So after replacing my injectors, no difference.

Had black soot on the tail pipe but internet says id get codes if the dpf was cracked, especially from the pressure sensor.

Seems to smooth out but not go away with warmer intake temps.

So im thinking theres a miss match between my MAF and upstream lambda sensor.

Would that make sense?

Should I look into replacing both?

Again 0 codes or warnings.

4 minutes ago, SquidgyB7421 said:

Again 0 codes or warnings.

Are you using FORScan and a 'vLinker FS' cable ?

Lambda isn't used for fuelling on diesels. 

It's only there for NOx reduction (EGR & throttle body control).

1 hour ago, unofix said:

Are you using FORScan and a 'vLinker FS' cable ?

Obdlink ex cable.. but yes

43 minutes ago, TomsFocus said:

Lambda isn't used for fuelling on diesels. 

It's only there for NOx reduction (EGR & throttle body control).

Okay. Thank you. Cant be that then coz my emmisions are fine

Im still at a loss tho...

Warmer intake air means less dense, so turbo doesnt work as hard, and mixture is easier to ignite...

So i can guess at 3 things.

1 Turbo is failing

2 restricted intake

3 somethings off with the MAF

I can say, whilst doing some intake cleaning with jlm egr spray cleaner and that diesel revive stuff... Things did change for a little bit, but then came back.

 

 

Or glow plugs... But no 1 thing is big enough to throw a code?

1 hour ago, SquidgyB7421 said:

Okay. Thank you. Cant be that then coz my emmisions are fine

NOx is not tested at MOT so you wouldn't know either way.

Glowplugs seems like a good shout though.  They are used during the warm up phase to reduce particulates and smooth out the idle.

1 hour ago, TomsFocus said:

NOx is not tested at MOT so you wouldn't know either way.

Glowplugs seems like a good shout though.  They are used during the warm up phase to reduce particulates and smooth out the idle.

Well halfords red lined it and said my emmisions failed. Another place held it at 4k rpm and said it was clean as could be, so would indicate dpf is fine. My pressure climbs and falls as it should.

I serviced it with oil, and the air, oil and fuel filter after that and that didnt have an effect.

I flushed the intercooler and used those sprays i mentioned earlier for the intake side. Cleaning the throttle body helped but only temporarily, and using the revive stuff calmed it down for a while but came back, so i may have a slightly choked intake.

I changed all the mounts and that made no difference.

I changed the injectors and that made no difference.

The only thing that seems to calm it down is a warm day where the air going in is over 15c.

Again, never had a code, missfires or knocking, no smoke, no problems starting.

It idles better if i have warmed it, stopped for a while and restarted, as in vibration wise.

So.. im gonna lean towards glow plugs being the last thing left.

Clutch operates fine and gear stick isnt stiff or clunky and no vibrations other than the general footwell ones passing through a bit.

Just a shame that three mechanics who ive asked to try and determine whats causing it have fell flat. One said nothing visually but didnt test anything else, one said hydro mount but didnt test anything else, and one said live data didnt show anything so didnt bother testing anything else.

Gonna go to a Bosch diesel place near me and ask them specifically to do all the tests i cant. Intake smoke test, vacuum check, scope the dpf for condition.