A6 diesel starting problem

[Bob Heritage]

I have an Audi A6 Avant 2.5 diesel 1999. The car will not start. Have checked for air in the fuel and that is O.K. I have bled the injector pipes and the pressure is strong. Occasionally I have managed to get the engine to run but it dies out after a short time and on checking the pressure at the injector pipes there is only a weak feed at this time. Any ideas?:confused:

[adamss24]

Diesel pump ?!!!

[Simon Evers]

Hi everyone, I've just joined the forum as I too have a problem with my A6 2.5 TDI starting. In brief I was returning home from a motorway journey and had pootled all the way home at about 70/75 (just enjoying the drive). Having stopped briefly and switched off, I tried to start the car again and it just kept turning over like there was no compression. After a few attempts it did eventually fire but with no guts at all and some smoke. Eventually I managed to hold enugh revs to slip it into 'D' and creep the 200 yds home. After letting it cool fo ran hour, it started but was very lumpy. I tried it again this morning with a view to taking it to a local independant VW/Audi spanners but again it died. having spoken to him, he suggested Oil level, but this is fine. So now I am stumped? Any assistance/advice wuld be most appreciated. Cheers.

[Bob Heritage]

Hi Simon, Your problem has all the symptoms that I had. I tried to get advice from Audi main agent but all I got from them was 'book it in sir and we will analise it'. Eventually I was recommended to a diesel specialist who put a lap-top on the injection pump to get a readout. Unfortunately the result was terminal. I got a quote from Audi main dealer for approx £2500 inc V.A.T. and one from the diesel specialist who sent the pump away for reconditioning for £1500. all O.K. now but still getting over the cost. Incidently Audi were going to remove the entire front of the car including bumper, but the diesel specialist managed to leave the front intact including the radiator and managed to refit the pump with it in situ (the pump has to timed via the belt) You can do this on a V6 but not on a straight 4 as the block is slightly longer. Although you will not be able to replace the timing belts this way if you decide to do this at the same time. I checked all alternatives before hand but in the end this was the result. The best advise I can give you is to get the readout first, it will save you a lot of time. Sorry to be the bearer of bad news.
Regards-Bob

[Simon Evers]

Many thanks for the response and advice Bob. I have had a mechanic here this evening with his diagnostic computer. We got the car started and ticking over. Whilst it was very lumpy to begin with, it did smooth out but occasionally did die out. His machine came up with an engine code fault:- 00550 - Injection Commencement Regulation. Does this ring a bell with you Bob or anyone else for that matter.

[snapdragon]

It may be the start of injection sensor which is built into the injector with the wire coming out. Check the wire etc... I think this injector is £250!!

[Bob Heritage]

Hi Simon. All sounds so familiar, I did not get the code when mine was diagnosed, try giving Audi main dealer the code or a Bosch agent you might get a result, although like you it was pointed at the injector pump. The A.A. did get mine running at first by bleeding out the fuel pipes but this was short lived and the problem returned which left me getting a relay back home. Good luck.
Regards-Bob

[shabazmo]

A Bosh fuel pump specialist will be able to read the fault code from the pump which is different from the fault code from the car. If it is the diesel pump then the front end has to be pulled forward which means bumper off. Best to get timing belt changed at the same time as much of the work is done by removing the fuel pump. When the pump is off send it to PB Asher in southampton. They will dianose and repair for about £500+vat. Ther are trully a professional Bosch specialist. They will collect the pump and return it if you are far from them.
If not the pump then it could be your timing belt tensioner bolt which failled on my car causing the belt to jump and the same symtoms as yours. I know this is a common problem as the "Thread Doctor" who repaired and inserted a new helicoil said he had done about 16 Audis this year.
Keep in touch
regards
Shabaz

[Simon Evers]

Some interesting replies guys, and thank you very much. I'm kinda ruling out timing belt jumping, unless I am completely missing something; as it was fine when I pulled up at the cash machine, then wasn't when I came to drive away. When the guy came over with his diagnostic computer, he actually got it going and ticking over, but he did have to push the squirt pedal into the carpet to get some fuel through. It would tick over for a while and after being initially quite lumpy did start to even out. However, it did die again. He was quite sure it was fuel related.

I hate having a broken car and being unable to fix it. :aargh4:

[Simon Evers]

Hi everyone, back agin o this subject. guess what? I found out wha the problem is.....Diesel Injection Pump drive belt has stripped its teeth. Get this though, in replacing this belt, the Cam Belt needs to be done (whihc I would have done anyway), unfortunately the job can only be done by an Audi Main Dealer as there are special tools invloved. My local Audi dealer quoted me £1100 just for a cam belt change. However, Stafford Audi are offering a V6 TDI cam belt change for £395 as advertised on ebay. After speaking to the very helpful service receptionist, they have quoted me for the cam belt change plus water pump (apparently this should be done when cam belt is changed) plus tensioners, plus diesel pump drive belt, plus all grooved belts for £525.00.....RESULT. Obviously this is subject to there being nothing major wrong in addition and which would have caused the fault in the first place. All that reains for me to do now is to find an inexpensive way of getting my car from Worcester to Stafford.

[ncrichton]

Can anyone help me? I have an A6 1.9 tdi avant 53 reg which intermittently will not start. usually it fires straight away but sometimes the engine turns over but will not start. The problem has left me stranded twice. On the last occasion the AA managed to start the car by pumping some diesel into the fuel filter manually. At present the car seems to be running perfectly again and the garage say they can find no faults with it as there are no warning lights on the dashboard and no problems appearing when it is connected to a computer. Do I have to wait until it breaks down again and get it towed to the garage (which is what they suggest) This leaves me feeling very uneasy and unwilling to go on any longer journeys.
Help!
Thank you
Neil

[micheal balbrig]

Can anyone help me? I have an A6 1.9 tdi avant 53 reg which intermittently will not start. usually it fires straight away but sometimes the engine turns over but will not start. The problem has left me stranded twice. On the last occasion the AA managed to start the car by pumping some diesel into the fuel filter manually. At present the car seems to be running perfectly again and the garage say they can find no faults with it as there are no warning lights on the dashboard and no problems appearing when it is connected to a computer. Do I have to wait until it breaks down again and get it towed to the garage (which is what they suggest) This leaves me feeling very uneasy and unwilling to go on any longer journeys.
Help!
Thank you
Neil

Sounds like diesel is running back to tank occassionally possibly
due to loose hose/clip or filter that is not sealing properly.
Was car facing up hill on occasions when it refused to start?
Best to try all hose connections for tightness from fuel pump back to tank and check filter for tightness also, There is probably a non return valve near filter which may need checking

[ncrichton]

Thanks for your advice Unfortunately the garage have tried these and there is no sign of a problem with connections etc. The problem does not relate to whether the car is on a slope. The most recent occasion was when the car was parked on a flat surface. Has anyone else had a similar problem and found the solution?
Thank you
Neil