Exhaust Smoke

[jeremyi]

Hi Folks,

I have been a longtime Peugeot 306 owner, now looking for change. I have been looking at a 2004 Gen 4 Golf 2.0l Sport.

After bringing it to the dealers attention that the car was blowing black smoke, they say they replaced the oxygen sensor. On re-inspection, from a stone cold start, it was still blowing some black smoke (now far less obvious). Some feedback I have had suggests that fuel could be leaking in to something or a possible computer problem, or that the fuel mix is simply too rich or lean. The dealer insists it needs nothing more than a good drive and that there is nothing wrong with it.

Does the black smoke suggest a problem that makes the car a lemon? Its done 70,000k's, is very straight, one owner, full VW service history and serviced a regular intervals.

I would appreciate some further advice.

Thanks,

Jeremy

[Cam]

Hey Jeremy,

What sort of fuel are you using in it?
Are you using premium?

Doesn't make it a lemon, there will be an explanation behind the problem.
:)

It would be good to run a scan with VCDS (VW diagnostic tool) to see any fault codes it brings up. Perhaps one of the Melbourne dubbers on the site might be able to help you out.
If you've had it into the dealer any big problems would have shown up in their logs. So hopefully this is a good thing. Alternatively perhaps get it looked at in a different VW dealership to get a second opinion.

There is a decent VW/Euro specialist workshop in Melbourne somewhere but I can't remember the name of the place. I'd be more inclined to take it here than a dealership.
:)

[Justin Fox]

Hey Jeremy. As I understand it: Blue smoke at start-up indicates deadly problems but black smoke suggests that the car is running rich (excess fuel is somehow entering the cylinder area and it's not being burned off completely).

The feedback you got on something leaking (a leaky fuel injector?) or a faulty engine computer/computer sensor could be spot on. Could even be a faulty fuel pump? Ultimately I'd suggest getting a trusted mechanic to look at the car.

EDIT: Spot on Cam the VW diagnostic tool is awesome. Dedy my mechanic plugged that into the VW I was about to buy and I was impressed with the detailed info it brought up on the cars history.

[Cam]

I've got a rosstech VCDS cable and I couldn't live with out it.
Best money I've spent on something diagnostics related. It does everything!
:)

If I was close to you Jeremy I'd offer to do a scan but there are members down in Vic that may be able to help you out.

Not sure if you have heard of Volkspower but are they anywhere near you?
http://volkspower.com.au//

Located in Burwood. I've spoken to Dean there before and he was excellent. Lot of people highly recommend them.

Regarding black smoke, I've got the same problem with my brothers SR2 2001 Laser. It smells like its running very rich (very fumey as well)

Took it into our local ford dealer and they said it was to do with the extractors and sports exhaust we had installed. Took it back to the exhaust workshop and ofcourse they deny any problems, but they did tell us they had to make some adjustments to the cat converter to fit the extractors. So thats possibly why we're encountering problems. Not sure if the cat converter would be whats causing your issue but perhaps something to consider?

[Jethro41]

I owned a MkIV 2 litre Sport prior to owning Gretel... I run it on 98 and it blew black smoke from day 1...especially if I tromped it.

I thought I had a real problem until I saw the amount of black smoke my brother's brand new 325 blew.

I did speak to the dealer about it, and they done their thing and told me it was normal.

Never had one issue with that MKIV, good car from day 1...perfect car when I sold her 2.5 years later. (in fact both my MKIV's were great cars)

I'm also told that Gretel blows a bit of black smoke when I get under it as well.