Club 80-90 Forums

Hi all, i've just replaced injector no3 AFN(the sensor one) on my 1z 1.9 tdi as it failed. It seems to run ok, and drive fine, but it seems to have developed a ticking engine noise.. im a little worried, any ideas what it could be?

Many Thanks....

Is the noise happening on every cylinder firing or just one?

It's likely that the injector you have replaced is noisier than the rest, but something to check is the copper sealing ring at the bottom of the injector (in the injector recess). If you haven't replaced it then you really should have, as the combustion chamber gasses can get past this and make what sounds like a ticking noise. If you allow the engine to run with a leaky seal then it will damage the sealing face on either the Injector, the seat or both.

Not worth risking for the sake of a 20p copper washer

Dave.

Thanks Dave, just checked it out and it is definitely that injector making the ticking sound, and its worse. looks like its not seated(sealed properly). bearing mind the injector is new and only done about 12miles since i fitted it, if i clean the bore and fit new copper seals,can i solve this with out causing damage ?



Any help or info very much appreciated

It's likely that you've not damaged anything so don't worry too much. Just make sure you use a fresh washer, as the whole point of them is that they crush and deform to fill any grooves etc in the mating faces. Once they've crushed down once they won't seal effectively again.

When I did mine, there was loads of crud at the bottom of the bore, so I attached a little pipe (think air line) to the Dyson and pushed that into the bore, then scraped GENTLY with a flat blade screwdriver to get rid of the carbon etc. Make sure you get rid of any carbon build up on the sealing face of the injector too.

After that I took a 10 or 12mm wood dowel and taped some fine grade wet'n'dry to the end, then gave it a gentle lapping for a few seconds like you would do if you were lapping a valve.

I seem to remember that when I did my injectors (installed new nozzles) they initially were a little more noisy than they were before, but I had them checked by a local diesel specialist and he said they were working perfectly (and still are now), it will always sound worse if it's only 1 making the racket. To be honest, with my engine on 289,000 miles, the noisy injectors are probably the quietest things in the engine.

Good luck mate, keep us informed

Dave.

Thanks for all the info dave, picked up a washer from euro parts cleaned the bore and the injector, reassembled and now is running lovely with no ticking at all (PANIC OVER)

Thanks again....

Glad you got sorted, that could have been expensive!

Dave.