black smoke on my A4 TDi '99

[00drewski]

i recently picked a A4 '99 TDi and its runs like a dream, i had it serviced and now it smokes black on every take off and gives more puffs as i put my foot down in a higher gear on low revs. it did this a bit on high revs before the full service but im concerned the guys that changed the fluids, filters etc..... messed something up or has a new problem just shown itself as a result of cleaning everything. why's it smoking and what can be done. are my injectors to blame??????( i used an additive to the fuel to clear the injectors)
appreciate your comments

[onzarob]

All diesels smoke on hard acceleration, but they do smoke more if they have been drven easlly for a long time, my TDI was smoking when i first bought it, but I put in an injector cleaner and then drove it using more revs, 8 months later and 10k and its only smokes when i really boot it now.

[00drewski]

All diesels smoke on hard acceleration, but they do smoke more if they have been drven easlly for a long time, my TDI was smoking when i first bought it, but I put in an injector cleaner and then drove it using more revs, 8 months later and 10k and its only smokes when i really boot it now.

hmmm. im not really sure im ready to let it smoke like it is for another 10K. one its embarrasing, and two im concerned there's a real problem. obviosly a healthier engine or full system doesnt smoke this much. so there has to be a cuase for the effect.

[onzarob]

if you want you can clean the inlet manifold, as it get clogged up a little from the EGR Valve (exhaust gas recirculation). toy need to remove the EGR valve and inlet manifold and clean it, it can't be done on the car. this can help with smoky motors. just more involved.

Also i was speaking to my mechanic and he says that when he does the MOT that he get allot of soot from car that do slow miles. the exhaust fills with soot and only gets thrown out when the car is booted/ revved hard for the emission test. therefore giving it a thrash in 3rd once in a while will clean the exhaust.

How long have you had the car?

Do a search and there are plenty of thread on this.

[cbrpaul]

What they also do for an MOT on diesels to get it through the emissions is rev the crap out of it !!! its also known to be done, to get a car to go better ,and the customer says woow what you done she going so much better now !!!

There should be a warning given to customers that there is a slight chance that this can damage your engine when getting a diesel MOT,ed !!!

Keep on eye on your oil level , if its going down alot , then you may have a turbo about to go !!!

What happens is the turbo is fed with engine oil when the seals go in the turbo , the oil goes into the turbo and in the exhaust !!!!

This usually sucks the oil out of the engine and can cause alot of damage ,

But note that is a worse case scenario !!!

[00drewski]

thanks. helps a lot. i have to unfortunetly rely on my mechanic to do all the checks. i bought the car around six months ago and did a full service and check to all parts and systems. the smoke is 50 times worse after the service than before. i took it into service cause the airintake sensor for the turbo went. the cars done 120,000km and the original mechanic i took it too was impressed with its overall condition. whats the damage on a replacement turbo and would it be advisable to get a bigger one? or am i going to open pandoras box by bolting a bigger Turbo.

thanks

Drew

[00drewski]

What they also do for an MOT on diesels to get it through the emissions is rev the crap out of it !!! its also known to be done, to get a car to go better ,and the customer says woow what you done she going so much better now !!!

There should be a warning given to customers that there is a slight chance that this can damage your engine when getting a diesel MOT,ed !!!

Keep on eye on your oil level , if its going down alot , then you may have a turbo about to go !!!

What happens is the turbo is fed with engine oil when the seals go in the turbo , the oil goes into the turbo and in the exhaust !!!!

This usually sucks the oil out of the engine and can cause alot of damage ,

But note that is a worse case scenario !!!

ill check the oil . ive done around 1000KM after the last service. is it possible that there was too much oil poured into the thing.?

thanks

look forward to more advice.

Drew

[MalcQV]

What they also do for an MOT on diesels to get it through the emissions is rev the crap out of it !!! its also known to be done, to get a car to go better ,and the customer says woow what you done she going so much better now !!!

That will explain that warning at the MOT station about diesels and you may be asked when the cam belt was last changed

[ini]

Too much oil is a very bad thing on the high compression TDI's.

Unbolt the EGR valve and check if there is a lot of oil present. (There should only be a light coating of oil/black crud.

The smoke is either excess oil, or the injector cleaner still burning off (amount of smoke depends on injector cleaner make, it is not normally black)

or

A small air leak in the boost side, causing the car to overfuel. (it thinks it is getting more air/boost)

It may not be a large enough leak to cause limp mode.

The mechanics may have 'accidentally' knocked one of the hoses (check all the hose/pipe joints are tight)