My Car Smells Funny

Reader Question
Dear Honest Mechanic, I have 2 questions.

1. A new car gives off no smell from running(being on). The more a car is used,the more miles it has on it, the more car smells come from the RUNNING of the car.

When you turn the ignition on, you can smell it.people buy car air fresheners to cover this smell. I am talking about cars that have NO muffler/exhaust problems.What is coming into the passenger compartment of the car from it running that makes the smell?

2. How long is a rear main seal supposed to last? thank u so much 4 offering to help.

Hey there Deb

Is there an oil leak or a coolant/antifreeze leak? If the heater core is leaking antifreeze there will be a sweet odor inside the vehicle, the windows tend to fog up inside, the radiator will be low on coolant, and the carpet on the passenger floor under the dash will be wet and slick feeling due to the coolant leaking inside the vehicle.

Oil leaks are the same way, except they will leak oil on the outside on the hot engine. Usually produces smoke around the leak when the engine is hot and you will see the oil leak on the ground or on the engine itself.

I have seen a few times a plastic bag that was on the road gets stuck to the hot exhaust system under the vehicle. This plastic burns and produces a smell that can be smelled inside the vehicle. You can have a fast lube place check for oil leaks and if a plastic bag has melted itself to the exhaust system.

On your second question, I have never replaced one on my personal vehicles….so it just depends. I have seen many cars with 200,000 miles and still have the original rear main seal with no problems. I have also seen leaks with 20,000 miles.


Austin Davis

Posted in: Fluid Leaks

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