The GMC Sierra, like its sister the Chevy Silverado, is a General Motors (GM) full-size pickup truck. Since truck owners haul cargo as well as passengers in their trucks, it's harder to keep odors from developing. Cleaning the fresh air vents on a regular basis helps rid your truck of odors.
Purchase a bottle of GM Vehicle Care Odor Eliminator. Dealers buy this product by the case and usually stock it for sale to their customers in a 16 oz. spray bottle. It's not available in stores, but you may be able to find it online.
Confirm that the air fan is off by getting in your truck and turning your Sierra on. Then, make sure there's ventilation in your truck by opening the front windows. After that, turn your Sierra off.
Spray the odor eliminator into all the inside vents in your GMC Sierra. Use one or two sprays in each of the vents. Spray down in the vent, not just in front of it.
Start your GMC Sierra and put the air fan on high cool. Don't use the air conditioning setting at this time though.
Go to the front of your truck after getting out and closing the door. Find the fresh air vent located under the cowl in your Sierra--you may have to open the hood to see it clearly. The cowl is in the area closest to the windshield at the base of your hood. Spray the vent 10 times with the odor eliminator.
Enter your Sierra after a minute and wipe away any excess formula that's coming out of the vents from where you sprayed the external fresh air vent.
See if there are any more odors coming from the vents. If there are, go back to the outside vent and spray it an additional five times.
Repeat Steps 6 and 7 until there aren't any odors in your GMC Sierra. Once accomplished, turn the air conditioning to the recirculation setting, close the windows, spray into the lower right instrument panel area three to five times.
Run your GMC Sierra for five to seven minutes. Then, turn your truck off and exit your vehicle.
Find the cabin air filter, if your GMC Sierra comes equipped with one. Replacing this filter helps eliminate odors. It's located either behind the glove compartment, under the dashboard or in the engine chamber.
