Audi A4 B6 2.5TDI V6 sudden loud knocking now not idling or driving with smoke

[Curtym]

Hi All,

Unfortunately I would've liked to have found this site through the love of my A4 and not it's potential demise

So the story goes, I went on the motorway down to the shops, absolutely no issues(other than usual). I then come out, start the car to extremely loud pinging and knocking, with a complete loss of power. I drive 20 seconds up the road, the pinging then becomes like a jackhammer, to which it then cut out. When trying to start again, it very very roughly idles shuddering the entire car for 10 seconds before it cuts lumpy as hell throttle only stalls the engine quicker, with ridiculous amounts of white smoke and a strong smell of diesel from exhausts. No chance of driving it anywhere as it just cuts.

Bit of history, very frequently serviced. However since purchasing the car second hand its always had an issue with being extremely loud, an amount of white smoke when starting, and a bad time idling when cold which unless the revs are kept up it will stall until it is warm when it quietens down and maintains idle on it's own. Being a CVT this is a nightmare in a car park after shopping. Granted I'd rather than it not start at all

I did run out of fuel on the Saturday 1st August, the issue with not starting occured yesterday 3rd, driven fine in between with 100+miles driven between 1st Aug and the 3rd Aug. I live in the country so I drive atleast 10miles every journey and like to drive 200miles most days. I completely service every 5k miles. I do drive hard regularly above 100mph cruise, and maybe could go easier on the car.

Prior to the failure, the car had EML on with relation to Throttle Position Open Sensor, but ran fine. Looked like a terrible cabling job which I have rectified since.

RAC ran a diagonstics on the car, with the following results.

Diagnostic Codes RAC DIAGNOSTIC SYSTEM
System Type: ENGINE SYSTEM TEST/VALUES Name: BDG - TDI - 2.5L - 120 (163)
DTC: 00550,Injection regulation opening valve
DTC: 19559,Swirl flap motor; defekt
DTC: 01282,Changeover valve for induction damper
DTC: 01375,Valves engine mounting, 1
DTC: 00532,Voltage supply
System Type: CENTRAL ELECTRONIC UNIT Name: CENTRAL ELECTRONICS - CENTRAL ELECTRONICS DTC: 01331,Driver door module
System Type: PARK DISTANCE CONTROL Name: PARKING ASSISTANCE - 4-CHANNEL DTC: 00625,Road speed signal
System Type: STEERING WHEEL ELECTRONICS Name: STEERING WHEEL ELECTRONICS - DIAGNOSE DTC: 01331,Driver door module
System Type: AC SYSTEM Name: CLIMATE CONTROL - CLIMATRONIC DTC: 00819,A/C pressure sensor DTC: 00532,Voltage supply
System Type: INSTRUMENT PANEL
Name: INTERIOR MONITORING - DIAGNOSE DTC: 65535,No trouble codes stored in the system

RAC guy gave good advice and a few tests but I shan't say what to not lead anyone's opinion.

Please help I adore this car, and wouldn't like to see the back of it.

I'm kitted out with spanners tools etc. and don't mind spending on special tools etc. (Within reason) for testing.

Is it also worth fixing aswell? Cars at 160k miles will it go much longer? I read 250k and beyond with the 2.5tdi but what is your experience?

I can upload photos, videos and sound recordings if needed.

Hope someone can help!
Curtis

 

[Mike B]

I havent looked on here for a while but sorry to see you have had no response.I have a 2.5tdi which has been in the family for over 10 years and is still a great drive being a high end quattro auto.I am not at all clever with major fixes but with my son we have always serviced and done the simple things ourselves.It may help to get a VAG diagnostic done but I wonder if you know when the belts were last replaced.When we got ours it wasnt running at all well so the belts etc were done and the timing found to be well out so just maybe yours has slipped on the timing belt.As to whether it would be economic to repair this does of course depend on whats wrong but I have long since decided that due to low present values any expensive work even another belt job will be hard to justify.Hope my luck holds and if it does there would hardly any limit to the upper miles on these engines and of course the Quattro autos are sound boxes too

 

[abyrne153]

0550 is start of injection regulation fault generally caused by failure of the vp44 injection pump. It's a common fault on the v6 2.5 TDI engine usually due to failure of the ECU on top of the pump. The pump sits in the v of the engine and with heating and cooling over time the soldered joints in the ECU fail. Pump needs to come off and be repaired by a Bosch specialist. It's a fairly hefty bill for a car of this age so may not be worth it.

 

[joinerman]

OR, you have a tip broke off an injector, ask me how I know.

 

[abyrne153]

Try a couple of simple checks first. See is the lift pump in the tank pumping diesel by slackening the small bleed screw on top of the diesel filter and just hit the starter for a second. You should get a spurt of diesel from the bleed screw (use plenty of rags to catch the fuel). If not the lift pump in the tank could have failed or maybe just a fuse. If all is well with that then you have a fault code on the flap motor. Listen for the flap opening and closing when you turn on and off the ignition. It's located on the intake pipe on the right hand side as you are standing in front of the car looking into the engine bay. If the flap is stuck shut the car won't run properly if at all. Failing that get the pump timing checked as it may be out - but it's unlikely unless it's jumped a tooth on the belt or something. However I would really worry it's the injection pump as they are renowned for it. Oh and block the EGR valve off too if it's not already done as these can cause poor running and hard starting issues and won't throw up a fault code.

 

[Mash Goldie A4]

my 2003 2.5 died the other day. EDC is unreliable and the injector pump as above vp44 needs reconditioning. I found diesel bob in Preston around 715£ to recondition and new EDC supplied but I can't find a specialist who will take off and put the recon *thats the part etc/injector from original car to send to diesel bob. it will be tested and pressures etc. late 2003 models have the imbolisor to contend with beside some form of calibration is required after fitting back the pump. anyone know of a specialist who can do this?

 

[Curtym]

my 2003 2.5 died the other day. EDC is unreliable and the injector pump as above vp44 needs reconditioning. I found diesel bob in Preston around 715£ to recondition and new EDC supplied but I can't find a specialist who will take off and put the recon *thats the part etc/injector from original car to send to diesel bob. it will be tested and pressures etc. late 2003 models have the imbolisor to contend with beside some form of calibration is required after fitting back the pump. anyone know of a specialist who can do this?

Hi, I believe I have just the person check this here they resolider your old one so that immobilizer doesn't throw a fit!https://www.ebay.co.uk/itm/REPAIR-S...716513?hash=item41f73b0ce1:g:gRAAAOSwNRdX9nHP or search VP44 repair on eBay! unfortunately had to scrap the car could've cried but luckily got my hands on a nice A3 !

 

[Pie-eyedpiper]

I used to have a C5 A6 2.5tdi quattro sport. The VP44 fuel pump went on that at about 100k miles. Very expensive to repair but I had it done as I loved the car. My fuel pump went whist actually driving the car though, not on start up, no prior symptoms.
Eventually it was the Tiptronic 'box that did for it. The V6 was a great engine, never used a drop of oil between services and was on a out 160k eventually. I sold it as a non-runner and some Polish boys bought it and probably had it back on the road that same night.