newbie question

m40rcd

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I've go a 2002 audi a4 tdi 130bhp 96kw, with FASH.

It was 'chipped' by the last owner (a plug in, is all it was described as) at around 75,000 miles and is currently at 90,000 miles, but chucks out masses of black smoke. When it went in for the last service in audi i asked if this was normal and the guy said it was normal, but i've never seen a car put out so much 'soot'. I assumed this is unburnt fuel, but with it being so economic i'm confused. my last car was a 306 diesel (non turbo) which was really good on fuel but really slow. but the audi seems to be amazingly quick yet has better economy, doing 60+ mpg on a run?

Should i be concerned?
 
add a bottle of forte cleaner to the dregs in a nearly empty tank - better still add it neat to the fuel filter cannister.

Also 'remaps' will make diesels smoke a bit more. Maybe its a poor quality one?
paul
 
Great cheers, i will do that this weekend cos i'm driving to rhyl. Car is ridiculously quick, but its something thats bugging me. It was a £200 remap i'm sure.


thanks
 
i used the forte fuel system cleaning stuff on my last car at 84k and what a difference ! felt loads better
 
I'll definately get some tomorrow, cheers

If the 'remap' wasn't working correctly would this show in the mpg?
 
There are other causes for black smoke in diesels, eg MAF sensor, EGR valve, split hoses to & from these items. Have a look under the bonnet and the small hoses going about these items looking for cracks and/or leaks. Also disconnect the MAF & see if that changes things, and then also the EGR. Vagcom would also help dignose this of course. Cleaners have had mixed reviews, they do help to some extent in a sooted up engine but if you've got a lot of smoke its more likely to be something other than carbon build up. Non of the other faults i've mentioned will affect performance by the way.
 
Nickynibbles said:
There are other causes for black smoke in diesels, eg MAF sensor, EGR valve, split hoses to & from these items. Have a look under the bonnet and the small hoses going about these items looking for cracks and/or leaks. Also disconnect the MAF & see if that changes things, and then also the EGR. Vagcom would also help dignose this of course. Cleaners have had mixed reviews, they do help to some extent in a sooted up engine but if you've got a lot of smoke its more likely to be something other than carbon build up. Non of the other faults i've mentioned will affect performance by the way.

agreed. In the past (alfa 156 jtd) I have also cleaned out the intercooler with gunk and run hose for 20 mins, then dried out with g/fs hairdryer (it went pop) and cleaned pipes too. What a difference!!!! Oh, split intercooler pipes can also cause smoke! Either side of turbo too.
 
Cheers guys

Audi told me i got a leaking EGR valve? is this a possible cause then?
 
m40rcd said:
Cheers guys

Audi told me i got a leaking EGR valve? is this a possible cause then?

Yes! Check the hoses in & around the valve for splits. You can remove the EGR valve completely & block over the hole as a test to see if its actually the valve causing the smoke. Obviously the smoke would pretty much go if it was!
 
I'm not very mechanically minded so its going into audi a week saturday to be looked at. EGR valve will definately be changed. Cheers guys
 
My car just comeback from audi.

Egr valve was clogged and stinking so it has been cleaned and refitted, now there is not an ounce ofsmoke,i'm well impressed. Cheers guys
 
i found it - its at the back on the left side of the engine as you are looking from the front. It is silver with a vacuum pipe going into it. its just above the exhaust manifold and indeed runs off that.
P
 

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