[beastlysun]

Hello all

Recently my car (F10 523i 2011) is a bit sick and needs a lot of antention. The BIG issue is low pressure in high pressure rail. Under 140bar to be exact.
It is N53B30A engine and i know about issues with HPFP, but i realy hope it is not the case for me. Mostly when i search around there are much more severe issues than my car developed

Here are some points from last 1-2 months

-car starts OK when cold, but occasionally i get a little bit longer crank time (less tha 2sec) when engine gets hotter (70 celsius and above)
-no problem when engine is cold
-no problem in sport mode (pressure still drops realy low, but no error
-idle is a tiny bit shaky, but rev stands still without drops
-hpfp pressure test OK and holds pressure without any issues
-checked all injectors, one was dead (leak) other were cleaned and tested OK
-can accelerate with cruise control without issues
-if i dont accelerate too much (stay bellow 25% throttle, or accelerate in short taps) no errors

situation when error occurs:
-oil temp above 90
-transmision in normal mode
-press and hold accelerator above ~25% for more than 10-15sec

after drivetrain error pops up:
-cooling spools upt to 100% cooling down the engine deeply below 90 degrees celsius
-LPFP goes to 100% PWM
-slight increase in consumption
-ride quality unchanged (acceleration is as before)

Last resort for me is HPFP. At least from my (small) knowledge. Any help would be realy helpfull

[HotSpicyChicken90]

Do you have ISTA?

[beastlysun]

Yes, this was sorted when that HPFP refused to go any further and had to be replaced. Issues gone from that time