Smokey Smokey Smokey '95 Audi A4 TDi | Technical matters | Back Room Forum

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Tue 16 Sep 2003 13:54

Smokey Smokey Smokey '95 Audi A4 TDi - tgmnewry

Any of you bright sparks on this site got any ideas on this one.?? My car is a 1995 Audi A4 1.9TDi with 130K. Smokes real bad. Ok i expect a bit of black smoke on hard acceleration but this is more or less constant. When cruising at 80 on the motorway there is a constant heavy plume obscuring the view of the car behind, and of course REAL embarrassing. Sometimes seems to clear, but gets worse particurly when going up hill when at times the car seems to go down on power for a second or two.

The car starts ok, has new injectors fitted (yes tried that first), and new fuel oil and air filters. The car has FSH and the engine is smooth enough. My source of diesel is OK. My mechanic says it MIGHT be the fuel pump, but at £600 to replace I would not want to go down this road until sure. The other possibility is the air flow sensor, though he claims if this was troublesome the car would hardly drive at all, and it does pull well most of the time.
Help or ideas would be Really Really appreciated!!!!!!

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Tue 16 Sep 2003 14:08

Smokey Smokey Smokey '95 Audi A4 TDi - Ivor E Tower

Hopefully a "real expert" will help you in due course but...
what colour is the smoke? If it is definitely black, it is almost certainly excess fuel. How is your fuel consumption? Noticed any increase?
If it's grey smoke it will be something different eg how is your coolant (radiator) level? Has that dropped?

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Tue 16 Sep 2003 14:49

Smokey Smokey Smokey '95 Audi A4 TDi - RichardW

I do not know the exact details of this engine, but I know it is direct injection, and pretty sure it is computer controlled. As Ivor says black smoke is overfuelling - since you have changed the air filter and injectors, I would first check to make sure none of the air hoses is kinked or has collapsed. Following that I would head for whatever air pressure / mass sensors the engine uses. I am pretty sure that you will find one of these is having a bit of a strop. You might consider taking it to a diesel injection specialist who are much better placed to diagnose these sort of problems.

RichardW

Is it illogical? It must be Citroen....

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Tue 16 Sep 2003 16:21

Smokey Smokey Smokey '95 Audi A4 TDi - tgmnewry

To Ivor and Richard, the smoke is black!! Really Black. The coolant is 100% and the engine is not using any/leaking any.

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Tue 16 Sep 2003 16:46

Smokey Smokey Smokey '95 Audi A4 TDi - Marcos{P}

We recently had an escort van at work with the same problem. It went to a diesel specialist and they did something with the ECU.
Works a treat now with only the usual amount of black smoke.
Only cost about £40.

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Mon 29 Sep 2003 12:27

Smokey Smokey Smokey '95 Audi A4 TDi - hm

Please excuse me, I do not wish to seem rude.

How long have you had the car? A stab in dark, but if you recently brought it did the previuos owner have it chipped?

These chips alter the mapping on the ECU, some of the cheaper analogue chips have a tendance of producing plently of black smoke the better digital chips reduce this smoke.

Stab in the dark, I just know a mate with a Golf 1.9TDI, goes like hell but you think she running on waste oil)

Laters

H

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Tue 16 Sep 2003 18:19

Smokey Smokey Smokey '95 Audi A4 TDi - AndyT

The EGR system on VW group diesels has been known to clog with various by-products from the engine. The inlet manifold gets gummed up with a black gooey substance and needs a strip down and clean.

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Fri 26 Sep 2003 12:31

Smokey Smokey Smokey '95 Audi A4 TDi - tgmnewry

Any independant specialists that I contacted advised me to contact an Audi Dealer. And my Audi dealer advised me to go to an independant specialist, telling me there were practically no electronic tests they could do giving the age of the car!! Talk about going in circles!!

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Fri 26 Sep 2003 21:31

Smokey Smokey Smokey '95 Audi A4 TDi - Cymro Arall

Had same trouble with my 1.9tdi. It was the turbo. Got shot of it. R.I.P.

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Fri 26 Sep 2003 22:02

Smokey Smokey Smokey '95 Audi A4 TDi - DL

Not really the answer we were after!

I'd take the EGR valve apart and clean it, see what transpires.

Other than that, I'd go for the Mass Airflow sensor, but then you're into serious wonga territory...so perhaps a Bosch Diesel Specialist it is then............

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