When I turn on my defrost it smells like exhaust

Tiny
ISAIAH S. STANLEY
  • MEMBER
  • 2014 CHEVROLET 1500
  • 4.3L
  • V6
  • 2WD
  • AUTOMATIC
  • 101,000 MILES
I don’t smell it while I am riding. What could cause this?
Do you
have the same problem?
Yes
No
Tuesday, October 29th, 2019 AT 5:20 PM

12 Replies

Tiny
STEVE W.
  • EXPERT
Welcome to 2CarPros. The first thing would be to track down if the smell is gasoline or exhaust. A gas smell could be from a leaking o-ring on an injector or fitting under the hood or it might be vapor from the EVAP vent valve.
Does it seem to smell more when it is hot outside? Any other times it smells?
Was this
answer
helpful?
Yes
No
Tuesday, October 29th, 2019 AT 6:06 PM
Tiny
ISAIAH S. STANLEY
  • MEMBER
To me it is more like a gas smell to me. I can smell it while sitting idle with the defrost on, but when I start move it seem to go away. When I first start my truck in the morning it stronger.

I only run my defrost when it seem to be cooler outside.
Was this
answer
helpful?
Yes
No
Tuesday, October 29th, 2019 AT 6:39 PM
Tiny
STEVE W.
  • EXPERT
Does it seem to be stronger after you fill up? Do you smell it outside the truck as you walk up to it? How about if you open the hood, smell it more then?
Was this
answer
helpful?
Yes
No
Tuesday, October 29th, 2019 AT 7:30 PM
Tiny
ISAIAH S. STANLEY
  • MEMBER
I cannot smell anything outside the truck. It s not stronger after I fill up. I will open the hood this morning to see if I can smell anything and let you know.

I did have it checked by the dealership once before and they didn t find anything, they said it could be my after market muffler. I had that replaced and I still smell it.
Was this
answer
helpful?
Yes
No
Wednesday, October 30th, 2019 AT 2:18 AM
Tiny
KEN
  • ADMIN
Hello,

This sounds like a classic fuel injector leak which can be tough to spot. With the engine running use a flashlight and check each injector for wet fuel. When you find it can you please shoot a quick video with your phone so we can see what's going on? That would be great. You can upload it here with your response.
Was this
answer
helpful?
Yes
No
Saturday, November 2nd, 2019 AT 1:09 PM
Tiny
STEVE W.
  • EXPERT
Did you get a chance to see if you could smell anything with the hood open? If so it would tie in with Kens post above.
Was this
answer
helpful?
Yes
No
Sunday, November 3rd, 2019 AT 4:12 PM
Tiny
ISAIAH S. STANLEY
  • MEMBER
Sorry, I did. I couldn t smell anything.
Was this
answer
helpful?
Yes
No
Sunday, November 3rd, 2019 AT 4:37 PM
Tiny
KEN
  • ADMIN
Did you check the injectors while the engine was running? Also look for a stain of past leaks as well.
Was this
answer
helpful?
Yes
No
Monday, November 4th, 2019 AT 12:01 PM
Tiny
STEVE W.
  • EXPERT
Okay, try this: Turn on the key don't start the engine, turn the defrost on, do you smell it now? Now start the engine, any smell? Cycle through heat, AC, defrost. Anything?
Was this
answer
helpful?
Yes
No
Tuesday, November 5th, 2019 AT 8:34 PM
Tiny
ISAIAH S. STANLEY
  • MEMBER
I tried it, and I can smell it with the engine not started and defrost on. I started the engine and switch between AC and heat it seem to go away.
Was this
answer
helpful?
Yes
No
Wednesday, November 6th, 2019 AT 3:00 AM
Tiny
ISAIAH S. STANLEY
  • MEMBER
Ken, I will check it this weekend.
Was this
answer
helpful?
Yes
No
Wednesday, November 6th, 2019 AT 3:01 AM
Tiny
STEVE W.
  • EXPERT
Okay, if you smell it when the engine is off but defrost on, it is possible it is mold/mildew growing in the HVAC unit. Somewhat a common issue with modern vehicles. First thing to check would be the cabin air filter. It is in the dash, hiding behind the lower glove box. To get to it you flip up the upper door, then flip the lower one down, remove the 4 screws that hold it in place and gently pull it out, there are two clips at each side so it may come out a bit hard. Behind it will be a door that folds down and inside that is the filter. It is an ACDelco CF188, Hastings AFC1626, Wix WP10129, NAPA FIL 230129, and a few others depending on where you look. I have seen them come out disgusting if people don't know they are there. While you are getting that pick up a can of vent deodorizer. The stuff I use is sold at the local dealer and is a spray foam, you basically shoot it into any opening for the heater you can find including the outside air inlet, it foams up and kills off anything living in the duct-work.
Was this
answer
helpful?
Yes
No
+1
Wednesday, November 6th, 2019 AT 4:02 AM

Please login or register to post a reply.

Sponsored links