Burning Plastic Smell

[alethal]

The Car: 2006 Lexus LX470, ~120k miles, timing belt done, all other scheduled maintenance done.
The Problem: Wife is driving it today, gets home and says "It smells a little like burnt plastic." My sense of smell isn't the greatest but I detect a faint odor of what I associate with burning plastic, not rubber. Her sense of smell is much better, thinks is coming from the radiator area. I look at the fan, tubes, pipes etc, don't see anything. Coolant is full. I go back inside and close the garage and when I go back out 10 minutes later the smell is very strong. Definately something plastic burned/melted. I can't see anything.

Any suggestions?

CEL did not come on.
Only light on is the TPMS, been on for a few days, blinking so I think I need new sensors.

I can probably take it to the dealership or a local shop that does a lot of landcruiser work on Monday. I'm not what we would call a "wrencher"


Update: While no mechanic, I opened the hood, turned the truck on, rev'd it in neutral, could not get any additional smell, checked under-carriage, no stuck plastic bag (A suggestion from a previous thread) Going to go for a little drive (To the lindt chocolate store, if there is a local who knows my problem there could be some headed your way).

 

[alethal]

Update 2: drove 10 miles at speeds up to 80 and no smell. I've not got the foggiest idea.

 

[LEX]

Look around the manifolds and check to see if any hoses/lines came loose from clips that caused them to touch. Take a good look at the battery terminals, as well.

 

[TheForger]

Do you have the plastic engine cover on? It may be coming in contact with the manifold somewhere and melting it. Also check your exhaust pipe. My father drove over a plastic Walmart bag a few years back in his Camry and it stuck to his exhaust causing the smell of burnt plastic to seep into the cab.

 

[2001LC]

Rodent in engine valley perhaps, cook to d$%th and nothing left!

 

[bctlex]

Rodent in engine valley perhaps, cook to d$%th and nothing left!

LMAO... I would not want to smell or clean this!

 

[04UZJ100]

Did she ride the brakes

 

[Sandroad]

I'm guessing the rodent thing is right. If not in the engine intake valley then somewhere the nest stuff got hot. Get out the shop vacuum and look around.

 

[n55luvr]

Many moons ago I had burning plastic smell that turned out to be a plastic grocery bag that I had run over and it instantly melted onto the cat. That little gift kept on giving for quite a while.