heater on = gasoline smell!!! help!

[thisdsm]

Help me out guys. Everytime I turn on my heater there is a strong smell of gasoline. This only happens when the car is not in motion but once the car is in motion the smell disappears. Thanks!

 

[myblack98gst]

sounds alot like your heater core may have a leak in it.. I am not 100% sure where it is located, but it is behind the dash. After a day of driving around with the heater on, check the carpet under the dash to see if it is wet.

 

[TurboJunky]

sounds like either that or possibly leaky fuel lines. check them all.

 

[GSntncT]

how about a leaky injector seal? I had the same thing happen a year ago, and that's whatit was for me.

 

[ktmryan53]

to bring this thread back from the dead....
i am currently experiencing the same issue. its not a fuel problem as if you stand in front of the car with it running you do not get the overwhelming smell of gas like you do inside the car. i am doubtful its an injector seal since once again you dont smell that standing in front of the car with the hood open. how can it be the heater core? i didnt notice any moisture near the feet sections of the carpet. the heater core(whole system for that matter) should not be linked together like how the coolant smell would be a real possability but this is most definately a gas smell. i am stumped on this one. as the other guy said it is worsened X10 when you stop.

 

[toybreaker]

I would take a raw fuel smell very seriously!

If only you smell it with the heater on, it is probably coming from the engine compartment. Usually it will be obvious, like a leaking injector o-ring, or maybe a leaking crush washer at the fuel filter.

I would recommend that you visually follow the path that the fuel takes thru the engine compartment. Start at the fuel filter, follow the hose up to the fuel rail, check the injectors where they seat into the rail and manifold, check the fuel pressure regulator, and it's fittings, and the return hose to the firewall. I would also pull the vacum line off the fuel pressure regulator and check it for raw fuel. Many times the system will only leak intermitently. If this is the case look carefully for fuel stains around the injectors, and all the connections. It will leave a clean spot/trail if there's any oil/dirt, with a fresh leak, short term, and a varnishy looking residue over time.

Then, there's the charcoal canister. It accepts the fuel vapors from the tank. The fuel in the tank will expand and contact with temperature, and these vapors are sent to the carbon canister, where they are absorbed by the activated charcoal/carbon granules in the carbon canister. When the ecu turns on the purge solenoid, and vacum is applied to the purge valve, vapors will flow from the canister thru a hose to the intake ducting between the airflow meter and the turbo, (or throttle body on n/a cars), where the very slight suction will pull the vapors into the intake airstream.

If the canister gets damaged, you may smell fuel at odd times, while driving, while sitting still, or just walking by the car on a warm day...any time the tank is venting vapors.

If the purge valve gets broken/disconnected from the hose to the intake duct, you'll smell the vapors with the car moving. Because the ecu controls the purge solenoid, and throttle position controls the vacum to the purge valve, you will not smell the vapors sitting still, (because the ecu will not authorise purge solenoid at idle, and there will not be vacum present at the purge valve, because the throttle is closed.) So if you only smell it moving, I'd give the purge/evap system and hose to the ducting a thorough visual examination.

On occaision, the canister can get saturated with vapors, or maybe swallow some liquid, tease: overfilling your car at an angle because you found cheap gas , not that I would know ) and it will smell like raw fuel. The charcoal canister is vented to the atmosphere thru a fiberous filter located at the bottom of the canister. If the filter media gets saturated as well, you may smell the vapors for a day or two.

Hard driving on a full tank can also slosh fuel around enough for the evap system to swallow a little liquid, which can give a fuel smell for a short time.

Another common problem is the top of the fuel tank on all wheel drive cars. Dirt and water will collect and rust the top of the tank, and it's fittings. This is another situation where you may only smell fuel with the car moving. As the car moves thru the air, a slight low pressure area forms behind the car. It will pull any vapors off the top of the tank, and then pull them along with you in your slipstream. You may notice the smell as you're motoring along. If you have your windows down, you'll notice it when you come up to a stop, that's for sure. There's an access panel in the trunk, under the carpet, which allows for a reasonabally quick visual inspection. Check the lines, fittings and fuel pump/sender housing gasket for any seepage/staining.

^As an aside, this is almost exactly the opposite symptom as the original poster. With the windows up and the heater fan on, the fan will create a very slight positive pressure that will actually force any vapors from the rear of the car back out.

Please, let us know what you find!!! Fuel leaks scare me, and I'd like to know that every single one gets tracked down and dealt with on every car that every one owns.

Fuel fires suck!!!

 

[herblove]

great reply toybreaker.. I'm getting the gas smell also. I know that my fuel tank is missing 2 of the nuts that go on the top of the tank where the pump goes.. Will silcone that. I also run no pcv vavle. I think that gives you a vapor smell.

 

[ktmryan53]

excellent post. well i do not have any emmissions piece-ie the canister so that is ruled out right away. it does only happen when the windows are up so that pretty much rules out the leaking tank- at least i dont notice it with the windows down. the problem came very randomly and sudden. it has since stayed consistent for at least 2 weeks. i am tracing the fuel lines now.... i didnt replace the filter or anything like that but will check it. my gas gauge seems to also be working properly so im doubting the return line issue but will also check.

 

[ktmryan53]

ok so i traced all the fuel stuff. i smelled a little gas from the retrun line on the fuel rail but it SURE was not as much as it smells inside the car. i did not see any leaks or any areas that seem to be of immidiate concern.

 

[toybreaker]

If you can smell it moving, or stopped, but only with the heater/a/c on, (and the fresh/recirculate mode set to fresh) it's most likely a problem in the engine compartment.

Any fuel fumes in the engine compartment can be drawn into the car by the climate control system. The fresh air inlet for the heater/ac/ventilation system is on the top of the cowl, just in front of the windshield. When the vehicle is moving, high pressure at the base of the windshield will provide a (slight) positive flow thru the ventilation system. (even with the fan off)

So, maybe we can narrow the search down some.

You said the carbon canister is missing in action?

That creates an interesting question. How is the tank vented?

If the lines were simply left open, I would bet 1 us dollar that you're smelling the tank venting as the fuel gets moved around. Fuel is hot lapped from the tank up to the fuel rail and back, (as the pump supplies more than the engine can use, and the fuel pressure regulator bypasses the excess back to the tank.) As it travels up to the engine compartment and back, it will pick up heat and expand. Those vapors used to go to the carbon canister to be stored and/or sent on to the intake airstream to be ingested by the motor and burned. Without a connection between the various components that authorise and supply the vacum to control the purge valve, and the hose from the canister to the inlet ducting, I'm thinking there's a possibility the tank vapors are getting discarged into the engine compartment, and you're smelling them when they are picked up by the climate control system.

An interesting anomoly of fuel vapors is that they are heavier than air and will sink to the ground in still air. This means you may not smell the fumes very strongly, with the car stopped when you open the hood, as they're lurking closer to the ground.

I would still investigate the fuel odor at the fuel rail/fpr/return line. Please look very carefully at the base of the injectors for stains/discoloration, and then triple check the fpr. They can spring a leak at the flange. You can pull the vacum reference line off, (small hose,it goes over to the intake manifold), it should be dry inside.

Is there any way you could post a picture of the carbon canister mounting area, with any lines/hoses that are visible. It would make things easier to understand, (and also ensure I'm not sending you down a dirt road.)

Thanks!

 

[ktmryan53]

well it looks like i found the problem. i have an exhaust leak from the bottom of the #1port. i used an oem gasket when i put the 6 bolt in. anyone know of thicker gaskets? i havent fixed it yet but it makes sense and im hoping it is this simple.

 

[92eagleTSI]

So your saying you have raw gas coming out of the #1 exhaust port?

 

[ktmryan53]

essentially yes, well from all 4 cylinders but #1 is the one i feel leaking. im not saying im spraying raw gas but i had some issues with the firing happening at the improper time(base timing issue) and basically igniting in the manifold. the car is still running extremely rich but it is progressively getting better with my tuning abilities increasing and getting dsmlink should help a ton.