Ugh, drove with the gas cap open

dekaliber · 09-27-2010, 11:52 AM

Stupid confession:

I arrived at the track this weekend about 30 miles from where I filled up and noticed, much to my great chagrin, that my gas cap was off. The only possible explanation was that I simply forgot to cap off the tank after filling up (a first). I'm still pretty perplexed as to how I didn't notice this even in my mirror aside from the fact that it was very early in the morning and still dark.

Anyway, most of the drive was highway but about a 1/4 mile was over a gravel road where the cars in front of mine kicked up some pretty mighty clouds of dust. My car arrived with a light film of dust over it but the gas tank opening didn't look visibly dirty. However, I'm wondering if I should be considering changing out the fuel filter. Car is at about 18600 miles or so after the weekend.

Oddly enough, I didn't see that a fuel filter replacement was ever listed on either the Inspection I or Inspection II checklists -- is this supposed to be a "lifetime" part?

I haven't noticed anything negative in terms of performance. The engine felt strong and responsive both days and my fuel economy on the 3.5 hr drive back home seemed as good or better than it ever has been, so I'm wondering if I'm getting all worked up over nothing.

mfanatic325 · 09-27-2010, 12:25 PM

lol don't worry about it dude. I've never done this before, but I'm pretty darn sure there's nothing wrong with your car. You probably didn't notice the gas cap thing because the fuel door was probably slightly shut due to air turbulence when you were driving after the fill-up. In which case, you're even more safe, since the filler door probably by-passed over 90% of all the debris. Thennn you've got the actual little metal sliding plate where the fuel nozzle goes. That will act as your second "door" to block out debris. And fuel should be evaporating ever so slightly out of the uncapped portion of your filler. I would say all of that adds up to blocking almost 100% of all debris. So I wouldn't worry about this incident at all

Alicate · 09-27-2010, 02:01 PM

I failed to tighten mine properly and the computer threw a CEL light in less than a mile. I immediately stopped but after tightening it, it still took several cycles before it disappeared. Anyway, even if some dust entered your tank, the particles are very small and if not trapped by the filter, I don't think they would cause trouble.

bhoch · 09-27-2010, 02:37 PM

Quote:

Originally Posted by Alicate

I failed to tighten mine properly and the computer threw a CEL light in less than a mile. I immediately stopped but after tightening it, it still took several cycles before it disappeared. Anyway, even if some dust entered your tank, the particles are very small and if not trapped by the filter, I don't think they would cause trouble.

Not in my Z.. but in wife's 325ci we had the light on dash come on shortly after filling. took cap off/on twice and drive a little bit before it cleared. I am surprised you did not get a warning light on dash. Either way, you should be fine.

epbrown · 09-27-2010, 03:03 PM

Quote:

Originally Posted by dekaliber;

I haven't noticed anything negative in terms of performance. The engine felt strong and responsive both days and my fuel economy on the 3.5 hr drive back home seemed as good or better than it ever has been, so I'm wondering if I'm getting all worked up over nothing.

I bought my first Z4 in Des Moines and drove it back. About halfway home I discovered I had left the gas cap off. The CEL came on, but it had cycled off by the time I got home and I drove the car for two more years without incident.

Blind32 · 09-27-2010, 03:44 PM

Car is ruined, might as well sell it to me on the cheap

I think you should be fine. Little grit in the tank won't hurt much. God made dirt, dirt don't hurt. If it is large enough, it would get caught by the filter. Smaller stuff won't cause a problem.

pokeybritches · 09-27-2010, 04:52 PM

What's odd is we actually have a "check gas cap" light. The only time I've actually seen it illuminate was when I drove off from the gas station, saw my fuel door open, stopped and closed it... THEN the "check gas cap" light turned on. I turned off the car and restarted it - no light. Maybe it can only sense a change in the gas cap's state and not its position?

Swashplate · 09-27-2010, 06:17 PM

Well It might be harder than you think. Please correct me if I am wrong but isnt there a filter on the pump inlet that is inside the fuel tank. This is very common with most modern cars....

dekaliber · 09-27-2010, 10:18 PM

Yeah, weird thing is that my CEL never came on. I thought that it would if the cap was loose or not on at all. The last time I saw a CEL was on my '04 RX-8, and it was when I hadn't tightened the cap the full 3 clicks, so I'm surprised that it didn't come on in this case.

I guess my only concern was that if any crap got in the tank it would prematurely clog the fuel filter, but it sounds like I shouldn't be stressin'. Thanks everyone.

09-27-2010, 11:52 AM	#1
dekaliber Major 75 Rep 1,143 Posts Drives: '07 Z4MC, '11 JCW, '18 Z06 Join Date: Mar 2008 Location: Los Angeles iTrader: (1)	Ugh, drove with the gas cap open Stupid confession: I arrived at the track this weekend about 30 miles from where I filled up and noticed, much to my great chagrin, that my gas cap was off. The only possible explanation was that I simply forgot to cap off the tank after filling up (a first). I'm still pretty perplexed as to how I didn't notice this even in my mirror aside from the fact that it was very early in the morning and still dark. Anyway, most of the drive was highway but about a 1/4 mile was over a gravel road where the cars in front of mine kicked up some pretty mighty clouds of dust. My car arrived with a light film of dust over it but the gas tank opening didn't look visibly dirty. However, I'm wondering if I should be considering changing out the fuel filter. Car is at about 18600 miles or so after the weekend. Oddly enough, I didn't see that a fuel filter replacement was ever listed on either the Inspection I or Inspection II checklists -- is this supposed to be a "lifetime" part? I haven't noticed anything negative in terms of performance. The engine felt strong and responsive both days and my fuel economy on the 3.5 hr drive back home seemed as good or better than it ever has been, so I'm wondering if I'm getting all worked up over nothing.
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09-27-2010, 12:25 PM	#2
mfanatic325 ///M-fanatic 193 Rep 3,885 Posts Drives: '01 911 Turbo Join Date: Oct 2007 Location: Cupertino, CA. iTrader: (23)	lol don't worry about it dude. I've never done this before, but I'm pretty darn sure there's nothing wrong with your car. You probably didn't notice the gas cap thing because the fuel door was probably slightly shut due to air turbulence when you were driving after the fill-up. In which case, you're even more safe, since the filler door probably by-passed over 90% of all the debris. Thennn you've got the actual little metal sliding plate where the fuel nozzle goes. That will act as your second "door" to block out debris. And fuel should be evaporating ever so slightly out of the uncapped portion of your filler. I would say all of that adds up to blocking almost 100% of all debris. So I wouldn't worry about this incident at all
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09-27-2010, 02:01 PM	#3
Alicate Raw Conscript 0 Rep 37 Posts Drives: Z4M - E90M3 Join Date: Nov 2007 Location: USA iTrader: (0)	I failed to tighten mine properly and the computer threw a CEL light in less than a mile. I immediately stopped but after tightening it, it still took several cycles before it disappeared. Anyway, even if some dust entered your tank, the particles are very small and if not trapped by the filter, I don't think they would cause trouble.
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09-27-2010, 03:44 PM	#6
Blind32 Certified Adrenaline Junkie 43 Rep 1,325 Posts Drives: '07 Z4MC Join Date: Sep 2009 Location: Dallas TX iTrader: (2)	Car is ruined, might as well sell it to me on the cheap I think you should be fine. Little grit in the tank won't hurt much. God made dirt, dirt don't hurt. If it is large enough, it would get caught by the filter. Smaller stuff won't cause a problem.
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09-27-2010, 04:52 PM	#7
pokeybritches Colonel 480 Rep 2,782 Posts Drives: ESS/G-Power Z4M, VF Z4, 996tt Join Date: Sep 2009 Location: Los Angeles iTrader: (12) Garage List 2006 BMW Z4M [10.00] 2006 BMW Z4M [8.50] 2003 BMW Z4 3.0i [9.00]	What's odd is we actually have a "check gas cap" light. The only time I've actually seen it illuminate was when I drove off from the gas station, saw my fuel door open, stopped and closed it... THEN the "check gas cap" light turned on. I turned off the car and restarted it - no light. Maybe it can only sense a change in the gas cap's state and not its position?
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09-27-2010, 06:17 PM	#8
Swashplate Major 111 Rep 1,351 Posts Drives: in Anger. Join Date: Sep 2010 Location: Newcastle, WA iTrader: (2) Garage List 2009 Mercedes ML320 ... [0.00] 2013 BMW M5 [0.00] 2007 BMW M Coupe' [0.00]	Well It might be harder than you think. Please correct me if I am wrong but isnt there a filter on the pump inlet that is inside the fuel tank. This is very common with most modern cars.... __________________ Gone (2006 STI, 2008 EVO MR, 1968 Mustang) AFE Intake/Euro Cats/CSL Headers/Sportline CSL/H&R Springs 1217/1815 !!! BOILER UP !!!
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09-27-2010, 10:18 PM	#9
dekaliber Major 75 Rep 1,143 Posts Drives: '07 Z4MC, '11 JCW, '18 Z06 Join Date: Mar 2008 Location: Los Angeles iTrader: (1)	Yeah, weird thing is that my CEL never came on. I thought that it would if the cap was loose or not on at all. The last time I saw a CEL was on my '04 RX-8, and it was when I hadn't tightened the cap the full 3 clicks, so I'm surprised that it didn't come on in this case. I guess my only concern was that if any crap got in the tank it would prematurely clog the fuel filter, but it sounds like I shouldn't be stressin'. Thanks everyone.
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