2003 Golf - Undetactable engine problem - running rough

[GolfInfo]

VW Golf running rough.

Hi there,

I have a VW Golf 2003 sport 2.0.

I have had this problem for more than an year now, and has really broken my trust in VW's.

My mechanic has not been able to solve this and I am trying to find who can or atleast some guidance.

This does not happen all the time, but mostly when the winter kicks in, I feel.

Basically the problem is, the engine is running rough. But to explain in detail, there is a lot of black smoke being puffed out and it smells like sulfur, the engine kinda of misses and feels like it's going to stop, but never does. On Idle, the miles per liter display shows 3.4 to 4.0. Per 100 litre as opposed to 1.2 to 1.4 when nothing is wrong. The computer also does not give any error codes. Once it did say that one of the pistons where not working and that's why I replace the plugs. The problem came back after a few months though.

Fixes:
I have replaced plugs, ignition cables, sensors O2 (the one next to the airfilter), temp sensor, air filter. I have done a throtle body clean a couple of times.... and my mechanic has basically run out of options. So I am asking someone in the forum to guide me to a better vw mechanic or some ideas as to what I should do apart from selling this. I am hoping it's not the central computer thats busted.

On a side note - there is a quick fix for this that my mechanic does. He would reset the engine computer each time this happens and then it would be good for a couple of days or even months. I did a reset a few days ago becasue it started running rough but, this time it went bad again in about an hour.

I live in melbourne south. Any good vw mechanics for this sort in that area.

Also I havent been to the dealer, and that would be the last resort, which I am very close to doing.

If not for this the car is really great. Any help please.

Thanks

K

[dubbed]

Could be the MAF or the part that sits on the battery (mind has gone blank).

Definitely take it to a VW specialist though - try Volkspower in Burwood. They know their stuff inside out and have always sort me out quick.

[grtuned]

I suspect you check the wiring from the coolant temp sensor to the ecu and the wires from 02 sensor to the ecu. Seems to me your having a mixture issue with the info you have given if you have replaced most of the items which control mixture. After wiring check possibly ECU faulty???


Sent from my iPhone using my fingers.

[MCiN7]

Not sure if it's the same as a few other engines: Fuel pressure regulator?
If faulty, can leak extra fuel into the intake through the return line at the side/back of the regulator.

But again, that's even if it returns to the intake.

Quick test is to remove the return line and see if fuel is spitting out.

[kaanage]

sensors O2 (the one next to the airfilter),

There should be another one after the catalytic converter. Did that get changed too?
http://www.vwwatercooled.org.au/foru...nay-38433.html

I had a car that behaved like yours and was continually fed new coil packs by the dealer service center until they finally diagnosed it as the lambda sensor but only AFTER the warranty had expired.

[GolfInfo]

Hi all thanks for all the information provided. After reading all the last post, I think I have got something wrong here. It was the Air Flow meter (MAS Sensor) that was replaced. So it's not actually the O2 sensors. Ok so do you reckon, I should get the O2 sensors replaced. What would be a good place to get that done. Some mentioned a place in Burwood. How is Volkscare in Bronia, is that a good place for this sort of work. Do you think I can replace the O2 sensor my self.
Let me know.
Thanks K

---------- Post added at 12:15 AM ---------- Previous post was at 12:11 AM ----------

Yes it's something to do with the mixture... there so much fuel being drained when this happens... and smelll bad too....
The MAF was replace but not the O2 sensor, I got it wrong before.

---------- Post added at 01:44 PM ---------- Previous post was at 12:15 AM ----------

There should be another one after the catalytic converter. Did that get changed too?
http://www.vwwatercooled.org.au/foru...nay-38433.html

I had a car that behaved like yours and was continually fed new coil packs by the dealer service center until they finally diagnosed it as the lambda sensor but only AFTER the warranty had expired.

Hi all thanks for all the information provided. After reading all the last post, I think I have got something wrong here. It was the Air Flow meter (MAS Sensor) that was replaced. So it's not actually the O2 sensors. Ok so do you reckon, I should get the O2 sensors replaced. What would be a good place to get that done. Some mentioned a place in Burwood. How is Volkscare in Bronia, is that a good place for this sort of work. Do you think I can replace the O2 sensor my self.
Let me know.
Thanks K

[Bug_racer]

Im pretty sure you will be only running 1 4 wire Lambda probe
Its narrowband so you wont have 2 sensors

[Jmac]

Some APK motors did run the 2 probes but most delivered in Oz only had the one, and if it were running 2 the aft one wouldnt be causing this. Anyway the black smoke is way too much fuel, your guy needs to read what the ecu is receiving , what the coolant temp is telling the ecu, is it hot , cold or all of the time??? cold forget the o2 sensor, hot then yes have a think about that, he needs to check if the 02 sensor is cycling and whilst we are talking about 02 sensors was it an OEm one or an aftermarket one?? been stung a few times with "new" sensors even from my supplier and ended up biting the bullet and buying from the dealer and it fixed it. I trust the vac line to the fuel reg is whole? if it has a leak then the fuel rail sits at full pressure all of the time. Sometimes you have to forget scanners as they are not so quick, if your guy has an oscilloscope then the maf and 02 can be scoped if need be.
Good luck with it

Jmac