Hey guys!

Before I crack on a few stats to the car:

1. it is a 1997 built Euro 2 3.2l (means only one upstream O2 sensor/bank)
2. the exhaust is modded but that shouldn't matter
3. the cats have a perfect conversion rate
4. emissions test was done yesterday as well, nothing weird around it

As I did a quick video to cover the "reincarnation" of my old XJ8, I noticed that there are some "black soot" clouds coming out at higher rpm... I know that Euro 2 emission cars aren't the cleanest compared to the latest Euro 6 pollution wonders (which emit more soot than the old diesels of the 80ies) but I find the black "rich mixture" fuel quite, well, dirty!? Can I say it like that? Is this NORMAL?


Some cars will really chuck in loads of fuel at higher rpm in order to keep the engine "safe" (prevent it from overheating etc.), but is this also the case in the X308? No fault codes saved nor anything weirdly working...

If it is normal, well, I'll have to live with it Never noticed it before...

Cheers

Damien

(currently more curious regarding his car as it has just come back to life)

 

I get a small burst when I get on my SC from a dead stop. What do you get when you run your finger around the tailpipe? Is it clean,....a dry black residue,....or oily/sooty?

 

I get a dry, black residue. No oil. Is probably just soot.

 

What are your fuel trims saying? Could be an unmetered air leak and the ECU is adding juice, or your MAF is dirty. A couple of quick jobs there.

 

Hey Sean,

I'll have to read them out when the car is back here again... But IIRC they were around -14% (lambda adaption) last year. They got better along the lines... But I haven't checked since I replaced the sonds/O2 sensors...

I don't think I have a vacume leak, at least I can't remember hissing or something like that... Though I will check with some fluid to see if anything gets better/worse.

 

It could also be revving the bollocks off it! at high rpm the engine is fully advanced so fuel enrichment is on.
I learnt long ago revving big engines didn't do them any favours.

 

Well, it wasn't just for a video... I was giving it the wellies as it had some 'oddity' with the idle, where it would stumble and then cough a couple of times. But after that 'cough' it was better. Wouldn't surprise me if the engine wasn't 'calibrated' (if you know what I mean) and needed to be blown clear of all soot etc.

 

Dry is good, ...do you smell excess fuel per chance from the exhaust? When was the last time you did plugs? These ignitions are very good, but that doesn't curtail them from fouling a plug....especially if its advancing like Sean said. In either case, its a somewhat quick check.

 

Hey there,

feel all dry. The plugs are about a year old and had around 18k miles on them. The coils work wonderfully.

But it is current speculation. I'll get my tester on it...