Sioux-baru Posted May 21, 2014 Share Posted May 21, 2014 Bought a 2000 legacy outback, w/ ovr 300k on it, last fall, ran good for about a month, then the problems started... 1.The MPG started to go down hill. Excess fuel consumption, can smell fuel/ exhaust inside the cabin. unburned fuel? 2.Hold the gas pedal steady and it surges then drops. dont drive it on the interstate as it cant keep the highway speeds due to the surges. I almost want to go out and shoot this car cause i haven't figured it out yet. HELP...... Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted May 21, 2014 Share Posted May 21, 2014 Running like that I would expect there to be a check engine light on. Have you done any maintenance to the car? Plugs? Wires? Filters? Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted May 21, 2014 Share Posted May 21, 2014 check for the cap/o-ring problem on the fuel pump. search for info. check for rusted-thru fuel filler pipe behind the plastic cover, or possibly a leak under the hood. a vacuum gauge might help diagnose surging from a vacuum leAK. Quote Link to comment Share on other sites More sharing options...
unibrook Posted May 22, 2014 Share Posted May 22, 2014 Does it only give these symptoms when the engine is warm? Not when cold? If so, when was last time front O2 sensor was changed out? If more than 40k miles have passed, try replacing that. Quote Link to comment Share on other sites More sharing options...
Sioux-baru Posted May 26, 2014 Author Share Posted May 26, 2014 the kids say the symptoms start after it warms up. the previous owner related that the engine was rebuilt around 250k. due to oil leak / heads. they didnt say when any O2 sensor, plugs or other items were changed out, but I chnged out plugs and filters when i got it. maybe when putitng back together, they messed up the vac lines? I still cant explain the gas smell in the cabin/ through the vents when the car is running. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted May 26, 2014 Share Posted May 26, 2014 Probably needs a front O2 sensor. Check the filler tube in the right rear wheel well for rust. There is a plastic cover over the tube which will need to be removed. The plastic cover traps dirt and moisture and causes the filler to rust and develop pinholes. Also check the fuel hoses under the hood that go to the fuel filter. Quote Link to comment Share on other sites More sharing options...
Battle Wagon Posted May 26, 2014 Share Posted May 26, 2014 Sounds like leaking fuel hose. You're losing pressure somewhere between the pump and the injectors... Pull the cover off the fuel pump and make sure previous owner didn't botch fuel pump install. Even leaky hoses under the hood don't usually cause gas odor in the cabin... Quote Link to comment Share on other sites More sharing options...
mzop Posted November 6, 2014 Share Posted November 6, 2014 Had similar issue, found a bad plug wire, replaced wires because i was running on three cylinders. Still getting evap code p0440 with strange odor in cabin. When i disconnect battery to clear CEL code car runs great for 2 or 3 days, light goes back on and runs bad again, strange smell is constant. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted November 6, 2014 Share Posted November 6, 2014 (edited) Had similar issue, found a bad plug wire, replaced wires because i was running on three cylinders. Still getting evap code p0440 with strange odor in cabin. When i disconnect battery to clear CEL code car runs great for 2 or 3 days, light goes back on and runs bad again, strange smell is constant. Check the actual evap canister for damage/cracking and the hoses going to it. Confirm the plastic check valve in the hose feeding the canister still works (simple check valve like a PCV valve). Inspect your PCV hoses are indeed connected. Inspect all air hoses and vacuum lines are connected and not broken as well. Just because a vacuum line "looks OK" doesn't mean it is, especially in older cars as the rubber hardens in one spot, but will be soft everywhere else. Guess where it'll crack and not be visble? (I just found one on mine that was still attached, but it was split on the hardened "L" bend- a visual only never would have caught it) For $7, buy 6' of vacuum line and replace them as preventative maintenance while looking for the loose hose. I vent my valve cover to atmosphere in my Saab as I haven't welded a bung to a custom turbo intake tube yet, which causes the smell to enter the cabin. It's a rather unique odor that doesn't smell like a normal engine odor i.e. burnt oil, raw gas, coolant, trans fluid, etc. Sorta reminds me of what a smoky tar pit probably smells like. Worth checking out as you might actually have 2 issues at once. I'd go through and do all that, hard reset the battery cable to clear the codes, then drive 50 miles and see if the code trips up again. If you weren't getting the cabin odor, I'd suggest replacing the gas cap (you still can) as that's part of the evap system. When you fill the gas tank up and remove the gas cap, do you hear the "whoosh" sound? Also, when the gas filler nozzle is inserted, does it shut off constantly? Forcing you to pull the nozzle handle again to restart the gas pump? No "whoosh" and the pump constantly stopping are all symptoms of a faulty evap system. The gas cap needs to hold vacuum in the tank, but it could also be the evap canister, or both could be leaking. Simple stuff to sort out. Edited November 6, 2014 by Bushwick Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 7, 2014 Share Posted November 7, 2014 Had similar issue, found a bad plug wire, replaced wires because i was running on three cylinders. Still getting evap code p0440 with strange odor in cabin. When i disconnect battery to clear CEL code car runs great for 2 or 3 days, light goes back on and runs bad again, strange smell is constant. Filler tube is probably rusted out. Very common, and allows liquid fuel to escape the tank which causes a substantial amount of fuel vapor to drift under the car and come up into the cabin. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted November 8, 2014 Share Posted November 8, 2014 (edited) Had similar issue, found a bad plug wire, replaced wires because i was running on three cylinders. Still getting evap code p0440 with strange odor in cabin. When i disconnect battery to clear CEL code car runs great for 2 or 3 days, light goes back on and runs bad again, strange smell is constant. Filler tube is probably rusted out. Very common, and allows liquid fuel to escape the tank which causes a substantial amount of fuel vapor to drift under the car and come up into the cabin. Sounds more like the engine isn't purging the fumes the way it should. A rotten filler neck would be constant and wreak of gas and is distinguishable from emissions fumes. His is happening after x-amount of time after a reset, which seems to point to the actual evap canister, it's valve, a broken hose, etc. i.e. something that gets activated after certain engine parameters are reached. Edited November 8, 2014 by Bushwick Quote Link to comment Share on other sites More sharing options...
mzop Posted November 14, 2014 Share Posted November 14, 2014 evap Canister Seems to be ok, I'll check the house with in line valve, pcv valve hose is on tight. I'll probably replace all the vacuum hose i can to eliminate any issues. I do have a new gas cap, not oem, no whoosh sound, no shut off problems when refueling. Gas filter tube is rusted and probably needs replacement. I definitely think there's something with the evap canister or in line valve. When you're outside the car you can smell/taste exhaust. I also have brake booster issue,could this tie into evap problem, tested booster, not airtight. Quote Link to comment Share on other sites More sharing options...
mzop Posted November 14, 2014 Share Posted November 14, 2014 Bushwick, think your on to something with the parameters being reached and cel coming on. After i disconnect battery and clear cel car runs great. I think computer figures out problem and sets off code. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted November 14, 2014 Share Posted November 14, 2014 (edited) Your gas tank should be under vacuum. The "whoosh" you should hear at the pump is air entering the gas tank. The immediate fuel vapors you smell being released every time the gas cap is removed, is what the evap system is supposed to be pulling into the charcoal canister, then under certain circumstances, pulling that into the combustion chamber so it's gets burnt off rather than being allowed to escape into the atmosphere. If the vapor fume concentration gets REALLY high in the tank, it'll pour out the gas filler opening. This is what shuts the pump off, as the nozzles have a detection device to detect the vapors being forced out, and is how automatic pumps work. On really hot days, when warnings go out, this is the vapors they are talking about. Sounds like your evap system isn't holding vacuum. When you reset your codes, the ECM is starting from a day 1 scenario (I believe) where it should be "thinking" there is no vacuum in the tank, so it goes through whatever parameters Subaru has set up on how long it should run before trying to burn off the stored fumes in the canister. Once it's ready to do so, I believe (in your situation) it's not detecting the correct vacuum or vapor presence (unsure exactly what yours is checking), and it's throwing the code. You definitely sound as though you have an air leak somewhere. Read this for a quick understanding on evap systems and their functions: http://www.greatautohelp.com/operation/EVAP-System-Codes-Tests.html A brake booster canister is essentially a large vacuum can with a check valve feeding into it, with a diaphragm inside that's manipulated when you press you brake pedal. Not sure how you determined it's not "working" correctly, but the canister itself should be air tight. The rubber grommet the check valve feeds into shouldn't be dry rotted (or missing). And the actual hose feeding the check valve shouldn't be leaking either. Can use sprays to detect leaks on vacuum hoses. If the engine surges, you found the leak. Test leaks on a cool engine to prevent flash fires and don't use heavy oil products that can sit or soak and cause fires. Also, moving the vacuum hoses/lines while spraying is better as you might have a small crack or leak that's not evident if the hose is in it's natural, hardened position as it can seal minor leaks. Any hoses after 10 years or so typically need replaced anyways, so dropping $10 on new vacuum lines is smarter than ignoring them as vacuum leaks can lean out the AF mixture which isn't good. They can also let minute amounts of dirt enter the engine. Evap issues can cause all sort of drivability problems, but the car can at least still run. If you have emissions testing in your state, it'll most likely fail the inspection. I was surprised my check valve was seized up as it didn't throw ANY codes and never would have known had it not been physically checked. But at least the idle is more stable in gear at a stop light and isn't surging or dropping below 500 rpm now. Also, check the rubber hose that runs just below the gas filler tube to see if it's ripped (look under the car, you should see it running off the actual filler tube). Edited November 14, 2014 by Bushwick Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted November 15, 2014 Share Posted November 15, 2014 Filler neck. There's an exhaust pipe that runs under the tank. When the car has been running a while the fuel in the tank warms up befause of heat from the exhaust system. The heat causes the fuel to evaporate, and the fumes to somewhere. If the tank is sealed vapors would normally be directed into the evap canister. If there is ANY small leak in the hoses or anywhere else, fuel vapor will be pushed out of there rather than going through the canister. The filler neck is the prime place for fuel vapors to escape. Yank the plastic cover off the filler tube and you'll likely find that it looks like Swiss cheese. 2 Quote Link to comment Share on other sites More sharing options...
Bushwick Posted November 15, 2014 Share Posted November 15, 2014 One other thing with the brake booster grommet that seals the check valve. Be careful with the grommet if you try removing it for a thorough inspection and/or replace. It's possible the new/old one can get pushed into the canister when trying to reseat against the lip. If that happens, it'll be a PITA to get it back out. A fish hook bonded to a magnetic wand might be enough to lift it to the hole where needle nose pliers could grab. Also, if the grommet is rotted on the inside, it'll shed it's debris in the canister which can be problematic as well. If you replace the main vacuum hose going to the booster from the engine, make SURE it can handle several BAR as a flimsy hose won't cut it. Quote Link to comment Share on other sites More sharing options...
mzop Posted December 6, 2014 Share Posted December 6, 2014 Fixed brake issue, figured out check valve in booster vacuum hose bad, $30 at dealer and brakes are good. Will get back to evap now that safety issue fixed. Quote Link to comment Share on other sites More sharing options...
Bushwick Posted December 6, 2014 Share Posted December 6, 2014 Sorry for giving wrong info on the grommet. Never looked closely at mine, and it actually has a metal tube welded on, as opposed to say Ford stuff that had a rubber grommet over the hole in the canister, which the check valve resides in. Glad to hear your brakes are at least working with a new check valve though. $30 is pretty steep, but it's worth it to have a solid pedal. Quote Link to comment Share on other sites More sharing options...
mikaleda Posted December 7, 2014 Share Posted December 7, 2014 The purge cylinoid will only open and allow the fumes to be sucked out of the tank when the car is travailing at a steady even pace for an extended period of time like driving down the highway. Now as for your problem, I think fairtax is right, the fuel filler neck IS a common issue in these cars and is not hard to pull the cover over it and inspect it, that would be the next step in my opinion Quote Link to comment Share on other sites More sharing options...
mzop Posted December 7, 2014 Share Posted December 7, 2014 Inspected filler neck, huge hole at top of it, could fit a couple fingers in it. Temporarily patched with emergency tape and duct tape till part new part arrives. Actually runs better already. Quote Link to comment Share on other sites More sharing options...
mzop Posted December 12, 2014 Share Posted December 12, 2014 Well, i replaced filler neck, found one in great condition at junk yard for $15, going to clean it up and put rubberized spray on it. Then I'll put plastic cover on. Car runs much better, on 5th day without check engine light on. Still getting an slight exhaust smell in cabin. Wondering if i have an exhaust leak. Thank you for all your advice on this guys. Quote Link to comment Share on other sites More sharing options...
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