Carbon build up and black smoke

[basset]

Car is 98 beetle, about two months ago I notice the turbo stopped working so I dug in and found serious carbon build up, cleaned it all out and replace intake manifold, had the head off and hot tanked everything I could, put her back together and she ran better than new for the last month and a half, now I am getting some black smoke, so I pull of the intake and notice what looks like carbon starting to build up again wtf ? HELP !
 I am new to diesels but have got the bug for sure.

[Smokey Eddy]

I dunno TDI's ... my parents 2000 TDI golf has this issue....

The only thing i can think of is maybe a timing problem? carbon in the INTAKE.... thats a backwards place for it eh...

soooooo....

Maybe it's from oil coming off the breather, into the cold side of the turbo, building up in the intake and then cooking?

I'd post in the TDI section to be honest if it is a TDI....


(perhaps the intake valves aren't seating? I have noooo clue.

[theman53]

The TDIs with the EGR thing are known for this. Carbon buildup will eventually plug the intake. A buddy of mine bought a 5 year old car with high miles for next to nothing because it wouldn't run over 1,200 RPM. He told me he took the intake off and parts of it were carboned up to about the size of a pencil. No air was getting to it. All he did was clean it as you did and it ran fine. The couple that had it were old and probably never had the pedal to the floor or even enough to push the carbon through the intake at all.
I would think unless the buildup is excessive then I would just run it. Watch it and clean it if nessesary and maybe run it hard once a trip to help it clean itself. Maybe see if this is a model with the EGR thing and see if it is funtioning correctly.

[basset]

I put a brand new egr on it when I did everything else.

[Smokey Eddy]

The TDIs with the EGR thing are known for this. Carbon buildup will eventually plug the intake. A buddy of mine bought a 5 year old car with high miles for next to nothing because it wouldn't run over 1,200 RPM. He told me he took the intake off and parts of it were carboned up to about the size of a pencil. No air was getting to it. All he did was clean it as you did and it ran fine. The couple that had it were old and probably never had the pedal to the floor or even enough to push the carbon through the intake at all.
I would think unless the buildup is excessive then I would just run it. Watch it and clean it if nessesary and maybe run it hard once a trip to help it clean itself. Maybe see if this is a model with the EGR thing and see if it is funtioning correctly.

Exactly. Since i've been allowed to drive my parents Golf it hasn't had the build up since. Likely because i more frequently take it to 4,500. :twisted: