Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Hi All,
I've been fighting against it over the past few months, but have finally accepted that I need to get a set of injectors done.. somebody said this was my real problem ages ago, and I'm coming around to thinking that they were right.
It's just a really expensive repair.. so before I book it in, I'm hoping somebody can confirm the diagnosis. I have no VCDS, so using software readouts for problem solving isn't an option for me at this time - no replies asking me to read MVBs 72-77, please. What I do have to work with are the following observations :
a) Oil level in sump rising. This was measured as approx 330ml over 2months/2000miles.
b) Engine smokes if I "boot" it. Hardly smokes during normal driving, especially if I keep the revs down.
c) Startup tick - every time after being left, but not after a short journey with a short stop
d) Hot start - engines appears to "jam" at a point in the cranking. The lights dim for a second, then it starts off again and the engine will always fire..
e) When idling with the engine cold, a "more than normal" quantity of white smoke is emitted from the exhaust
f) Slightly sluggish performance when cold
I'm pretty sure I can add this lot up to equate to "leaking injectors".. lengthy explanation below.
Leaking injectors (still leaking after the engine has stopped!) will let unwanted fuel into the combustion chambers. If the car is left for a while, long enough for the piston rings to shrink back, this fuel will happily work it's way into the sump - observation A. If it's not left for long enough for this to happen, I believe this causes observation D - where the engine basically experiences "hydrolock", and the engine will either force past this point, or the built-up pressure will force the fuel past the rings and also into the sump. This is the biggest worry for me - hot starting under these conditons can't be doing the engine any good..
The startup tick I ascribe to the condition where only some of the fuel (or fuel/air mixture) is left in the chambers - surface residues etc, and just takes the overall mixture off-spec for the first few cycles - until essentially burnt off or blown through - and causes slightly early detonation. This is a worrying "feature", but doesn't sound nearly as bad as hot starting..
As for the smoke, which i'm assuming is indicative of a bad fuel/air mixture, I beleive that when the engine is run "faster than normal" - for me - they'll be operating at higher pressures etc, and therefore the error on injection quantity will rise proportionally to load. I know that the ECU adjusts itself over time (based from sensor feedback) to trim-up or trim-down the specific injection times for each injector. It is this mechanism that I beleive has left me with a drivable car so far, so long as I keep the revs under 2.5k it's fine... but these timing adjustments are what I believe are captured in MVBs 72-77 (or whatever blocks it is). I bet if I looked, one or more of them would have a massive -ve adjustment.. as excess fuel just blasts by.
Finally the white smoke seen at startup idle, I think this is a normal condition for a cold engine - clears right up when warm. However, I believe that the injectors leak more fuel when at operating temperature, and therefore the "learnt" adjustment in the ECU is not right... i.e. not opening for long enough to let in enough fuel. This might explain the slight drop in performance until the engine has warmed up.
Reading back over past posts, I think that the injectors failing were responsible for excessive soot being re-circed back into the inlet - which blocked the EGR (causing really poor MPG), and finally causing the swirl flaps to stick, causing the other eccentircities that I was having in the first place. Removing the swirl flaps was still the best decision that I've made so far!
So.. I've done my homework, thought about it for long enough, what am I waiting for ? Concerns -
1) Don't know if I need all six injectors done - and they're costly.. amount of fuel accumulating in the sump is not excessive, might indicate that they're not all goosed.. yet. But is it seriously worth replacing less than a whole set ? There's the cost of repeat repairs to consider here..
2) Don't know if the startup tick I can hear is def the injectors - but I assume if it was a chain noise that it would do it *every* start.. perhaps somebody who knows first-hand can confirm
3) Don't know that the hot start problem doesn't lie elsewhere - and this is the one that I'm seriously concerned about.. don't wanna spend money (and commit to own the car for a while longer) and get trapped into spending more money not much later. We all know the shape of this particular trap..
Thankyou for reading if you made it this far, I know my posts are... verbose. Who wants to be the first to weigh-in ?
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Have you got prices as yet? Am assuming you'll not be DIY as you've said 'before I book it in'.
I'd firstly see what other forum members (esp Gup) advise in purchasing them yourself and then ask local companies to try and match that price.
It may keep the costs lower...but as you know they are pretty costly.
The alternative would be to try to buy some from a scrapped 07+ car, which had the newer style injectors.
As to who you use, my local VAG specialist (Wagenworkz in Highbridge) charges £35 per hour, so worthwhile comparing labour rates.
These on Ebay seem to be the cheapest for a set of 6
6x new Audi A4 A6 A8 Q7 VW Touareg 3.0 TDI Bosch injector 059130277BD phaeton | eBay
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Thanks for the info Mark - appreciate it.
I've seen Gups' posts ref injectors (and read a few others!), and I have shopped around a bit for the job. The best quote I had was £1500 inc vat and fitting. Normally I'd do jobs like this myself - very rare for me to pay somebody else to work on my stuff - but obviously the ECU needs to be told about the new injectors (job I can't do), if I arrange service/ex injectors myself I need to pay deposits for the exchange (and later re-claim), and ideally it would be done in a clean environment. The clincher was that if I ever needed/wanted to make a warrenty claim on the injectors, it would help to have a garage invoice for the fitting. The actual breakdown given to me for the job (best quote) was £110 +vat for the fitting, including new fuel filter and ecu coding etc. At that price, I don't see as it's worth risking the warrenty, having to buy a fuel filter, or an injector puller (I'd buy one if planning the job - to make sure I don't have to leave it half done)..
If anybody is interested in where the best quote came from PM me... Bristol based.
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Quote:
Originally Posted by
edwardsj
The best quote I had was £1500 inc vat and fitting.
That is very reasonable!
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Hi, did you ever find the cause? I have exactly same problem
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Can anyone confirm if the AH injectors (dropped in 2009) are also leaking or will these be sufficient.
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
The vcds readouts are just an indication and sometimes not accuate. Get the injectors on a test bench to be sure
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Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Thanks, I would but I cannot afford to pay someone to test something where all documented symptoms show leaking is indeed the case. I have the rattle on startup (not to be mistaken for the chain tension thing) I have the same described starting issues at different stages, and I have the white smoke ploom from the exhaust that only happens if I am sitting still for any short length of time, and while increasing the rev to 1k does stop the smoke I realize this is not a solution.
I have a quote from a breakers yard for the more updated BD injectors so I think Im going to get those, and have my local garage give them a good clean and fit them.
Re: Sorry - Yet Another Injector Thread - 3.0 V6 TDI
Quote:
Originally Posted by
MarkTM
Have you got prices as yet? Am assuming you'll not be DIY as you've said 'before I book it in'.
I'd firstly see what other forum members (esp Gup) advise in purchasing them yourself and then ask local companies to try and match that price.
It may keep the costs lower...but as you know they are pretty costly.
The alternative would be to try to buy some from a scrapped 07+ car, which had the newer style injectors.
As to who you use, my local VAG specialist (Wagenworkz in Highbridge) charges £35 per hour, so worthwhile comparing labour rates.
These on Ebay seem to be the cheapest for a set of 6
6x new Audi A4 A6 A8 Q7 VW Touareg 3.0 TDI Bosch injector 059130277BD phaeton | eBay
Interesting that you say 07+ cars had the newer style injectors, whats different about the design?
