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Hot Wax Smell from under the hood

Intermittently after I’ve been driving on freeway, when I stop there is a strong smell of “hot candle wax.” That’s the best I can describe it. It doesn’t occur when driving around town at slow speeds. Only after some time on the road driving 55+. It can be smelled coming from under the hood outside but lately the odor has been coming inside my vehicle as well.

Have you opened the hood to see if you can determine where, exactly, the smell is coming from?

I personally have not because the hood latch is broken and it takes using a screw driver and some muscle to make it latch once it’s been opened (I am 72 years old, so it’s not easy for me. And I’m … eeek … a woman) Buuut, I did ask a friend to do so and he couldn’t tell. The smell dissipates rather quickly once the car is idling or off.

I had a customer make the same complaint only she insisted that it was the radio that was the source of the smell. Well we had a pretty loose policy on radio exchanges (this was with GM) so I put a radio in it, in facr I put two in it. When the customer came back the third time still insisting that the radio was the source of the smell I decided to do my own diagnosis. Well it turns out there was a plastic grocery bag stuck to the catalytic converter. You might want to give the underside of the car a look and see if something is stuck to the exhaust.

Way ahead of you there. I had done some googling and found that suggestion, and checked. No plastic bag. Besides, this is a carry over from last spring, so if it had been something plastic it’d no doubt be “burned off” by now. In fact, because the smell was so intermittent, I actually at one point decided that maybe WAS what it was … but then it started happening again. I read somewhere that leaking antifreeze hitting heater core (does that make sense) could cause a sweet smell, and someone asked me if it was a sweet smell. Is the smell of burning plastic/wax sweet to some people? I really am at a loss. I took it to a local fix-up shop, and he test drove it and everything, and it wouldn’t act up for him. Sigh.

  1. I’d take a closer look at the plastic bag theory. I had that smell for months on my Escort. Depending on where it sticks, say on the undercariage rather than on the exhaust itself, it could take a while to cook off. This could also explain why it only occurs under heavy load (on the freeway) and goes away at low speeds and idleing where the exhaust is not as hot. The other watchout here is how could it be getting in the car. If you have an older car could there be holes in the floorboards?
  2. If you suspect the coolant, is your coolant level dropping over time? Any drips on the drive?

I will do that … it’s worth a try. I’ll get a grandson to crawl under and see what he sees. A car that old could have all sorts of holes, I suppose; not sure how’d I know that unless I took it to a shop and asked them to hoist it up and tell me. I’ve started to think the muffler sounds loud which makes me suspect a muffler leak, so maybe that is how it could coome in?

I realize I’ve not thanked a single person for attempting to help me tonight … thanks to everyone for taking the time. I really do appreciate it.