53 Plate Audi A3 TDI 2.0 BKD Slight Shudder

[anathemaMark]

Good Morning, and hello, my first post here.

My audi went in for a check-up as I was worried my turbo was on the way out (it makes a whine when spooling up and very occassionally some black smoke on accelleration. It also has a slight shudder at idle when warm. The garage cleared the turbo as fine, but when hooking up to VCDS, the injector status reads "004 = Low Injector Quantity or Injector Faulty" when it is revved to 3000 in neutral for all 4 injectors. I was told this could mean nothing (especially as it happens across all 4 at the same time), as it may not be getting enough fuel as not under load. Or it could mean i need 4 new injectors :-(. This suprises me a little as I have a slight shudder when at idle, which I think may be timing, as it sometimes has a slight lumpy start with a little black smoke but never mis-fires under normal driving and has no fault codes, other than 2 glow plugs.

Could anyone shed some light on what those values mean? and possible things to check.

I should also mention that it drives fine and my MPG seems pretty good

Thanks in advance

 

[max69vk]

That code doesn't mean nothing, it means theres a problem. Start with the easy things first, have you removed the fuel filter & checked its not blocked as that can cause fuel starvation at higher revs, it can also contribute to rough idling but as you've already said that may be down to the timing. If you've got access to VCDS to check the timing go to Engine>Measuring Blocks>Group 004>Box 4 , this should read around 0.0-0.5kw.

Also I forgot to mention, sometimes a fault code coming up on the glow plugs can relate to the injector units too, check the other bits I've mentioned first & then try throwing a Redex gold through the tank (not the red Redex - its cack) & see if that clears things out.

 

[anathemaMark]

Thanks a lot for that, I dont have access to VCDS but my garage do, i will mention that, it is going in to have the timing checked and a new injector loom fitted too which apparently can also cause this problem

 

[max69vk]

The injector looms shows up as a fault code as an intermittent connection & causes very heavy spluttering at around the 3000-4000rpm mark (when the car hits a particular resonant frequency the connection can break) so I doubt it needs replacing. Just in case, it's also worth checking with Audi UK as they may have a recall on the loom which means they'll do it for free

 

[anathemaMark]

Alas i already called them and they said my car is too early a model their "campaign" doesnt cover me. I will get the fuel filter checked as well when it goes in. Are their other symptoms i would have / should look for if it is 4 faulty injectors?

 

[max69vk]

No power, difficulty starting, lumpy idle, smoking.... The list goes on! The problem with diagnosis is that all of the symptoms could be attributed to something else as well, which is why its best to check the small things first. Also its not an injector fault that your looking for per se as this would show up on a fault scan, if its blocked or or not injecting properly it doesn't always show on VCDS (although you can check injector flow rates).

 

[anathemaMark]

Ok thats great, Thank you very much. I will try cleaning the fuel filter and shoving some radex through (havent used radex since I had a Capri ). Once the timing is sorted I will re-evaluate

 

[max69vk]

If the fuel filter is cacked up you'll need to replace it, they cost about £15 for an OEM from the dealer.

 

[anathemaMark]

thats great, i will order one if it looks dirty. Could i just ask, worst case scenario and new injectors are required, what is the associated cost of this, i gather its high £2000~ is this too much, or is it time to consider a refurbished engine?

 

[max69vk]

I very much doubt the injectors are faulty, just dirty. Try the Redex Gold, if the injectors were shot you'd really know about it & yes, they're damn expensive.

 

[anathemaMark]

Just an update, I have had the injector loom replaced and the fuel filter (collapsed and covered in crap) and now it runs beautifully with a bit more power and also no glow plug faults.

Thanks a lot for the advice

 

[max69vk]

:icon_thumright:

 

[vw754]

mine wont start.........does injector fault or wiring loom show up in vcds? http://www.audi-sport.net/vb/a3-s3-...159349-urgent-help-needed-car-wont-start.html