuel readings before diagnosing
- Software updates. Dealers will sometimes flash the DME at the same time