2012 Civic EX Odd Smell

[Dadbert]

I recently acquired a 2012 Civic EX sedan for my daughter to drive to school. I got it from my father, who maintained it meticulously for 130,000 miles (I have all of his receipts and spreadsheets, and all maintenance has been by the same dealer since new). Recently my daughter has been complaining of an odd smell coming from the engine compartment. I drove it myself, and sure enough, it's an odd smell all right, coming from the engine compartment. I've been around cars most of my life, and this does not smell like oil, coolant, ATF, brakes, wiring, or any other automotive fragrance I've ever encountered. The smell is almost like melted crayons. Sometimes it comes through the HVAC vents, but it's strongest when standing outside beside the engine compartment. I've checked under the hood, and there are no signs of anything leaking, burning, or otherwise amiss (and I HAVE checked for crayons!), and no signs of errant plastic bags snagged on the exhaust underneath. Her friend has an 8th gen Civic, and says she's smelled the same smell coming from her own car, but not as strong.

I searched the forums before posting, and none of the previous threads concerning smells seemed to address this particular odor. Has anyone else ever encountered this, or have any clue what it could be?

 

[daperez13]

Do you live in a high humidity area?

Is the car automatic or manual?

Have you recently performed any fluid changes?

 

[Dadbert]

It's winter here now (though the current temp would suggest otherwise), so humidity has been quite low.

It's an automatic.

Last fluid changes were oil and ATF a couple of months ago, at the dealer; the smell started last week.

I've nosed around under the hood, but can't seem to pinpoint a source.

 

[daperez13]

It's winter here now (though the current temp would suggest otherwise), so humidity has been quite low.

Very little chance it could be mold then but take a look inside the vents and see if they're clean. I believe there's a spray you can use to kill mold.

It's an automatic.

Could be ATF. I know you mention that it's not but ATF does have a distinct odor. Check along the top of the exhaust system to make sure there are no slight leaks that are burning off as they drip.

Last fluid changes were oil and ATF a couple of months ago, at the dealer; the smell started last week.

See above. Did they replace the trans filter or gasket?

I've nosed around under the hood, but can't seem to pinpoint a source.

Try and shine some light around during the night, sometimes, smoke can be seen better if the angle is right (assuming something's burning).

 

[HeX]

I dont know what melted crayons could smell like, but inspect the AC lines and possibly check the AC system pressure as it may have a leak.

 

[XpL0d3r]

Do you have extra sound deadening material lining the trunk, door panels, firewall, etc? Could also be the cause.

I've also heard people report that smell by running over a plastic bag and having it get stuck to the exhaust and start to melt as you mentioned.


This is definitely a strange one.