I went to change the air filter on my 07 F150 the other day and got a whiff of gas when I did so. This is the first vehicle I've had that has a panel filter that sits right above the throttle body. I drive the truck a few times a week and all trips are 90 mile highway trips. It does sit for days at a time though. It does have a custom tuned PCM. It doesn't smell like it's running too rich but I have no a/f gauge to tell. Is this normal or should I be looking for something?
Gas smell on air filter
- Thread starter msmoke00
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Are you getting a lot of soot in the exhaust pipe? That would indicate a rich condition.
Also, pull the plugs -- another way to see if it's running rich.
Also, pull the plugs -- another way to see if it's running rich.
Sounds serious as no engine except an old classic race one should smell of petrol ever. Fuel line, pump or injector rail leak?
Take a sniff whilst not smoking, but be careful of eye injuries near the injectors (Wear glasses if getting close to the pump or injectors with the engine running).
Take a sniff whilst not smoking, but be careful of eye injuries near the injectors (Wear glasses if getting close to the pump or injectors with the engine running).
No soot in the exhaust. Clean and no black smoke ever. Changed the plugs 5k miles ago and things looked very good. Didn't even break any on these trick 3V motors. No leaks anywhere. The only time I smell any is when I took out the air filter. The filter is a panel that sits square above the intake manifold. Does a little fuel normally sit after shutdown in the ports? That's the only way the fuel smell could get there that I could think.
Two thoughts to consider. I don't know if these are realistic as I can't smell gasoline all that easily. I worked at a gas station for a few years back in the day and got used to the smell.
Had you most recently run the engine for a very short time? Fuel vapor could possibly still have been in the tube from the VMV when you shut the engine off and spread into the intake. It's a miniscule amount, but some people are very sensitive to the smell.
Also, when you shut the engine off there should be a tiny amount of of fuel that's sprayed out of an injector but hasn't passed by the intake valves of one or two cylinders, again this is not nearly enough that I'd smell it, but maybe you could.
Much more likely to give you a significant fuel smell from the air cleaner would be a leaky injector. To check that you'd need either a pressure gauge or pull the rail. If you have a leaker, to identify it would take a compression tester or a boroscope or again, pull the rail or you might be ably to identify it by looking at the plugs.
If you have a leaky injector the easy answer its to replace it. The less easy answer is cleaning. There should be lots of info about injector cleaning on BITOG. Also, maybe you'll get lucky and Trav will chime in on this one.
Had you most recently run the engine for a very short time? Fuel vapor could possibly still have been in the tube from the VMV when you shut the engine off and spread into the intake. It's a miniscule amount, but some people are very sensitive to the smell.
Also, when you shut the engine off there should be a tiny amount of of fuel that's sprayed out of an injector but hasn't passed by the intake valves of one or two cylinders, again this is not nearly enough that I'd smell it, but maybe you could.
Much more likely to give you a significant fuel smell from the air cleaner would be a leaky injector. To check that you'd need either a pressure gauge or pull the rail. If you have a leaker, to identify it would take a compression tester or a boroscope or again, pull the rail or you might be ably to identify it by looking at the plugs.
If you have a leaky injector the easy answer its to replace it. The less easy answer is cleaning. There should be lots of info about injector cleaning on BITOG. Also, maybe you'll get lucky and Trav will chime in on this one.
Forgot to add the truck only has about 50k miles on it. It's a consistent smell, even after a long trip. I don't have a gauge, so how do I identify a leaking injector with the fuel rail? I've run a couple bottles of Techron since I've had it so the injectors should be clean.
If I'm misunderstanding this and the fuel smell showed up when you walked over to the truck (not when you took the air filter out) that's another story. Normally, with the engine off, there is a path that allows fuel vapors to flow through the the charcoal canister to outside air. The charcoal is supposed to absorb the fuel vapors and store them to be burned later but it has a limited capacity so after sitting for several days it can become full, so to speak, and allow fuel vapors out into the atmosphere. If the truck is stored indoors, you might well be able to smell it as you approach the truck.
This is not a harmful thing unless you park your truck in a garage and leave such things like a space heater or fan or other possible ignition source operating unattended at ground level. If you do, stop doing that and move all possible ignition sourced up high.
This is not a harmful thing unless you park your truck in a garage and leave such things like a space heater or fan or other possible ignition source operating unattended at ground level. If you do, stop doing that and move all possible ignition sourced up high.
not trying to second guess your spark plug job, but did you snug the plugs down properly?
I did the torque spec on my ecotec 2.2 and must have not done it right because there was a fuel smell in the engine bay. Tightened by feel and all was good. Just a thought.
I did the torque spec on my ecotec 2.2 and must have not done it right because there was a fuel smell in the engine bay. Tightened by feel and all was good. Just a thought.
Originally Posted By: msmoke00
Forgot to add the truck only has about 50k miles on it. It's a consistent smell, even after a long trip. I don't have a gauge, so how do I identify a leaking injector with the fuel rail? I've run a couple bottles of Techron since I've had it so the injectors should be clean.
Do this with the engine cold. Sometimes an injector will leak only when engine heat warms it up but that's not all too common and we don't want any vehicle fires.
With the fuel rail out, blow air on the nozzle end of all the injectors until they appear completely dry. You don't need compressed air or even a fan, just blow on them. Cycle the ignition key on and off two or three times slowly, then watch the injectors very carefully for 20 minutes or so. If any of them develop dampness at the nozzle end, there you go.
Forgot to add the truck only has about 50k miles on it. It's a consistent smell, even after a long trip. I don't have a gauge, so how do I identify a leaking injector with the fuel rail? I've run a couple bottles of Techron since I've had it so the injectors should be clean.
Do this with the engine cold. Sometimes an injector will leak only when engine heat warms it up but that's not all too common and we don't want any vehicle fires.
With the fuel rail out, blow air on the nozzle end of all the injectors until they appear completely dry. You don't need compressed air or even a fan, just blow on them. Cycle the ignition key on and off two or three times slowly, then watch the injectors very carefully for 20 minutes or so. If any of them develop dampness at the nozzle end, there you go.
yonyon: This is only with the truck off. I took the air filter out and the filter itself smells of gas on the bottom side. It is stored in doors and sits for four or five days at a time. It's a weekend ride.
Mailbu: I torqued everything to spec (24 ft/lbs) and was there before and after the plug job so nothing to do with that.
Mailbu: I torqued everything to spec (24 ft/lbs) and was there before and after the plug job so nothing to do with that.
I expect it'll turn out to be a leaky injector. Go ahead and try as I've said unless someone comes up with a better idea before you get to it. Also, I should have mentioned that when you turn the key on with the rail/injectors out there's a possibility one of the injectors could just maybe pop off the rail and spray gasoline all over the place. If that happens, turn the key off and open the garage door until everything is dry.
Don't forget to lube your injector o-rings before putting them back in their holes.
Don't forget to lube your injector o-rings before putting them back in their holes.
Originally Posted By: yonyon
I expect it'll turn out to be a leaky injector. Go ahead and try as I've said unless someone comes up with a better idea before you get to it. Also, I should have mentioned that when you turn the key on with the rail/injectors out there's a possibility one of the injectors could just maybe pop off the rail and spray gasoline all over the place. If that happens, turn the key off and open the garage door until everything is dry.
Don't forget to lube your injector o-rings before putting them back in their holes.
+1 lol hopefully your fuel rail has some sort of clip that keeps the injector in place. vasoline works well for lubing the rubber prior to install
I expect it'll turn out to be a leaky injector. Go ahead and try as I've said unless someone comes up with a better idea before you get to it. Also, I should have mentioned that when you turn the key on with the rail/injectors out there's a possibility one of the injectors could just maybe pop off the rail and spray gasoline all over the place. If that happens, turn the key off and open the garage door until everything is dry.
Don't forget to lube your injector o-rings before putting them back in their holes.
+1 lol hopefully your fuel rail has some sort of clip that keeps the injector in place. vasoline works well for lubing the rubber prior to install
I'd guess it's just a little gas vapor that's hanging on the tip of the injector and works it's way up to the filter after shutdown... Very possible for a injector to fire just at shutdown but since the ign is now dead that fuel is never burned... A leaking injector would create a strong smell and likely cause slow starting when cold due to leak off of fuel pressure...
You could verify fuel pressure on the rail after setting overnight, but if it's just a slight odor on the filter and everything is performing as it should, I'd not be loosing sleep over it...
BTW injectors are generally held in place only by the rail... With rail loose and fuel pressure up, at least one will blow off the rail...
You could verify fuel pressure on the rail after setting overnight, but if it's just a slight odor on the filter and everything is performing as it should, I'd not be loosing sleep over it...
BTW injectors are generally held in place only by the rail... With rail loose and fuel pressure up, at least one will blow off the rail...
injectors getting stuck open were a big problem on the early 3V 5.4 engines. This would also cause a misfire, and raw fuel may or may not come out the tailpipe. I had one the injector was stuck open and caused the engine to bend a rod from hydrolock. Not saying this is your issue, just making you aware.
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