Smells Coming From Engine Area While Driving

[clamum]

So sometimes when I'm driving I'll smell like a "burnt" smell for a few moments, from the engine area. When it first happened, I thought maybe it was another vehicle by mine but nope, it's definitely my car. The smell has been like a burnt oil or oil smell, to some other burnt smell (almost like burnt plastic? Or chemical? I dunno man).

Has anyone ever experienced something like this before? My car does "burn" or go through oil at a faster rate than normal, I'd say, because by about 5000 miles I need to get an oil change because the oil level is super low (I start checking it during every fuel up stop when it gets to be around that time). I get synthetic oil and the sticker I get is for like 7500 miles, but there's no way I could last that long. So maybe the oil smell I'm smelling is some drops of oil hitting a hot surface, but that doesn't explain the other smells (which are different than an oil smell).

it's been making me nervous lately, but my engine temperature is always fine (halfway between C and H, like it always is) and no lights have ever came on, and honestly it's been happening for quite a while (over a year) but I haven't seen any ill effects besides the faster oil usage. It sucks because there's no specific time I can say it happens, so I can't just tell a mechanic to take it for a ride; it has happened when I'm accelerating to get on the freeway and while coasting slowly to a stop light. I could even go on the drive to work (mostly freeway; 11.5 miles) and never have it happen.

 

[lxskllr]

Is the smell kind of nasty, as opposed to smelling simply oily? Could be gear oil. Burning clutch, rear leaking...

 

[Captante]

Its most likely some kind of oil hitting the exhaust manifold in small amounts when the engine is cold/warming up. Inspect carefully for nasty buildup on and under the engine which might indicate a leak. If you park in a secured area put a light color drop-cloth or sheet under the motor area for a week or so.

Its also possible a piece of some plastic road debris is wedged between the exhaust and floorboard and slowly burning and stinking... had it happen.

 

[clamum]

Is the smell kind of nasty, as opposed to smelling simply oily? Could be gear oil. Burning clutch, rear leaking...

I don't really know how to describe it. To me, there's a pretty distinct burning oil scent that'll happen, and there's also a different burning scent that occurs at times too. It's different than the oil smell (I'm pretty confident that first smell is burnt oil) but I'm afraid I just don't know what it is or how to describe it. I'll try and pay more attention next time. WE NEED TO BE ABLE TO SHARE SCENTS OVER THE INTERNET

Its most likely some kind of oil hitting the exhaust manifold in small amounts when the engine is cold/warming up. Inspect carefully for nasty buildup on and under the engine which might indicate a leak. If you park in a secured area put a light color drop-cloth or sheet under the motor area for a week or so.

Its also possible a piece of some plastic road debris is wedged between the exhaust and floorboard and slowly burning and stinking... had it happen.

Thanks for the suggestions. I'm going to call the garage I bring my car in for oil changes and get it in so they can look at it. Like I said, it's annoying because that smell doesn't happen a lot or all the time so there's a good chance if they take it for a test ride they won't smell anything (and probably think I'm going crazy). Hopefully if they look over the car though they might spot something.

I'm just hoping the fricking thing doesn't die on me while I'm on the freeway or something. Like I said, I've noticed it having those smells for quite a long time (over year at least, probably a couple) but I just put it down to it slowly dripping oil somewhere hot, cause I know it seems to go through oil faster than it should. But unless I'm going nuts, it's causing these smells more and more often now so that's why I'm getting nervous. Gotta get that mofo in and hopefully they find something.

 

[Paperdoc]

Considering that you already know the engine loses oil in some manner faster than expected, it is likely caused by one or more oil leaks. (The other option is burning oil in the cylinders caused by worn rings or valve seals, but that's less likely.) I do not know whether synthetic oil being scorched on a hot exhaust manifold smells the same as or different from the smell of standard petroleum-based oil. IF it is oil landing on the exhaust manifold, then probably it's from higher up, which might point to valve cover gasket. Your mechanic may have better luck finding it, because he / she has experience spotting these things.

Another source of odd burning smells, though not the same smell, is a radiator antifreeze / coolant leak that sprays onto a hot surface. Has the level in your rad surge tank been falling? Is the rad still full when you remove its pressure cap ONLY WHEN THE ENGINE IS COLD?

 

[C1]

There are complaints regarding excessive oil consumption with various new model vehicles. (Do a google search to find out.) The manufacturers claim though that it is now normal. I suspect that it is in part because of the move to very low oil viscosities with 0-20w being now typical.


Inspect your engine for head gasket leak. Use a strong flashlight at night or in darkened garage to determine if oil is seeping from the engine's head and running down the side of the engine block.

Also, coolant leaks are classic for being intermittent. Such leaks happen sometimes only when the system pressure peaks such as after running hard on the freeway, then parking & turning off the engine (results in very short term coolant over pressure due to hot block heat infusion into non-circulating coolant). The smell is described as being "sweet."

Also, check for coolant leaks around timing chain cover as well as water pump (particularly the water pump vent hole).

Inspect serpentine belt for oil or coolant contamination.