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jd31 10-15-2012 10:33 PM

white smoke from exhaust and horrible gas mileage
 
Ugh. So my new Overland (5.7 hemi with 500 miles) is already having problems. Twice on start up it coughed a big white cloud of smoke out the exhaust. It was a cold start and my car was on an incline -- another thread indicated that parking on an include tends to provoke the issue.

I don't know if it's related but I'm also getting horrible gas mileage. On my first tank I averaged 10 mpg and on this second tank, it looks like I'll do worse at about about 8 mpg. Granted I have a lot of stop lights around my neighborhood and some hills, but boy is this bad fuel economy. I don't drive with a lead foot and am very conscious about keeping the RPM's low -- always aiming for ECO mode. I have an appointment with the dealer this Wednesday but from reading other threads it appears most have taken theirs to the dealer to no avail. Pretty frustrating...looks like I'll be ponying up for the unlimited extending warranty.

berk483 10-15-2012 10:53 PM

Re: white smoke from exhaust and horrible gas mileage
 
What grade of fuel are you using? I routinely get 15-17 on country roads/town and easily 19-20 on the highway. Are you relying on the EVIC for your MPG or are you hand calculating it? The white smoke thing appears to be a hit or miss problem. I personally don't have that issue and I park nose up most times and remote start to make sure I don't see a bunch of smoke as I walk up to the vehicle.

jd31 10-15-2012 11:09 PM

Re: white smoke from exhaust and horrible gas mileage
 
Quote:

Originally Posted by berk483 (Post 697438)
What grade of fuel are you using? I routinely get 15-17 on country roads/town and easily 19-20 on the highway. Are you relying on the EVIC for your MPG or are you hand calculating it? The white smoke thing appears to be a hit or miss problem. I personally don't have that issue and I park nose up most times and remote start to make sure I don't see a bunch of smoke as I walk up to the vehicle.

For both tanks I used 89 octane from Mobile. What type of fuel do you use?

And I hand calculated...didn't use the EVIC.

berk483 10-16-2012 12:08 AM

Re: white smoke from exhaust and horrible gas mileage
 
Hmm, I normally run Shell 89 but I can't see that making that much of a difference. I would definitely check with the dealership about your fuel consumption. As far as the smoke goes, I don't think there is a definitive 'fix' for it and unless you see heavy oil consumption between changes I wouldn't worry too much about that. I guess try a couple more tanks of gas and see if your mileage comes out any different. I hand calulate mine and it's normaly 17.XXX depending on how much highway I drive.

bill_de 10-16-2012 05:45 AM

Re: white smoke from exhaust and horrible gas mileage
 
White smoke is generally water vapor. If it coughed it out, that might be an issue. It's not uncommon for condensation to form in the exhaust system as things cool overnight after a humid day. At certain times of year I get white smoke for the first mile or two. This is with my current MDX, my previous Jeep, and my TrailBlazers before that.

jd31 10-16-2012 11:02 AM

Re: white smoke from exhaust and horrible gas mileage
 
That's reassuring and I hope it is benign. The first time it happened I figured it was probably water vapor but so I didn't pay too much attention. But the second time it happened I felt like it was too much substance to be vapor. It practically enveloped half of the car. I didn't smell anything strong though...

peckmv 10-16-2012 11:33 AM

Re: white smoke from exhaust and horrible gas mileage
 
Its not water vapor. My smokes at startup year round. It only happens when on a slight incline and it envelopes the entire car. Its a big cloud of bluish white smoke that only lasts for about 10 seconds. Water vapor will lasts longer. Jeep knows about this and its a bad design of the oil pan. The sump is reversed so the deep part of the pan is forward vs rearward. On an incline the oil pools in the rear of the pan and oil seeps past the rings so at startup that oil burns off causing the smoke. There was talk of a fix but so far nothing.

2012 Summit 10-16-2012 11:44 AM

Re: white smoke from exhaust and horrible gas mileage
 
Quote:

Originally Posted by peckmv (Post 697619)
Its not water vapor. My smokes at startup year round. It only happens when on a slight incline and it envelopes the entire car. Its a big cloud of bluish white smoke that only lasts for about 10 seconds. Water vapor will lasts longer. Jeep knows about this and its a bad design of the oil pan. The sump is reversed so the deep part of the pan is forward vs rearward. On an incline the oil pools in the rear of the pan and oil seeps past the rings so at startup that oil burns off causing the smoke. There was talk of a fix but so far nothing.

I'm surprised to hear oil, in the pan, can seep past the piston rings. How steep of an incline is required for this to happen?

Thanks in advance.

jd31 10-16-2012 11:49 AM

Re: white smoke from exhaust and horrible gas mileage
 
Quote:

Originally Posted by peckmv (Post 697619)
Its not water vapor. My smokes at startup year round. It only happens when on a slight incline and it envelopes the entire car. Its a big cloud of bluish white smoke that only lasts for about 10 seconds. Water vapor will lasts longer. Jeep knows about this and its a bad design of the oil pan. The sump is reversed so the deep part of the pan is forward vs rearward. On an incline the oil pools in the rear of the pan and oil seeps past the rings so at startup that oil burns off causing the smoke. There was talk of a fix but so far nothing.

I see...so does this pose a threat to the integrity of the vehicle or it just a nuisance?

peckmv 10-16-2012 12:45 PM

Re: white smoke from exhaust and horrible gas mileage
 
Quote:

Originally Posted by 2012 Summit (Post 697626)
I'm surprised to hear oil, in the pan, can seep past the piston rings. How steep of an incline is required for this to happen?

Thanks in advance.

Its a slight incline like about 10 deg. Since the rings don't totally seal and the 5.7 uses a thinner oil, it only takes a small amount to seep past the rings to get smoke. The JGC does have to sit off for a bit of time for this to occur. This is also just a theory, but so far the only one that makes any sense to me.

peckmv 10-16-2012 12:49 PM

Re: white smoke from exhaust and horrible gas mileage
 
Quote:

Originally Posted by jd31 (Post 697631)
I see...so does this pose a threat to the integrity of the vehicle or it just a nuisance?

It doesn't seem to effect it any. I have 14k miles on mine and it still does it. The hemi does have to have the plugs changed at 30k so when I take them out I can inspect them for any oil fouling, or see if it just burns it off.

jd31 10-17-2012 03:23 PM

Re: white smoke from exhaust and horrible gas mileage
 
Dropped her off at the dealer today. We'll see what they say. I'm not overly optimistic based on what the guy at the service desk said this morning. Basically, without seeing the car, said it probably is due to something that happens in transit...something about a film that builds up. It made absolutely no sense and I told him it's a known, documented issue that a simple Google search would reveal.

I'll let you know that this dealer says.


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