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Natural gas smell in cab

HyperX

By HyperX
in Troubleshooting & Recalls

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HyperX Enthusiast

HyperX

Posted
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I just noticed that my 2016 Sierra Denali with the 6.2 engine has a gas smell inside the cab. Not fuel but it smells like natural gas. Truck only has 4800 miles and I just noticed it this week. This happens when the truck reaches normal operating temperature. Ideas?

ChrisTronyxYocum Enthusiast

ChrisTronyxYocum

Posted
Posted

I'm not a mechanic by any stretch of the imagination, nor have I had my truck for very long, but I'd have to guess that it's something with it being new possibly burning off or heating up enough to generate an odor. If anything, contact your dealer if you haven't already, or if no one here can provide any better insight. Just my $0.02.

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HyperX Enthusiast

HyperX

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Thanks Chris - I will schedule a trip to dealer it's just I know these types of issues are hard to replicate and or diagnose. Hoping to find someone with same issues.

pm26 Senior Enthusiast

pm26

Posted
Posted

It could possibly be a leak in the exhaust system somewhere. Maybe someone failed to tighten some exhaust clamp or bolts.

glcbn Enthusiast

glcbn

Posted
Posted

It could possibly be a leak in the exhaust system somewhere. Maybe someone failed to tighten some exhaust clamp or bolts.

 

Could very well be something with exhaust. It does have that funky smell due to the converters.

waumo1 Enthusiast

waumo1

Posted
Posted

As stated by others, it is probably exhaust. Rotten egg smell from exhaust/catalytic converters is likely, it used to be more common than today.

 

The "natural gas" smell is added mercaptan to give natural gas a skunk or rotten egg smell.

paumat Enthusiast

paumat

Posted
Posted

I just noticed that my 2016 Sierra Denali with the 6.2 engine has a gas smell inside the cab. Not fuel but it smells like natural gas. Truck only has 4800 miles and I just noticed it this week. This happens when the truck reaches normal operating temperature. Ideas?

is it only when you have the upper vents blowing air (AC not on)? Mine smells like hot motor oil but I don't have any oil level issues and it's only when the upper vents are on.

HyperX Enthusiast

HyperX

Posted
  • Author
Posted

is it only when you have the upper vents blowing air (AC not on)? Mine smells like hot motor oil but I don't have any oil level issues and it's only when the upper vents are on.

 

Yes! Only when AC is on. and they just changed my oil for the first time two weeks ago. It started around then. You think there is some residual oil burning off?

paumat Enthusiast

paumat

Posted
Posted

 

Yes! Only when AC is on. and they just changed my oil for the first time two weeks ago. It started around then. You think there is some residual oil burning off?

not sure. mine only does it when the AC is off but vent fan is on, blowing in hot outside air. I don't know what it is but it's been doing it for since new when it's hot out. I have 12000 miles on mine. Maybe whoever assembled the blower motor over-lubed it.

pm26 Senior Enthusiast

pm26

Posted
Posted (edited)

not sure. mine only does it when the AC is off but vent fan is on, blowing in hot outside air. I don't know what it is but it's been doing it for since new when it's hot out. I have 12000 miles on mine. Maybe whoever assembled the blower motor over-lubed it.

I believe blower motors have sealed bearings, I doubt someone just liberally pumped grease into them through some grease fittings and made a mess.

Edited by pm26
HyperX Enthusiast

HyperX

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For those that care here is the update. The dealer said the differential fluid is overheating and thus creating the smell. It is because some bearing is causing some issue. This is the third truck they saw this happen to. I got a loaner. They said GM is aware of issue and TSB may be around the corner. I will post the entire ticket up here once they are done with it.

Edited by HyperX
paumat Enthusiast

paumat

Posted
Posted

For those that care here is the update. The dealer said the differential fluid is overheating and thus creating the smell. It is because some bearing is causing some issue. This is the third truck they saw this happen to. I got a loaner. They said GM is aware of issue and TSB may be around the corner. I will post the entire ticket up here once they are done with it.

could you smell it outside the truck or only through the HVAC system?

HyperX Enthusiast

HyperX

Posted
  • Author
Posted

could you smell it outside the truck or only through the HVAC system?

 

 

Outside as well - you have to pop open the hood and the smell is on the drivers side forward area. Very pronounced.

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