injector cleaners - to use or not to use?

[Zebster]

Originally Posted by hewking

just bought xc60 d5 2012 150k milesand would like to take care of it hence questions regarding injector cleaners- are they helping or harming?
people claim that they clean various deposits also from the rubber but others claim that the cleaning process can clogg injectors as well.
Could you pls share your opinion?
my mechanic mentioned that wurtz diesel verbesserer is quite good but i forgot to usk whether for me or him

Is there a reason for believing that your injectors are blocked and actually need cleaning? I suspect that most cleaners (particularly the ones added to the tank) will neither help nor harm.

Standard fuel (normally containing a variety of cleaning additives) passes through the injectors in a series of pulses at huge pressure (almost exactly a thousand times the pressure in a tyre) so I'd expect that alone to keep them pretty clean. All injectors on my previous car (a Honda Accord) were surprisingly clean at 150k miles when I removed them to access the cam cover. In fact the official workshop manual specifically warned against any sort of cleaning.

Fouling of the intake side of diesel engines due to EGR is a far bigger concern in my experience. My Volvo has so far needed a new EGR valve, a new EGR cooler (twice!) and a new intake manifold assembly due to soot and crud building up. My Honda had similar issues.