Fixing Injectors - martin
hi all

bit of a technical one this, further to some recent postings regarding power failure, i have managed to locate the source of all problems, at least that is what the VW diagnotics test told me. There were a few readers also experiencing this porblem so i hope you find this helpful.

Apparently loss of power can often be due to a faulty injector (often number 3 in diesels) and a diagnostics check should highlight this as so. Anyway, i have been advised to change the troublesome injector and i would like to do this myself, so can anytone briefly say what kind of a job this is? I have consulted my Haynes manual and it seems straight forward enough, do people agree? Do i need to change all the rings?

p.s what i have said regarding causes of power failure only applies in this example, but i hope it can at least be identified as a common problem in VW TDI's and Audis.
Re: Fixing Injectors - markymarkn
I also would be very interested to know how to do this on my astra.

How much do new injectors cost?

Re: Fixing Injectors - Guy Lacey
New injectors can be from £30 to £80 each methinks. Can be an easy job on an older car but I doubt so easy on a high-pressure common rail diesel.

We used to remove our injectors from our Golfs - wire open the injector pin and clean them in the ultra-sonic bath at college - magic!

I would say, that for a job that should take no more than an hour I would prefer to take it to a dealer just in case something goes wrong - e.g. ooops, stripped/crossed thread in cylinder head or whoops, snapped injector as it's as if it were welded in there and I gave it some welly.

Easy job really but up to you!
Re: Fixing Injectors - martin
get ready... a whoping £128 for a single VW injector from main dealer. So don't bother, go to a scrap yard and get one for £20 which is what i did. Ok, it's not of the shelf but if it lasts a yr that is still worth it. Look around for local VW and Audi scrap yards!

I am still tempted to do the job myself, save the labour and VAT, also it's good to get to learn these jobs as and when they occur. Famous last words!
Re: Fixing Injectors - alvin booth
Martin, Have you tried a diesel specialist such as Lucas or Bosch or one of the many private ones in each area.
They will usually service the injector for you which often means a new nozzle.
Much cheaper than replacement.
Re: Fixing Injectors - David W
OK so they are stone age units but I've just had all four diesel injectors cleaned, checked and re-calibrated for about £25 at the local Lucas diesel centre.

Still smokes like wet coal on the stove though.

Re: Fixing Injectors - Alyn Beattie
Ahhh David

The joys of running Landrovers. I have just come across the remains of an early series 1 on a farm. Owner still has original log book. Do I really need all the hassle? (Don't tell the wife)

We have an injection specialist who will check injectors and refurbish if required. 24 hr turnaround. never taken any out of a common rail engine, but surely cannot be that difficult.
Re: Fixing Injectors - martin
I would love to find a local injection specialist, these people seem to be getting less common. VW told me that they do not have any recon injectors, they were none to helpful in fact (just quoted £178 for injector 3) but i have sorted it out now..

>further to an email i sent you some weeks ago I have managed to locate the >problem in my VW Passat's loss of power down to a Faulty 3rd injector, i >ofund this out thanks to a check made by VW diagnostics. I have brought a >used injectore (as new ones cost £135) and fitted it myself. Apparently all >TDI's are proun to this wear item casueing loss of power, Kangarooing etc and the VW computers will pick up the readings from the on borad sensors.

Hope this helps, if you were wondering what the casue could be. One last thing is that i could not get the new injector back in as far as the orginal (which was a real @!#$ to remove) do you envisage this as being a problem

thanks for all advice
Re: Fixing Injectors - Todd
A sign of duff injectors is a lot of white smoke on startup.
Number three injector has a needle lift sensor, which is why it is the most expensive injector.
You should be able to exchange your old injectors for new ones at a VW parts department. You can also buy refurbished injectors from VW which are a bit cheaper. These are identifiable by the part number ending in X.
If you can find a Bosch service center, they can reshim the injectors.
What I mean by reshim is, they put copper washers on, which take up slack, and restore the original break pressure. The TDI has two break pressures because it's a two stage injector.
The thing that wears on the injectors is not typically the nozzle, but the springs. The break pressure reduces as the spring inside the injector wears out.

> Do i need to change all the rings?
No. You can heat the "rings" (washers) with a blowtorch until red hot, then drop in a bucket of water. This is called annealing.

> but i hope it can at least be identified as a common problem in VW TDI's and
> Audis
It's not a problem. They're a wear item.

I wouldn't use second hand injectors unless from a low mileage car.
Re: white smoke - John S
The main cause of white smoke at start up is failed heater plugs. Provided they are wired in parallel, the engine will start on a limited number of heater plugs (down to one, we believe, on friends Xantia!), but the 'cold' cylinders produce clouds of whitish/grey smoke until things warm up.


Re: white smoke - Todd
I agree, white smoke can be caused by other faults such as glowplugs.
The difference with the glowplug fault is that you will get white smoke on a warm engine aswell if it is the injectors.
Any colour you like. - David W
If you really read into the tech diesel stuff you'll find white, blue and black smoke are all variants of incorrect diesel combustion.

Unfortunately it is something that I'm spending too much time on at present.

Re: Any colour you like. - alvin booth
I have read that white smoke is referred to as "quenching" and is normally a result of cold combustion chambers quenching the initial combustion and emitting the colder combustion gases.
Re: Any colour you like. - David W
And you've read right! Never a real problem if it goes in a few minutes.


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