Odd Exhaust Smell, My Tacoma Doesnt Do This!

So my moms car has this odd smell from her exhaust it smells more like burned/burning oil rather than what a typical exhaust smells like. It is not smoking or anything, just smells terrible. The exhaust on my truck or any of our other toyota's never smell like that. Her car is the only car we have that isnt toyota.

she has an 06 E350 mercedes benz. with about 56K miles.

 

is it a diesel?

 

my first thought as well

 

Sounds like the catalictic converter is going bad.

 

could be burning small amounts of radiator coolant? More symptoms needed.

 

well the weird thing is, it drives fine. Im not getting any errors on the dash, still drives and sounds smooth. Everything on the car is okay except that smell

and no its not a diesel LOL. i definitely know how a diesel would smell like.

 

is it a foul smell? Sweet smelling? any of the fluids super low? Does it do anything at all different?

 

lost any power? did she bottom it out really hard on a curb or something and hit the cat on the ground? did she change from her regular gas?

 

maybe its just running a little rich for some reason.. air sensors or things like that bad

 

After the recent threads about crackheads on here I would check the trunk first.....

 

rotten egg smell?

 

X2

 

you sure youre not passing gas while standin next to it?

 

DOH!

 

how can you determine cat when guy hasnt said anything about it?

it could be a host of issues..!

 

LOL as far as i know, i wasnt passing any gas

i wouldnt say its a rotten egg smell, it definitely smells like motor oil, but just burned or burnt.

And nope i dont think we've lost any power and i doubt shes bottomed it out anywhere. Like i said, it still drives fine and like new. Shes a little asian lady who drives really slow and careful hahah. She thinks i drive wreckless

As for the fluids everything checks out. and i dont know about the sensors, if there was something wrong with the sensors wouldn't that throw a check engine warning at us?

 

Is the smell coming from the rear exhaust, or from under the hood? If it's from the rear exhaust then it's either cat's dying, running to rich/lean. If it's from under the hood... something is probably leaking onto the exhaust (power steering fluid, brake fluid, coolent, oil, something). Also, it's possible the header is seperated slightly or there is an exhaust leak somewhere.. where you're getting unfiltered exhaust straight from the head coming out. If it sounds a bit louder than normal try to isolate where.

 

yeah its definitely the rear.

How can i know for sure the cat is dying or its running to rich or lean? If its running rich/lean shouldnt i be able to tell by how the engine sounds and runs?

 

Yup and if you're running rich you should also see a decrease in fuel mileage. Is there a thick layer of soot around the exhaust tip?

 

Sulfur smell=bad cat. Burned oil smell= something on exhaust melting, engine burning oil... Could be anything. Further inspection is needed.