Foul Odor 1999 Silverado

[gunnybob]

I have a 3/4 ton Silverado with 105k which has served me well. Last year on my return from Wyoming to Minnesota after the engine was good and warm, when ever let off on the gas to come to a stop, the cab would fill with a rotten stench. After venting the cab and back on the freeway it was not noticeable. I took it to a shop and the mechanic could find nothing wrong with it. He said it might have been bad gas. Because I winter in Florida, I did not drive it until this weekend when I went to Canada fishing. As soon as the truck was nice and hot the smell came back again when I backed off and came to a stop. It appears that the odor comes from the vents inside the truck as well as from under the hood. Is it the catalytic converter? Please help. It is hard to keep my dinner down when it backs up. Thanks, Gunnybob

[2000DV4.8]

Does it smell like sulfur/rotten eggs? If so, sniff the tailpipe with the truck running. If it stinks like all hell, it's a bad catalytic converter.

[bill190]

Just guessing...

 

Also the heater core can leak, then you get hot engine coolant/antifreeze steam inside the vents, which does not smell very good. Heat some in a used tin can and see if it smells the same? The symptoms of this are also the windshield steaming up with this steam and it is difficult to clean off. The heater core circulates hot engine coolant inside the A/C system to provide heating and it looks like a small radiator.

 

Also in rural areas, it is not uncommon for "critters" to get into vehicles. But I should think after a full winter, it would have dried up and the smell would have gone away?

[superjim]

My guess, at this point, is bad catalytic converter.

[Stylous]

Have you replaced the cabin filters? From cold to hot they can develop mold on them which then circulates through the vents as the air passes through.

 

S/b replaced every 15,000.

[txab]

Evil

 

Shrink your sig pic. It's larger than the allowable.