Exhaust/Gas in Cabin
#1
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Exhaust/Gas in Cabin
This is my first post on this forum. I have a 1999 SC 300 with about 127K miles (all stock). Done a bunch of maintenance in the last month such as brakes, all fluids have been changed, valve cover gasket replaced etc. I have a weird smell in the cabin when the blower is on. Initially I thought it was the oil that was leaking from the valve cover gasket (which is why I got it replaced) but it's still there. The smell is virtually non existent but I sometimes get a headache when I'm driving.
I thought it was Carbonmonoxide coming into the cabin from the exhaust and got the entire exhaust checked out my a muffler shop and there were no leaks. There seems to be some posts with leaks around the headers and I've asked the shop to specifically check for that - but everything is fine.
Engine is strong no oil leaks. Does anyone have ideas on what it may be? The smell is really very faint to pick up but when I come home and take a shirt off, it kinda smells like oil. I guess my nostrils get immune to the smell over time which is why I think it's nonexistent. I've also tried a CO detector and it came up negative.
Any ideas would be appreciated.
I thought it was Carbonmonoxide coming into the cabin from the exhaust and got the entire exhaust checked out my a muffler shop and there were no leaks. There seems to be some posts with leaks around the headers and I've asked the shop to specifically check for that - but everything is fine.
Engine is strong no oil leaks. Does anyone have ideas on what it may be? The smell is really very faint to pick up but when I come home and take a shirt off, it kinda smells like oil. I guess my nostrils get immune to the smell over time which is why I think it's nonexistent. I've also tried a CO detector and it came up negative.
Any ideas would be appreciated.
#4
Instructor
iTrader: (6)
most likely has something to do with your EVAP system, Usually when you smell gass in the cabin its from a bad purge valve but it could be something as small as a vacuum line as well or even a backed up charcoal canister.
Start by having someone inspect the evap emissions system
Start by having someone inspect the evap emissions system
#6
Lexus Champion
iTrader: (10)
I would check the charcoal canister, especially if it started to happen on a warm/hot day.
sometimes there will be too much gas vapor buildup in the charcoal canister when the car is sitting, and it will vent off in your engine bay more or less to protect the canister from too much pressure.
this happens mostly on hot days or if the car is sitting in the sun because the heat will build up alot of gas vapors in your tank and hence your canister. The ecu only purges the canister under cruise conditions and some other part throttle conditions, which means if you start your car on a hot day and drive short distances, you wont purge your canister enough, eventually you get too much buildup, and presto you are smelling your wasted gas vapors.
the other scenario where this happens alot is if you accidentally overfill your gas tank, you can fill the canister with some fuel, which will more or less ruin it in the longrun and cause similar symptoms if the gas can't work its way out of the canister.
This leads to one of my few pet peves with the SC. on some cool temp settings the default is pulling in fresh air which will suck in that smell from your bay. If you press the button to get the a/c to recirculate to avoid smelling that smell, turn off the car, and turn it on again, the a/c will default back to taking in fresh air and if you don't remember your car smells like gas again.
Hopefully a Lexus engineer is reading this when I say recirculate I mean recirculate till I press the button again!! not remember all my settings except for that one on the next start =(
sometimes there will be too much gas vapor buildup in the charcoal canister when the car is sitting, and it will vent off in your engine bay more or less to protect the canister from too much pressure.
this happens mostly on hot days or if the car is sitting in the sun because the heat will build up alot of gas vapors in your tank and hence your canister. The ecu only purges the canister under cruise conditions and some other part throttle conditions, which means if you start your car on a hot day and drive short distances, you wont purge your canister enough, eventually you get too much buildup, and presto you are smelling your wasted gas vapors.
the other scenario where this happens alot is if you accidentally overfill your gas tank, you can fill the canister with some fuel, which will more or less ruin it in the longrun and cause similar symptoms if the gas can't work its way out of the canister.
This leads to one of my few pet peves with the SC. on some cool temp settings the default is pulling in fresh air which will suck in that smell from your bay. If you press the button to get the a/c to recirculate to avoid smelling that smell, turn off the car, and turn it on again, the a/c will default back to taking in fresh air and if you don't remember your car smells like gas again.
Hopefully a Lexus engineer is reading this when I say recirculate I mean recirculate till I press the button again!! not remember all my settings except for that one on the next start =(
Last edited by Ali SC3; 06-14-12 at 01:42 PM.
#7
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Thanks a lot for the tips. I will try them. One thing I tried last week was replace the in-cabin filter. Man - there was so much junk in there it was amazing to see. Couldn't believe I was breathing air coming through that filter...
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