Black smoke

JBDeVega · **Posted:** Fri Jul 17, 2020 6:27 pm

For a while now I have been getting black smoke out of the CRD whenever I accelerate from a dead stop. if I accelerate slow enough it doesn't do it but from what I've been reading it most other owners don't experience this. What's more alarming is that when I give it full throttle it also puffs out black smoke the entire time I'm at full throttle, speed and RPMs seem to make no difference on this one.
All Turbo hoses are aftermarket silicone hoses replaced less than 10k miles ago, I had the entire top end taken apart and cleaned no even 2k miles ago. Just replaced the MAP sensor as well as the boost vacuum solenoid and vacuum modulator and filter. at this point, I'm suspecting replacing the turbo or the injectors. anyone got any ideas what may be the issue?

flash7210 · **Posted:** Fri Jul 17, 2020 7:17 pm

Black smoke means not enough air.
Have you changed the air filter?
Have the rocker arms ever been replaced?
Any trouble codes?

Does having the AC on make any difference?
I know it does on mine.

WWDiesel · **Posted:** Fri Jul 17, 2020 9:43 pm

Based on your symptoms and all the things you have already checked,
Sounds like you could have a low boost situation.
Do you have a boost gauge, if not, adding one can tell you volumes as to whether the problem is lack of air/boost related.
One of the first things to check is the stroke of the turbo vane actuator to make sure the turbo vanes are not sticking or hanging up and not allowing full boost when called upon.
Another thing that can cause low boost issues is a cracked or partly collapsed vacuum impulse line between the turbo vane actuator and the turbo modulator valve.
Several including myself have found this little plastic tubing damaged or partly collapsed and have replaced the plastic tubing with high quality silicone hose.
Of course a leaking CAC (intercooler) or EGR valve leaking can cause loss of boost if you still have an EGR system in place.
The FCV can also fail and stick partly closed limiting boost to the engine.
Most CRD owners remove all the EGR, EGR cooler, and FCV crap off this engine since they are nothing but engine killers.
A stopped up CAT can also limit turbo performance and cause low boost issues due to high backpressure on the exhaust system.
The CAT can be removed with NO adverse affects, only benefits, many owners have done this. :wink:

JBDeVega · **Posted:** Fri Jul 17, 2020 9:55 pm

Air Filter has 6k miles on it and its been doing this even with a brand new filter.
Rockers were just replaced 2k miles ago when the top end was taken apart and cleaned.
no codes and haven't tried with the AC as I never use it.
I was thinking a low boost issue but it's hard to tell as I have no number to compare to. I do have a boost gauge but it does some odd things like periodically fluctuate 1-3 PSI when driving (when RPMS and speed remain same). On full throttle I can see it go up to about 18-19 psi where it tops out, it usually stays around 7-12 psi in normal diving and accelerating.

Never heard of checking the stroke of the turbo vane actuator. What does that entail?
when I replaced the actuator, I didn't see any physical damage or holes in the vacuum tube lines. But the fluctuation in the boost makes me suspect something is wrong with the vanes either acuating or getting stuck. Can you provide a picture of what tubes may be known for collapsing/damaged?

WWDiesel · **Posted:** Fri Jul 17, 2020 11:23 pm

It's the small plastic tube that runs from the turbo modulator valve over to the turbo actuator.
Mine was partly collapsed due to the heat. Some others have also found theirs in this conctions and a few have found them to be cracked and leaking.
I replaced ALL the factory plastic tubing with high quality silicone hose.

As to the turbo vane actuator stroke, search LOST, there are several writeups by owners who have done this.

JBDeVega · **Posted:** Sat Jul 18, 2020 8:20 pm

Replaced the plastic hose with a rubber one as that was all I could find in the auto store. may buy some silicone hoses online if you think that will improve it. also removed exhaust side of Turbo and sprayed oven cleaner in there to clean it out... the end result is that he turbo does show improvement in high end boost but still lags in the low end and black smoke upon accleration from a stop and at full throttle.

flash7210 · **Posted:** Sat Jul 18, 2020 8:34 pm

Maybe you just need to drive it hard to get it loosened up.

Last weekend I fired up my CRD for the first time in almost 3 months.
Was hardly getting any boost and lots of black smoke.
Kept trying to accelerate hard and finally after about 15 minutes of driving it started acting normal with full boost on demand.
Still a little black smoke when accelerating from a stop but I’m running a Yeti HOT tune.

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