Smokey exhaust

[steviegtr]

Hi all. Would any tech buffs like to comment on my cars unusual amount of smoke from the exhaust. 2017 V8R AWD. under 18000 miles serviced at main dealer last week with a clean bill of health. The car drives perfectly & does not give any smoke from exhaust under everyday use. However & please don't shoot me down any of you green guys, but I do like to do the odd launch. So sport mode on, Dynamic selected & either paddle the gears or just leave it alone. The amount of grey smoke (Unburnt fuel) out of the back could power a small village. It has happened on a couple of occasions now but not always. Although it is not something I have done everyday, just a few times. Fuel economy has dropped from long run 25 last week to 17.5 now , so think that's about right. Not using water or any oil so from my experience with fast cars it is unburnt fuel, which would indicate it is rich but not burning it. My Skyline often did this, but that was stupidly modified & as far as I know this car is standard. The only thing was when I bought this car privately from a petrol head who has a lot of exotica in his possession, he told me it was reprogrammed to 575bhp. I took this with a pinch of salt as he seemed to be exaggerating. Not sure now. I do have an enquiry in with David Appleby engineering so maybe I will find out. Any input guys as I know a few of you are quite genned up on the Jag's

[Tel]

Black smoke; at WOT is absolutely fine and it shows a little unburnt/rich mixture. To be expected even more so if you suspect the car is tuned.

Grey smoke; tells me the cats are choked and need a good clearout...
Essentially you have to get the cats pretty darn (red) hot to burn the crap off of the internals. Dual carriageway and get the engine under load, keeping it in manual (as the ZF changes up early), thus keeping the revs higher than normal...say 2500 - 3K for 5- 10 minutes should do the trick..you can test to see if they have cleared by accelerating at WOT and looking in the mirror for any grey.

Excessive blue smoke though is not good.
When does it emit blue smoke? at startup, when running?
Worn internals, which I very much doubt on such a new engine, will allow engine oil to enter the combustion chamber and be burnt off which gives blue smoke. The other cause is from the supercharger. Within the 'snout' is a small reservoir of oil that's supposedly filled for life...the shaft seals have bean known to allow some oil to pass.

Ideally if you could post a video, that would help a great deal.

[scm]

Excessive blue smoke though is not good.
When does it emit blue smoke? at startup, when running?

Er, I couldn't see any mention of blue smoke in the OP?

[steviegtr]

Hi tel. No it's not burning oil. What you said made some sense for the following reasons. When I bought the car, after 1 week I had it's 2nd 2 year service done at 17500 miles. 2 days later I got an engine orange mil light on dash. I called assist. They could not come till following morning. When the guy was due to arrive I took car from garage & mil light went out. Never to return so far. The assist guy put obd2 reader on & it showed a pending No 1 Catalyst. He asked if car had been stood. I explained I had just bought car & it had only done 2000miles in the last year. He said basically what you are saying. Strangely since my post I have been out this evening in the car & repeated the launch from 0 to maybe 60'ish There was no smoke whatsoever. I will do as you suggest & give it a run & keep in lower gear. Thanks for help. P.S the acceleration on this thing is mental. I swear it is quicker off the mark than my Skyline & that was stupid power. The best run on rolling road was 680. But I guess manual gearbox & turbo lag against 8 speed dsg & supercharger it would be quicker off the mark. I still cannot get out of the habit of changing down going through bridges. Am retired but still cannot grow up, haha.

[scm]

Is the ZF a DSG?

[steviegtr]

It works pretty much the same. Very quick gearchange. Some say not as quick as some DSG's but still pretty quick. They must have speeded the software as the Evoque we had was much slower to respond although that was the 9 speed version & probably different internals. While on the subject I also discovered the magic revs to change up gear to get the Audi type explosion in the exhaust. 3800 to 4000 gives a lovely Boof sound.

[Tel]

Excessive blue smoke though is not good.
When does it emit blue smoke? at startup, when running?

Er, I couldn't see any mention of blue smoke in the OP?

Holy, moly, and that's before any G & T's
Early dementure I guess!

[davidd]

It's not as quick as a dsg. It is the one thing I really miss from my old GTR, the brutally quick gear shifts.

As for the power claims, I wouldn't be surprised if it was making 575, I'd expect a little variation on the outputs of the engines and I would hope that Jaguars claims would be the base standard. Have many had them on rolling roads?

Back to the smoke, I always thought a bit of a thrashing was good for a car.

D