Maybe this is a ridiculous question but here it goes

Can exhaust fumes get through hairline cracks in a tail light? I read this but I'm not sure I believe it. I'm getting in a random smell mostly when the sunroof is open and intermittently when the windows are open. There are no extra holes in the floorboards. Any suggestions I can look to see where it might be coming through?

Have you looked at the access panel to the fuel tank in the trunk? You have to pull the carpet out. It's right behind the passenger seat.

What is the random smell?

Assuming he means he can smell the exhaust under certain conditions and is trying to figure out how it's getting in.

The best way for me to describe the smell is old. It could be from the cat or the exhaust but it does not smell like gas. What's even more difficult is it's not constant. I do notice it more when I step on the gas.

I had my mechanic look at the access panel months ago and he said it was fine. I bought a new ring and was ready to have it installed.

Hmmm . . . is your tail light cracked bad?

It must have a weather strip behind it. Maybe that's dried out and cracked.

I'll occassionally get a little mouse smell on a hot day. I found a nest in the rear seat back. They've probably gotten under the package tray too.

carguy8888 wrote:

The best way for me to describe the smell is old. It could be from the cat or the exhaust but it does not smell like gas. What's even more difficult is it's not constant. I do notice it more when I step on the gas.

Well, I have guesses.

A smell of "old" sounds more like rotting matter in the air intake. Try first making a gallon or so of a solution made from enzyme based cleaner - disinfectant like Odo Ban or Zep (Home Depot, Sam's Clubs, elsewhere) and pouring it (slowly for the first 1/2 gallon) down the cowl. DIrections are on the label, usually this is like a 5% solution (cup of stuff in a gallon of tap water). Be sure to use an enzyme based cleaner to get at the organic matter that is giving off that smell (bacteria farts).

Next thing - wash the engine compartment.

Do you have oil or coolant pooling on your engine block? Throttle body or intake manifold gasket.

It is hard to describe the smell and I do not notice it with the windows closed. I have poured roughly a gallon of Odo ban diluted down the cow when I thought it was the evaporator.
Pretty sure the engine was cleaned before I got the car and I don't think there's any oil pooling but I will check tomorrow. Believe it or not it's most noticeable when I have the sunroof open but it's not horrible or unbearing, just annoying. I thought it could be the beginning of a cat going bad but I'm just guessing.

carguy8888 wrote:

It is hard to describe the smell and I do not notice it with the windows closed. I have poured roughly a gallon of Odo ban diluted down the cow when I thought it was the evaporator.
Pretty sure the engine was cleaned before I got the car and I don't think there's any oil pooling but I will check tomorrow. Believe it or not it's most noticeable when I have the sunroof open but it's not horrible or unbearing, just annoying. I thought it could be the beginning of a cat going bad but I'm just guessing.

Could be coming from inside the doors. The vapor barrier in the doors breaks down over time.

Could be your carpet needs to be vacuumed thoroughly then shampooed.

I will smell the carpet later but I don't think it has gotten wet.