A4 1.9 TDI (130) engine problems - please help

[Cue_Ball]

Hi there,

I recently bought a 2002 A4 1.9TDI (130) estate and its great I love it, it hasn't put a foot wrong until last night... The diesel level was low (just under quater of a tank) so I filled her up at my local garage (£60 worth) and drove it home. I went to go out in it last night and it started on the nose as normal but as soon as I went to pull off the drive the engine became erratic with the rev needle jumping up and down, there was no power at all and there was alot of white smoke coming from the exhaust which smelt very toxic. I double checked the reciept to make sure I had actually put in Diesel (just in case) but it definately says diesel on pump 1 etc. I thought I would leave it at idle to warm up the engine to see if that helped (she starts and idles perfectly). I then managed to pull out of the drive and drive her a little way but there's no power there as if the turbo isn't kicking in, then on occassion the turbo comes on and its all back to normal for a few gear changes then nothing again. I tried again this morning and the same thing only this time I cant seem to get enough power to even get her to move forward, it just cuts out now... Does anyone have any ideas? I am new here...

Thanks,

 

[fjtwelve]

Had same problem but black smoke, turned out to be N75 valve. See also thread on diesel forum about white smoke.

 

[Neil_S]

Sounds like it could be a vacuum hose or something near the EGR or one of those valves like the N75 (I had one go (think it was called the N18 solenoid) and a split vacuum hose and had all sorts of smoke and erratic RPMs and stalling).

Try pulling the hose out of the top of the EGR (the silver disc that shows through the engine cover at the top left).

Also try disconnect the MAF sensor (connector which connects to the air pipe going into the turbo), if it improves it could be the MAF, although when I had the vacuum hose problems, disconnecting improved the situation for me, but it wasn't a faulty MAF.

 

[Cue_Ball]

UPDATE ----

The garage (not Audi dealership) have read the codes from the ECU and most didn't make sense referring to temprature sensors, one code even referred to an engine mount for some reason. He said this may be because previous codes have not been cleared.

They seem to have cured the problem without any parts. He said they have cleaned the EGR and run some injector cleaner through it. They have also cleared the codes from the ECU. The only code that wont clear is the engine mount code apparently... Anyone know anything about this?

I not sure if what they have done hasn't just delayed the problem happening again but you never know.

 

[46TheDoctor]

Yes they have a Hydroelectric engine mount which is there to counteract vibrations from the engine, common as **** for failing but will not cause any running problems, im off to clean my egr and inlet manifold tomorrow before i get it REVO'd next week,YIPPEEEE Oh yea they cant clear the code cos the mount is still ********..

 

[Neil_S]

If it is a coolant temperature sender (common), you'll want to get this changed.

It's on the rear of the engine block, easier to get too if you take out the air filter and hose to the turbo.

You can do it without losing much coolant, I just topped mine up as I lost about a litre doing it.

Sensor was about £15.

 

[james0808]

I would pull the pipe off to see if they have actually cleaned the egr.
This is how much crap i cleaned out of mine.
Clicky

 

[Neil_S]

Good idea from James, I cleaned the EGR and intake manifold too, got a similar amount of crap out.

I found gunk to be superb when you've got the majority of the crap out to really bring it up clean.

 

[Cue_Ball]

UPDATE----

uess what... The garage haven't fixed the problem. I picked up the car on Friday and drove it the 4 miles home, it seemed to be fixed although the engine wasn't running quite right, I didn't use the car yesterday, I got in it this morning and guess what, its still doing it...

No idea whats going on now... I guess I'll have to take it to a diesel specialist...

 

[Cue_Ball]

UPDATE----

Now taken the car to the diesel specialists! They took the car into the garage, plugged it into the computer (shook their heads), took a ball bearing from their tool kit, put it in the EGR valve, gave me the keys back and said try that...

Its like the car has been given a new lease of life!! PERFECT!!

Why the last garage could work that out is beyond me...

All for £10 (or the cost of a round of beers for the mechanics)

I asked them about emmissions and was shown the readouts from an A4 prior to blanking the EGR and then afterwards, guess what - improved emmissions! I was then shown a torque and BHP graph, guess what improved torque and BHP!

Does anyone actually know why an EGR valve is put on cars in the first place?