smelling gas inside car while running heater

[927max]

From last few days I am smelling gas in my car while run the heater for few minutes and when I off the heater slowly the smell subsidies, I also found having some discomfort in my chest. Am I imagining or there could be some problem, I am asking this before I take it to mechanic... please advice

[MTZI30]

Well in the morning the car is going to run much more rich. Do you smell it when you drive or just sitting still? Maybe you could have an exhaust leak? When the heater is on, is it on fresh air or recirculate? If you were breathing in fumes im guessing you'd get sick in your stomach to the point you'd wanna throw up instead of your chest.

[927max]

MTZ,
It is not just morning, in the evening when I drive back home I do smell the same and I smell only when I am driving with heater on. The heater runs on fresh air. I have just recently replaced knock sensor and o2 sensor. I do have exhaust/muffler problem which need to be fixed. I don't feel sick in my stomach but I do feel pain/uncomfortable in the chest.

[MTZI30]

Well it sounds like its only when the car is cold? So it would be running more rich. Maybe sounds like your exhaust leak maybe seaping into the cabin and sucked into the vents? Maybe keep the heater off for a while and just wear a jacket so you dont poisen yourself.

[loystock]

There may be a fuel leak because of a clogged fuel filter (located at firewall, besides brake booster). Check the fuel line between fuel filter and fuel rail for crack/leak.

Make sure the fuel line is empty before disconnecting the fuel filter - FIRE HAZARD. Run the engine and then pull out the fuel pump fuse until the engine dies. Crank a couple of times to ensure line is empty. Replace the filter, re-install the fuse and then start the car and re-check for any fuel fumes.

[927max]

Loystock,
The procedure can be done only by Auto mechanic shop right? I ran the car today with no heater, there was no specific smell but still I felt kind of uncomfortable in my chest, I rolled down the windows for fresh air. I just tried to visit couple of auto mechanic stores during my lunch time and every one is so busy and cannot spare time to look at my car. I will check on saturday.

Is it dangerous to run/drive the car with such uncomfortableness/smell?

[loystock]

Anyone, even with minimal mechanical skills and hand tools should be able to replace the fuel filter, provided he/she safely emptied the fuel line before doing so. It looks like a small can with tubes connected on both sides, adjacent to the brake booster.

Gas fume is considered toxic and may cause you to pass out. It's also a fire hazard. I suggest you have the car diagnosed/repaired ASAP if you cannot perform the suggested repair yourself.

[goody90q45]

......I have just recently replaced knock sensor and o2 sensor......

Did you mechanic have to remove any fuel lines to replace KS? If so maybe one needs re-tightening. Fuel line leaks can go away when the engine warms and the hoses swell so look under the hood with a flashlight when you start the car in the morning and trace the fuel lines looking for leaks.

.....I do have exhaust/muffler problem which need to be fixed. I don't feel sick in my stomach but I do feel pain/uncomfortable in the chest.

The exhaust leak is probably a different problem than the gas you're smelling. Chest pains sound like the beginning of carbon monoxide poisoning to me but I'm just a safety engineer. Think about getting the exhaust leak fixed soon before you're stuck in freeway traffic on a cold morning with the windows closed and pass out.