Audi 170 tdi injector / tandem pump advice

[Santa Cruz]

Hi all,

Im new to posting on this forum but have been reading a lot of the very useful posts.

Im after a bit of advice here, i have a 56 a4 170 tdi with about 80k on the clock. About 3 months ago it started to get the dredded glow plug light issue. When engine is reset disappears and comes back out of limp mode. Under 3k revs the pickup is slow and sometimes a little lumpy. This is happening every ~100 miles, i do mainly motorway driving.

Anyway went to a VAG specialist and we decided to first of all do a dpf regen. This seemed to help for ~ 500 miles but then the problem returned. Next course of action was we believed it was related to vains in the turbo not actuating, so replaced whole turbo, and then mass air flow sensor, and air filter to be sure. Problem still persists to my annoyance.

Then discovered the injector issues on linw and managed to get audi to agree to replace all 4 FOC. Took it to a dealership and they could not find any fault codes nor prove that the injectors were faulty but agreed to change them anyway, however, they also told me i have oil contamination in the fuel caused by the tandem pump failing. I would therefore need new parts, fuel tank clean and new fuel filter at a cost of £850! They said there is no point in changing injectors if this issue is present as it will just contaminate them and is contributing to the problems i am having. I haven't had them changed yet until i consider my options, also audi cannot guarantee me that if they change the pump and injectors it will solve the issues..

Question is do i get the tandem pump changed or risk just getting the injectors done to see if this fixes the issue. I will be asked to sign a disclaimer if they change them without tandem pump but they will still do the work.

Sorry for the long post but this is really doing my head in now and would really appreciate your advice, there seems to be a lot of info on here about this kind of problem, never thought an audi would be as unreliable as this.....

Cheers

[SebRogers]

Seems to me there's no point in replacing injectors if the fuel's contaminated. Can the dealership demonstrate the contamination to you or at least explain how they've diagnosed it?

If the tandem pump's failed it'll need doing anyway. I wouldn't have thought the injectors would be the cause of your problems (should be possible to find out if they're working properly via VCDS anyway), though it's probably worth having them replaced with the updated parts seeing as it's FOC.

Seems to me you need to sort the contamination issue and you might as well have the injectors done. Whether that solves your problem or not... dunno. But you won't be able to get anywhere until the car's running on uncontaminated fuel

[Pork]

Dunno if it's just me but it seems a few people have had a similar experience when taking their car in for the injectors to be changed out of "good will"

Don't suppose for a second Audi would be as unscrupulous as to make the money they are being forced to pay out back by other means???

And I am about one more post away from deleting this forum from my favourites as it's putting me right off my car!

[gaz1965]

[QUOTEAnd I am about one more post away from deleting this forum from my favourites as it's putting me right off my car![/QUOTE]

But when they are running as they should its an awsome motor.

[Crasher]

Tandem pump failure is common. I empty the system with a hand pump recovery unit, clean the fuel pump, blow the lines through and fit a new filter and of course tandem pump, an expensive job. After a few tanks of diesel the system should be clean enough to fit the new injectors.

[Santa Cruz]

Thanks for all your advice.

Unfortunately i dont think it helps me answer my own question... The thing i am struggling with is if the fuel was contaminated with oil as a result of the tandem pump, would i not have a continual issue rather than the intermittant problem? I drove to the airport and back last week and did ~250 miles to only have the glow plug come on once, i reset the engine and then was back on my way, very strange. The stuttering is also very sporadic.

Im thinking i might just get the garage to do the injectors now see if it makes any difference and then re consider my options. I certainly wont get Audi to to the tandem pump at that price, they wont even gurantee this will fix my problem, i will probably look for a specialist.

[shan2788]

Hi all, new to all this so bare with me!! Ive got a 2006 2.0tdi a6. I came home from long journey and half way through started noticing a little power loss didnt think much off it then next day car wont start when i mean wont start i mean it runs for only a couple of secs then dies like it out of fuel so after doing so research and starting from basics ie fuel contamination i removed lift pump to find like a coke coloured fuel so i thought failed tandem pump as it seemed the coke coloured was oil in the fuel so i replaced tandem pump and fuel filter and clened fuel lines and put clean diesel in with no luck still the same. There are no stored malfunction could it be just a case of keeps trying to start it and get clean fuel through or am i missing something

[Crasher]

It may be that was not your problem but you need to get clean fuel through first.

[shan2788]

Any idea crasher like i said there ain no fault codes im using vs pc to scan im just lost i dont know wat to do next lol thanks for the replay crasher

[Crasher]

After introducing an air lock like that it can take a lot of running before the fuel pulls through so we gently bring them up on brake cleaner but very very carefully and with one hand on the ignition key to shut it down should it suddenly run away which is a very real possibility, is scary and can easily destroy the engine.