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My 2002 TDI Jetta smokes really bad when I accelerate hard for passing, etc. I don't think it did it as much when I first got it but now seems to do it more and don't seem to have the power it had at first too. It has decent power but seems pick up and go is not as strong as before. VW mechanic told me I needed to pay $200.00 to have head removed and carbon cleaned off. Was he telling truth or just wanting more of my money? Costs almost $100.00 an hour to have VW dealer work on it anyways. I would like to have less smoke and more power so is there a way to get this done? Thanks for any info.
 

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That's normal for a diesel. Basically what you did was a thing called "rolling coal". Where you stomp on it and since the engine can't burn all of the diesel going into the engine it comes out as black smoke. It's perfectly normal. The best way to clean the carbon out is to take it on the highway and bring it up to 70 for around 20 to 30 minutes. Cleans it out the best by burning it at a higher temp. That or get carb out I think it's called. That or gum out. Just go to auto value store and tell them you want to clean the carbon out of your car but don't know how. They will help you.
 

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SB
I am having a similar issue with my 2006 TDI 1.9L. HOWEVER, I am having some other problems too, which may mean entirely different things for me and you.

I noticed a while ago, that the engine is now very slow to accelerate until about 1500 RPMs, then it pulls hard (with a puff of black smoke). Not a little puff, a big puff. Enough for me to see it in the rear view mirror in the headlights of the car behind me.

That seems to be new. IIRC, it used to accelerate pretty hard from about 1k RPMs (very little "lag").

A VW specialist mechanic DID tell me the "throttle plate" was blackened with carbon and soot and needed cleaning. I paid for half hour labor to have that done (he was doing other, unrelated work too). Unfortunately, there is another problem with the car that MIGHT or MIGHT NOT be causing or exacerbating the low power/black smoke issue. Until I get that repaired (working on it), can't tell you if cleaning the throttle plate did anything for me.

Your post is quite old (5 months), so please post a FOLLOW UP and explain how it was repaired (or not) to benefit others. Thanks!
 

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The turbos on the TDIs are variable. The vanes may be sticking then
open up when you hit a certain RPM, thus the sudden burst of boost requires
fuel, and you get the black smoke. That black smoke is basically, unburned
diesel that's pushed out on the exhaust stroke. Without a DPF, that's what
you see.

Cleaning a TB plate does very little unless it's caked enough to hinder
air flow which means, you need at least a 8th inch of build-up on the plate.
However, it can cause it to stick as well, then all of the sudden flip open
to where it's supposed to be, thus the burst in speed, and black smoke.
Usually, though, you'll get a MIL for this.

Diesels do not meter air against fuel like a gasoline car does, it's just the
opposite with a diesel. As long as there is fuel, the motor runs unless the
air supply is completely choked off, and even then, it can run with just the
slight amount of air. This is why a diesel engine can "run away."

Anyhow, yours may be a turbo issue, the vanes sticking.
 

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Mine, however, is only from stomping on the pedal from a stand-still. My DPF
is deteriorating (I don't care either), so I get smoke at WOT from a stand still,
or at any time I go WOT to 60 when cruising. If I stomp on it at 65, I see nothing,
unless on an upward climb, even with all this, it's not all the time.

I used a Spulin torque-mount bushing insert, and apparently, the vibrations from
the motor cracked the DPF, and the continual vibrations are shaking it apart.
Love the HP, TQ. and MPG increase though... No DIESEL emissions in PA, so I
am all good...
 

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I'm sure with it having 233,000 miles on it, it's not going to have the power it did at 52,000. Lol. Thanks
My 2013 has over 230,000 miles as well, no performance issues. It got better due to the
cracked and deteriorating DPF. If kept up, a diesel will continue to perform well into the
500,000 mile range. I also disconnected the EGR for a more complete fuel burn, and
doing that I no longer get a puff of black smoke when I stomp on it.
 
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