black smoke at acceleration

I just purchased a Jeta TDI 2003, 36,000mi. The car was not used for 6 months or maybe 1 year. When I first drove the car at sudden acceleration the car would make a thick black smoke. After I drove it for a few km, the smoke started to fade but it never disappeared. Now I have about 500km (~300mi) and whenever I accelerate there is smoke still coming out, not much but is still there. If I drive constant speed, regardless of the speed, there is no smoke.
One more thing, the car passed the Canadian Emission Test without any problems.
Any suggestions will be much appreciated.

A little black smoke under heavy acceleration is normal.

I thought I had the only TDI that didn't put it out until I pulled into an exit lane and jumped on it to avoid being rear ended. As I was looking in the rearview to see the car about to hit me I noticed the little black haze. This is the only time I have noted it...

When I came into possession of a used '05 golf it would also do the smoke screen at hard accelleration. I mean the first time I "stomped it" the trucks behind me vanished in a brown cloud, but the more I drive it hard (only at specific times and places where I know the acceleration will put a good load on the engine without gaining the attention of the local constabulary) the less
smoke trails behind me. At this point it's just a wisp that's barely visible at full throttle. The advice others have offered holds true: don't baby the engine. It really needs to have the carbon blown out.

RT1 said:

The advice others have offered holds true: don't baby the engine. It really needs to have the carbon blown out.

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So... what would be the best way of getting the carbon out then? Open road at 90, punching it at a stoplight, or some concoction of chem removal?

I drive on the freeway 600m per week at 80MPH and that doesn't seem to do it.

Dude, your driving a Diesel. Soot is your new trademark!

Run it up to speed as fast as you can (drage race it: Italian Tune up, etc.) when entering the highway for a couple of weeks. A steady 80 MPH won't do it.

Go for WOT in 2nd and 3rd and then cruise steady once to speed. You want the turbo to spin up and make max boost. So, drag race it on to the highway.

Doing this every other day or so once you hit steady state is good for the engine. It'll run and idle better, too.

Fred

P.S. ChromeBuddha below is correct: only do this when warm. I'd run it up to 4K on the on-ramp...

Warm it up shifting at <2400 rpm. Once warm shift at >3000 rpm.

Thanks...

I got an automatic but I get the drill. Sounds like fun really.

So, no fuel additives will help break this stuff loose? I had the dealer, about a year ago, pull the manafold and clean it out manually. Was expensive.

Put it in second, and run it up to 4K rpm once or twice a week. Highway onramps/merges are great for this.

"So... what would be the best way of getting the carbon out then? Open road at 90, punching it at a stoplight, or some concoction of chem removal?"

I don't punch anything from a dead stop. That's too much mechanical stress on too many things. I have a couple of long hills on my hi-way commute so I'll just punch it at the base to take me from cruising at 60mph to whatever speed I'm going when I get to the top. I have an tiptronic so it usually drops down to fourth at high rpm before it kicks up to fifth. Also, in stop and go traffic, I'll put it in manual shifting mode and rather than using the brakes just run it up and down the gears to slow down or speed up. That runs it up to 4000 rpm a few times in first or second. It's fine to run at steady state for long hauls but from all I've read you need to stress the pistons to seat the rings and the turbo is going to soot up and jam if you don't make it ram some air once in a while. It's got to move!

"tiptronic" ? 5th gear? Automatic?

I would check your intercooler for oil, too much smoke could be signs that your turbo is failing as well, but as others have said a little smoke is fine.

If the car sits for awhile, especially far north, the VNT actuator sticks. The boost is there, but not enough, or not soon enough. Very common problem. This is why it began to improve. It likely unstuck itself partially or totally. Have somebody near you who is familliar with the range of the actuator check it for proper movement.

If it sat a long time a purge and new filter might be in order.

wjdell said:

If it sat a long time a purge and new filter might be in order.

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Bingo!

Order this too!

check for cracks in pressure lines ( around intercooler and then the hose next to the EGR) you might have a leak.

I do not believe so - jasonTDI is real good at noises. try a search

I assume you opened the hood. There is often a problem with some of the plastic hoses towards the front of the car where the intercooler is (don't recall which side goes with which car - my B4 has it under the right front headlight). If you feel around the hoses, you will probably find one that is split. You can also try to find it by listening - use a tube to your ear to isolate locations. Good luck!

chromeBuddha mentioned that some smoke under heavy acceleration is normal. What about under normal acceleration? I get a bit more smoke when she's cold, but I get a little smoke when shifting. Not all the time, but maybe 25% of the time. Is that normal?

The black smoke is just incomplete combustion, thats why the cars are turbo charged so they will get more air and burn the fuel more efficient[FONT=&quot]ly, but when you stomp on it and the turbo spools its forcing more air into the engine and to keep up the engine has to still pump alot more fuel in there and its not going to all get burnt. I love the smoke screen!
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Mgranic diesel engines dont have spark plugs right, so they use high compression for combustion, so if the engine is cold or not at opperating temp, its not going to be hot enough to burn the fuel efficiently hence the smoke. As for the smoke when your shifting my jetta does that sometimes, its because your putting the gas pedal down a little bit as you shift for a smooth shift and it just puts a little more strain on the engine.. very normal.....how did your 5spd swap go btw?