GDI Malibu Rollin Coal

[bumpasmerc]

Was kind of dodling along on a country road today when a late model Malibu closed in behind. He must have floored it to pass me. What surprised me was the large amount of very black smoke that spewed out of the exhaust. It continued until he was up to speed and backed off the throttle. It was easily as bad as an old pre-TDI VW.

I guess I just witnessed rich fuel ratio that produced soot and possibly fuel dilution of the oil. Makes me wonder if the recommendation to drive GDIs hard is valid.

 

[ls1mike]

Originally Posted By: bumpasmerc
Was kind of dodling along on a country road today when a late model Malibu closed in behind. He must have floored it to pass me. What surprised me was the large amount of very black smoke that spewed out of the exhaust. It continued until he was up to speed and backed off the throttle. It was easily as bad as an old pre-TDI VW.

I guess I just witnessed rich fuel ratio that produced soot and possibly fuel dilution of the oil. Makes me wonder if the recommendation to drive GDIs hard is valid.



I am pretty sure you need to open it up once in awhile. We have a 2.0 Turbo (LTG) Malibu and I haven't seen it like that, but I know they can if you don't lay into them once in a while.

 

[racin4ds]

Many vehicles will do that when they are never floored or ran hard. Its good to run an "Italian tune up" quite often to keep things clean.

 

[Delta]

See it all the time, especially when people flog it going up the mountain. I bet my GTI does it even though it gets run real good daily. Plenty of carbon deposits on the exhaust tips.

Now the S10 will be blue smoke, but, well yanno...

 

[KrisZ]

GDI engines do produce a much larger amount of soot than their port injected counterparts. Expect manufacturers to start putting in some sort of exhaust particulate filter on them once the emission regulations catch up.

 

[supton]

I've seen a number of vehicles do this. I don't think were GDI either. I think some of the high zoot engines run rich to avoid detonation, moreso on older models from ten or more years ago.

GDI though might be more prone to this, as I recall them having larger particulate matter emissions.

Also, what you might see is the accumulation of soot. They might not be running all that rich under WOT. Just that it's been driven very lightly long enough to get a good layer of soot in the system.

 

[bumpasmerc]

BTW the Malibu looked like a 2013 model thereabouts.

 

[nthach]

I think I saw a GTI or a A4 roll coal the other day ago, I've also seen sooty buildup on the rear end of Sonatas with GDI engines.

And while newer diesel engines are regulated under EPA2007/2010/2014 rules to reduce visible exhaust, I've seen buses roll coal. The transit agencies here installed a Cleaire Longview DPF/NOx trap device that injects extra diesel upstream of the DPF/cat stack and buses with those did have a small puff of black smoke when they pull away from a stop but they also rolled coal on the highway to clean themselves up.

 

[JTK]

I've noticed this quite a bit too on late model vehicles.

Always figured it was just due to the fuel mapping getting freaked out by drastic change it hasn't seen in awhile.

 

[HemiHawk]

Originally Posted By: Delta
See it all the time, especially when people flog it going up the mountain. I bet my GTI does it even though it gets run real good daily. Plenty of carbon deposits on the exhaust tips.

Now the S10 will be blue smoke, but, well yanno...

I've basically accepted that My GTIs polished tips are just black now. Cleaning them would be a never ending struggle

 

[VeryNoisyPoet]

My port injected turbo car runs rich in general and will give a puff of soot when I clear its throat up the on ramp after a few days putting around town. Never smokes for more than a couple seconds or so as far as I can tell looking at the rear dashcam footage.

Extended black smoke does sound like overfueling or poor combustion, even for a GDI. Catalytic converter can't be too happy about that.

Climbing mountain grades out west I saw some greyish smoke from other cars but the only one rolling coal was this older dump truck puffing like a steam train with the Detroit Diesel screaming its head off.

 

[pezzy669]

Any car whether GDI or port injection that are babied for long periods of time will dump soot when driven hard. Had a rental '17 Maxima (port injection) last month in Minnesota with ~4800 miles on the clock when I picked it up, first time I opened it up on the freeway to squirt from ~60-80 I left a nice cloud that was quite visible in the rear view mirror. Never did it again after that - figure it had been babied its entire 4800 mile life.

 

[dishdude]

These cars aren't blowing out any carbon! When you go WOT the mixture goes turns a bit rich and you get black smoke. I do not believe in the old ITU on fuel injected cars, maybe in the carb'd days but that's before my time.

 

[jakewells]

I use to have a older gmc truck with TBI that would puff a little black on hard acceleration. a good tune up and overhauling the TBI unit solved that problem.
Have not seen any new cars roll coal in my area only seen the newer diesel trucks roll coal.

 

[dogememe]

I rolled coal in my Suburban today

Something's wrong with it so it runs really rich and so I floored it right after a cold start and I got a cloud of blue and black smoke.

 

[CT8]

Originally Posted By: KrisZ
GDI engines do produce a much larger amount of soot than their port injected counterparts. Expect manufacturers to start putting in some sort of exhaust particulate filter on them once the emission regulations catch up.
Dual injection.