Name That Smell?

[deyomatic]

2005 Sierra, 4.3L, auto. 41,700 miles.

 

A few weeks ago I was driving this truck on the highway. Something happened ahead and traffic was stopped while sitting in traffic I could smell something that was kind of like hot brakes or burnt clutch. When I drove away the smell dissipated. I figured it was some other car. At the next stop light I smelled it again. The other car was not around. The smell followed me wherever I stopped. I assumed it was brake related so when I'd get out I'd sniff around the wheel wells but couldn't really smell it there. It was more of a general smell around the truck, but very faint. The following day it was there again. Both days were either raining, or intermittent drizzle.

The next day I opened the hood, noticed a burnt leaf on my exhaust manifold and removed it, and never smelled it again, until last night. I got a hint of it when I stopped at a red light but not again. It was raining again last night.

 

I'm wondering if it's related to the defogger or wipers, somehow, since right now the only consistency is the rain.

 

Does anyone have any clue what it might be?

 

Thanks.

[700 sportsman]

Have you did your brakes recently, you may have a stuck caliper?

[cerbomark]

My 08 Outback does that and I just got a recall on catilytic converter getting too hot cause of a ECM tuning issue.