Audi A4 1.9Tdi (B6) Not idling (AWX Engine)
Discussion
Good day.
I am from South Africa and decided to join this forum because it seems to be the most active in responses and, from other threads I've read, the information makes more sense and is more topic rerlated.
I recently bought a 2002 Audi A4 (B6, AWX engine). Shortly after I bought the car I had trouble with ''rough'' idling when I start the car. It would idle very low for a few seconds, then pick up and idle normal (around 850rpm). When the rpm goes up to normal idling there is a cloud of black smoke coming from the exhaust. Smells like diesel smoke. No whit or blue smoke, only black smoke.
I took the car to a local Audi specialist (not a dealer). he did full diagnostics on the engine but could find no electrical fault. He checked the injectors and the readings were as follows (grams/stroke):
1 > 1.66
2 > 0.64
3 > 0.43
4 > -1.11
I was told that although 1 and 4 are higher that they are still within spec and that it could not be the reason for the ''rough'' idling. He checked various sensors to determine if any of them are faulty, but according to him all were fine. The final verdict was that it might be dirty injectors, so I used some diesel injector cleaner. That made no difference.
Two weeks or so back, the car would not idle at all. The car struggle to start when cold, and when it does start, it would idle ''rough'' for a few seconds, then pick up but as soon as it gets to 850 rpm it would die immediately. When I keep the rpm above 1000 there is no problem. When I drive on the highway there is no problem wit the car at all. Turbo still boosting at 2000 rpm, fuel consumption within 5-6l/100km. Only problem is that when I slow down and rpm goes below 2000, then I have no power. Acceleration is very sluggish until i reach 2000 rpm, then the turbo spool up and the car flies like a rocket.
Driving in town is different story. When I slow down to stop, the car would die as soon as the clutch is compressed. I have to start the car at every stop sign/traffic light. Pull away is very slow until I reach 2000 rpm.
I took the car back to the Audi specialist, this time he did full diagnostic and could only find a fault on the A/C (high pressure switch faulty). Nothing else.
No he says it might be injectors, or the High pressure diesel pump, or the Cylinder head wiring harness. He suggested that I start with the high pressure pump on the back of the cylinder head.
What I did notice today, when I start the car, and I ''nurse'' the idling around 1000 rpm, it would eventually idle without my foot on the accelerator. Why would that be? I have video clips if anyone wants to see what I'm talking about.
I've done some research, and on all the forums and posts I could find, the most common part is the injector wiring loom.
I need some guidance or assistance as to where to start and what else I can check. Self tests I could do to eliminate specific parts/sensors ect.
What I have done thus far:
> I have replaced the diesel filter with a DEKRA filter (only replacement filter I could get) - No change
> I have bypassed the diesel filter (supply from tank directly into high pressure diesel pump on cylinder head) - No change
> I have cleaned all the sensors I could find with Sensor cleaner - No change
> I have cleaned all the connectors with electric contact cleaner - No change
Where do I start?
I cannot afford to keep on replacing parts until , by luck, he replace the faulty part. I know injectors are very, very expensive, even recon injectors are an arm and a leg.
My next thought would be to remove the diesel pump in the tank and clean the pick up filter.
I will highly appreciate any assistance and guidance.
I am from South Africa and decided to join this forum because it seems to be the most active in responses and, from other threads I've read, the information makes more sense and is more topic rerlated.
I recently bought a 2002 Audi A4 (B6, AWX engine). Shortly after I bought the car I had trouble with ''rough'' idling when I start the car. It would idle very low for a few seconds, then pick up and idle normal (around 850rpm). When the rpm goes up to normal idling there is a cloud of black smoke coming from the exhaust. Smells like diesel smoke. No whit or blue smoke, only black smoke.
I took the car to a local Audi specialist (not a dealer). he did full diagnostics on the engine but could find no electrical fault. He checked the injectors and the readings were as follows (grams/stroke):
1 > 1.66
2 > 0.64
3 > 0.43
4 > -1.11
I was told that although 1 and 4 are higher that they are still within spec and that it could not be the reason for the ''rough'' idling. He checked various sensors to determine if any of them are faulty, but according to him all were fine. The final verdict was that it might be dirty injectors, so I used some diesel injector cleaner. That made no difference.
Two weeks or so back, the car would not idle at all. The car struggle to start when cold, and when it does start, it would idle ''rough'' for a few seconds, then pick up but as soon as it gets to 850 rpm it would die immediately. When I keep the rpm above 1000 there is no problem. When I drive on the highway there is no problem wit the car at all. Turbo still boosting at 2000 rpm, fuel consumption within 5-6l/100km. Only problem is that when I slow down and rpm goes below 2000, then I have no power. Acceleration is very sluggish until i reach 2000 rpm, then the turbo spool up and the car flies like a rocket.
Driving in town is different story. When I slow down to stop, the car would die as soon as the clutch is compressed. I have to start the car at every stop sign/traffic light. Pull away is very slow until I reach 2000 rpm.
I took the car back to the Audi specialist, this time he did full diagnostic and could only find a fault on the A/C (high pressure switch faulty). Nothing else.
No he says it might be injectors, or the High pressure diesel pump, or the Cylinder head wiring harness. He suggested that I start with the high pressure pump on the back of the cylinder head.
What I did notice today, when I start the car, and I ''nurse'' the idling around 1000 rpm, it would eventually idle without my foot on the accelerator. Why would that be? I have video clips if anyone wants to see what I'm talking about.
I've done some research, and on all the forums and posts I could find, the most common part is the injector wiring loom.
I need some guidance or assistance as to where to start and what else I can check. Self tests I could do to eliminate specific parts/sensors ect.
What I have done thus far:
> I have replaced the diesel filter with a DEKRA filter (only replacement filter I could get) - No change
> I have bypassed the diesel filter (supply from tank directly into high pressure diesel pump on cylinder head) - No change
> I have cleaned all the sensors I could find with Sensor cleaner - No change
> I have cleaned all the connectors with electric contact cleaner - No change
Where do I start?
I cannot afford to keep on replacing parts until , by luck, he replace the faulty part. I know injectors are very, very expensive, even recon injectors are an arm and a leg.
My next thought would be to remove the diesel pump in the tank and clean the pick up filter.
I will highly appreciate any assistance and guidance.
Nope not yet. Will give that a go over the weekend. Just watched a video clip on youtube about cleaning the EGR on a B6. Do you really have to clean the intake ports on the head as well, or will EGR only suffice?
Can I post the link to the video here?
Can I post the link to the video here?
Edited by Eastside_ZAR on Friday 4th January 10:57
You can just do the EGR as thats the main culprit however when I done mine I took off the inlet manifold as well and give it a jet wash. New gasket will be required if you do this though. It's all pretty straight forward and accessible on the B6. It made quite a difference to the running of mine.
It may be also worth buying some blanking plates off eBay for a few quid and blank off the EGR once its clean so it stays that way.
It may be also worth buying some blanking plates off eBay for a few quid and blank off the EGR once its clean so it stays that way.
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