Hpfp failure diy repair

Discussion in 'Audi TDI forums' started by greeceq5, Jul 7, 2017.

  1. greeceq5

    greeceq5 New Member

    Aug 10, 2014
    AUDI Q5 2008 TDI 170HP CAHA
    Hi guys
    I suffered the dreaded hpfp failure 10 days ago.
    I have a Q5 2.0 TDI CAHA 170HP with 260000km.
    Glow plug flashed while cruising on the highway went into limp mode, 15 km later stopped the car it went off and never restarted. Entire fuel system full of metal flakes.
    I decided to change the hpfp only.
    My old pump had a 03L130755 code. I went with a 03L130755D made in chech republic.
    Ok here is what I did.
    Keep everything as clean as possible with engine cleaning slray and blown compressed air before dismantling lines etc...
    1)remove old pump after removing timing belt (with locking tools etc)
    2) remove common rail. Clean it with gasoline (yes) and magnet after removing fuel pressure sensor only, flushed with gasoline and blow with compressed air. Did the same for the pipes to injectors.
    Blow compressed air to each injector feed and pray
    3) Followed the same procedure for all under the hood fuel lines, pipes and regulators
    4) removed in tank pump. Picked up with magnets most of the flakes. Emptied tank. Cleaned pump with gasoline and rugs and engine cleaning spray and compressed air over and over (4 hours meticulusly)....
    5) put in tank pump in a large open container, submersed in gasoline. Attached a pipe with an in line 5micron filter to the feed exit and put the end of the pipe at the bottom of the container. Put 2 large magnets at the bottom near the exit of this pipe. Hotwire the pump and let it work for 2 hours. The amount of metal debree caught in the filter and tge magnets was A LOT. Remove the filter and take a sample while hotwiring the pump in a clear bottle. I repeated sampling tgroughout the 2 hours 3 times until satisfied that crystal clear gasoline was in the bottle.
    6) repeat the same process as in 5 for the auxillary pump (in my car is under the car after the tank and before the fuel filter)
    7) clear (as in 2) pipes from tank to auxillary pump and from filter to engine bay, including pressure relief valve and from engine bay to tank. Put auxillary and in tank pump back together and connect all pipes and lines as they were originally.
    8) install new hpfp and double check timing belt.
    9) connect a pipe with in line filter to pipe going to the feed of the hpfp and guide the end to an empty container. Connect a pipe to the return line of the hpfp and guide the end to a 20lt canister filled with clean diesel fuel.
    10) put 40 liters of clean diesel to the tank.
    11) run tranfer fuel pump test in vcds and repeat until the clean diesel container is nearly empty (attach a battery charger) . Check with a clear bottle once in a while to make sure diesel is coming clean
    12) attach feed and return lines to hpfp
    13) pray the injectors where spared by the debree
    14) run vcds procedure a couple more times
    15) start the car while praying..... Ok!!!!!
    I let it run for 15 minutes in idle. Cleared all codes that come up from disconnecting varius stuff.. The car runs just fine ever since, no codes whatsoever,1500 km already on.
    I know it is still early but we will see how this goes.
    I am puzzled at how the injectors got spared. The funny thing is that I put new ones just 20000km ago due to white smoke and 2 of the old ones where stuck open so I tried to spare as much money as possible.
    My opinion is that since I had noticed 2 ocassional more difficult start ups (3sec crank time instead of 1) in the last 2 months, the flakes where there already and building up until the hpfp gave up and the car couldn't be started due to low common rail pressure. Mayby some design in the piezo injectors restrains them from going all the way to the nozzle? Anyway I will be watching and report back.
    The entire job was done at a close friends' auto repair shop. He charged me 250€ for the entire job. The pump I got online brand new on ebay for 465€ including shipping to Greece from Germany. I did some research and it is a post 2012 pump with a better (in theory) design. I could not get a 2 micron filter properly fitted in my engine bay in the return line to protect the low pressure system should this happen again due to partly spacing issues and mostly long delivery time from the US. I am just hoping for the best I guess.
    Sorry for no pictures but I was away from the shop most of the time. It took him 2 days working on my car on and off.
    Excuse any language mistakes, I am a greek.....
    Last edited: Jul 7, 2017
    cakar likes this.

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