Revised: Burning smell after car climbs steep grade

This is a revised posting since my Toyota is a 1999, not 2000, as originally described: There is a burning smell when the car climbs a steep grade such as Waldo grade approach to Golden Gate Bridge in SF Bay Area - brought to mechanic twice and they can’t figure it out. Any ideas? Thanks!

Oil can leak onto the hot exhaust and burn. Burning oil smells like burning rubber to most people. Your ace(?) mechanic should look under the hood for oil leaks and the stains on the exhaust from burning oil.

This is a revised posting

Did you start a new thread, or replace the old one? I didn’t see another thread by you.

Is this a manual or automatic transmission? If manual, you might have a slipping clutch (clutch job: $$). If automatic, the tranny might be slipping (rebuild: $$$). Hope and pray that it’s merely oil dripping on the exhaust.

Thanks for the input. My mechanic did check for an oil leak the first time. Found the oil pan gasket slightly loose ( I did notice oil leak spots on ground under car). He tighten it, no new oil spots. But car still smelled going up hills. Had taken car in a second time and he found plastic bag. He removed that, but the smell is still there when climbing a hill.

My Nissan smells that way when I leave it in Overdrive and go up a long mountain grade. It is probably some oil burning off surfaces that normally do not get that hot. Try the test in a lower gear; the smell might disappear.