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Clacking sound after injector replacement on 1.6tdi

Posted: Tue Feb 17, 2026 10:14 pm
by dfh_21
Hi all,

bought a vw caddy 2011 last year and had injector go on it straight away. I took it in somewhere who replaced it with a Lucas injector 432441022. Didn't know anything about the history on these injectors at the time, but understand replacing with this injector type is not advisable?? I dont know why the garage advised me this one which cost £333 (after trading the other in i think) when a Siemens VDO is a similar price.

The van drives now but has a knock/tapping/clacking sound when pulling away under load. The garage didnt know why this was happening and tried to advise me on getting a new engine lol, maybe to try and cover themselves. Dont trust them at all, and feel if the right part had gone in then it probably would be ok. Not sure what leg i stand on trying to argue that with them as i cant be sure.

Could it be that there not coded properly? or are reconditioned parts (which i think the Lucas might be) just needs to come out?

Thank you!

Re: Clacking sound after injector replacement on 1.6tdi

Posted: Thu Mar 05, 2026 6:47 am
by STP
I'd think the Lucas one can't be coded to the ECU as the number won't be recognised, likely you need the Siemens VDO unit. Then it can be coded and the number off the top of the injector ring will be accepted.

Uncoded injectors can knock and generally run a bit rough if not coded. Can't just plonk one in and have it working without coding. The code tells the ECU something about the stroke and volume basic settings for the injector and they are all slightly different.

For example I know you can fit Ford tdci injectors in a pinch but they can't be coded. Been looking for a tool to convert the ford code to a VW one but never came across anything. They work but run a bit rough. Those are significantly cheaper than the VW ones (Siemens) so it would be good to be able to use them but not turned up the info anywhere to do so properly.

Re: Clacking sound after injector replacement on 1.6tdi

Posted: Thu Mar 05, 2026 10:50 am
by dfh_21
Hi, thanks for your message.

I have since looked at the injector coding with another mechanic and all of the codes were wrong, which was very odd. Not sure why the previous garage had done that.

However, when we put the right codes in, it made no difference really. Would have to check again if it fully accepted the Lucas code, but he didnt mention any problems when inputting it. Does the ECU need some time to adapt to new codes, or should it affect it straight away if its going to?

Cheers

Re: Clacking sound after injector replacement on 1.6tdi

Posted: Mon Mar 09, 2026 9:00 pm
by STP
It should work straight away but you also likely need to reset the learned injector values (fuel correction)

Have a look at this page on Ross Tech, if you have VCDS, this could be how to reset the learned values and get rid of rough running:

DIESEL 1.6 TDI CR Injector quantity adaptation, IDE06141 | Ross-Tech Forums https://share.google/dpCGIwra61U29uTNo

Never tried this one myself but it must be possible with VCDS.

Re: Clacking sound after injector replacement on 1.6tdi

Posted: Mon Mar 09, 2026 9:43 pm
by dfh_21
Thanks for sharing that - look promising given peoples comments on that video. Will give it a try!

Re: Clacking sound after injector replacement on 1.6tdi

Posted: Fri Mar 13, 2026 2:15 pm
by dfh_21
Thanks very much for pointing me in the direction of this. Just had my mechanic run it (luckily i had the later ECU software as it cant be done on early 88XX versions from the sounds of it) and it now drives smoothly! all the clacking sounds under load have gone, which is amazing - not quite sure how its done it

Cheers

Re: Clacking sound after injector replacement on 1.6tdi

Posted: Fri Mar 13, 2026 10:26 pm
by STP
Fantastic, glad to hear it. Nice one mate.