Fuel Dump Mystery - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Valkyrie14 · 01-30-2022, 08:07 AM

Parked last night with a full tank of gas. This morning smelled fuel in driveway. Go to get breakfast and notice tank is just above half. I stopped at gas station and looked under car at tank and fuel line. Nothing. Looked under hood and in-line pressure gauge read 42 (normal). And no fuel in engine bay.

Came home and looked at driveway and there was a ton of fuel on the ground. It wasn’t obvious at first, I live in WI and we have snow everywhere. I just left the car sit for an hour and no leaks. Tank is dry and no visible damage.

I have a camera on the driveway and there was no activity last night.

WTF? 8 gallons of gas got from my tank onto the ground and there is no evidence of it on the underside.

Valkyrie14 · 01-30-2022, 11:54 AM

I can’t get it to replicate the issue. I put cardboard under it all night and no leak. I let it idle for 15 minutes and no leaks.

I just drove around and it seems like I am going through a lot of gas. I also checked my CELs and I had a misfire code. I cleared it and a new code hasn’t thrown yet. My AFR gauge is showing a normal mix.

???

barkeater46 · 01-30-2022, 02:30 PM

Is it possible the suction line between tank and engine/pump is leaking ? Might be along left side mid-body and not near tank. A suction side leak may well continue to siphon long after shut down.

Valkyrie14 · 01-30-2022, 07:12 PM

Quote:

Originally Posted by barkeater46

Is it possible the suction line between tank and engine/pump is leaking ? Might be along left side mid-body and not near tank. A suction side leak may well continue to siphon long after shut down.

Totally possible. Right now I can’t get it to duplicate whatever happened. Might have something to do with a full tank. I haven’t filled it up since this happened. So if that is what is leaking I would see it underneath up by the driver’s door?

Batmanntexas · 01-31-2022, 08:08 AM

The fuel line runs along the passenger side of the car, so if there is a leak somewhere on the line itself, it should be showing on the passenger underside of the car.

Valkyrie14 · 01-31-2022, 02:10 PM

I have an AGP dual pump, with a new line. The system utilizes the OEM line as a return. No leaks shown there.

The previous post mentioned a line on the “left side” which I think of as the drivers side. But which is the left side depends on the person I suppose.

Update: I put in 10 gallons today which took me up to about 3/4 of a tank. Drove 25 miles and no issues. I think it was a fluke, but how in the hell did half a tank of gas end up on the ground!

Whoomba · 01-31-2022, 02:45 PM

Very frustrating

acutron42 · 01-31-2022, 02:45 PM

Any possibility that someone was trying to steal/siphon your gas? I had this happen to me years ago & luckily they caught the kid or I would not have known.

Edit: Sorry, I see that you had a camera.

Badbubba · 01-31-2022, 03:16 PM

There's an evap canister above the rear diff. Not sure how this system plays out with your modified fuel supply and return. This is where the vapors in your tank get displaced. Usually has charcoal in it to capture the vapors. The purge solenoid under the hood will then open to draw across the charcoal to remove the captured vapors and get burned. The canister will usually have a vent that opens to atmosphere in order to allow air across the carbon. There is also a fuel tank pressure sensor. The emission system monitors for a sealed system by running a vacuum check. Possibly over filled tank into canister, fuel siphoned through atmosphere valve on tank, because of failure or pressure. ????? Idk. Different vehicles have different systems, but this is the jist of fuel tank emission standards. May or may not have anything to do with what happened. Just throwing something out there.

Valkyrie14 · 02-01-2022, 09:58 AM

Quote:

Originally Posted by Badbubba

There's an evap canister above the rear diff. Not sure how this system plays out with your modified fuel supply and return. This is where the vapors in your tank get displaced. Usually has charcoal in it to capture the vapors. The purge solenoid under the hood will then open to draw across the charcoal to remove the captured vapors and get burned. The canister will usually have a vent that opens to atmosphere in order to allow air across the carbon. There is also a fuel tank pressure sensor. The emission system monitors for a sealed system by running a vacuum check. Possibly over filled tank into canister, fuel siphoned through atmosphere valve on tank, because of failure or pressure. ????? Idk. Different vehicles have different systems, but this is the jist of fuel tank emission standards. May or may not have anything to do with what happened. Just throwing something out there.

I have thought about something like this, I don’t know the complete system like you do or how it works. But when I filled up I was surprised by how many gallons it took. I think I had at least a gallon or more in the tank and I filled up almost 18 gallons. So as the theory goes, I over filled the tank to a point that gas went into a vapor canister that then created a vacuum without a free flow of air, thus pulling gas into a vent which dumped it on the ground.

What I like most about this theory, is that I don’t have to fix anything.

PaulsSS · 02-01-2022, 11:07 AM

Old gas story: Neighbor bought a new car, next door jealous neighbor decides to mess with him by adding a few gallons of gas to his car every week. So for a few months he doing this. New car neighbor is getting great gas mileage UNTIL jealous neighbor stops putting gas in his tank every week. New car neighbor is back at the car dealer complaining and driving them nuts. True story told to me by a GM factory rep...................

Valkyrie14 · 02-01-2022, 06:22 PM

Quote:

Originally Posted by PaulsSS

Old gas story: Neighbor bought a new car, next door jealous neighbor decides to mess with him by adding a few gallons of gas to his car every week. So for a few months he doing this. New car neighbor is getting great gas mileage UNTIL jealous neighbor stops putting gas in his tank every week. New car neighbor is back at the car dealer complaining and driving them nuts. True story told to me by a GM factory rep...................

That is some funny sh*t.

ADVMax · 02-01-2022, 06:39 PM

Quote:

Originally Posted by Valkyrie14

That is some funny sh*t.

I’ve made many people scramble around their BMW motorcycles on all 4’s like a big bug looking up under the engine after dumping a little puddle of used oil under it.

I’m terrible I know but……….

Someone above I believe mentioned full tank, leak out of a vent……seems plausible. Were you parked flat or on a hill? Can’t remember if you said? I got CRS.

1JEWLDSSRS · 02-01-2022, 07:08 PM

Quote:

Originally Posted by ADVMax

I’ve made many people scramble around their BMW motorcycles on all 4’s like a big bug looking up under the engine after dumping a little puddle of used oil under it.

I’m terrible I know but……….

Someone above I believe mentioned full tank, leak out of a vent……seems plausible. Were you parked flat or on a hill? Can’t remember if you said? I got CRS.

Camaro Retention Syndrome??? lol.

01-30-2022, 08:07 AM	#1
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	Fuel Dump Mystery Parked last night with a full tank of gas. This morning smelled fuel in driveway. Go to get breakfast and notice tank is just above half. I stopped at gas station and looked under car at tank and fuel line. Nothing. Looked under hood and in-line pressure gauge read 42 (normal). And no fuel in engine bay. Came home and looked at driveway and there was a ton of fuel on the ground. It wasn’t obvious at first, I live in WI and we have snow everywhere. I just left the car sit for an hour and no leaks. Tank is dry and no visible damage. I have a camera on the driveway and there was no activity last night. WTF? 8 gallons of gas got from my tank onto the ground and there is no evidence of it on the underside. __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

01-30-2022, 11:54 AM	#2
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	I can’t get it to replicate the issue. I put cardboard under it all night and no leak. I let it idle for 15 minutes and no leaks. I just drove around and it seems like I am going through a lot of gas. I also checked my CELs and I had a misfire code. I cleared it and a new code hasn’t thrown yet. My AFR gauge is showing a normal mix. ??? __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

01-31-2022, 08:08 AM	#5
Batmanntexas Drives: 2012 Camaro SS (2SS) Join Date: Aug 2012 Location: Stafford, VA Posts: 1,374 View My Garage	The fuel line runs along the passenger side of the car, so if there is a leak somewhere on the line itself, it should be showing on the passenger underside of the car. __________________ 745RWHP/634RWTQ on 93 @ 10psi 806/676 on E85 @ 10psi COTW 9/8/14

01-31-2022, 02:10 PM	#6
Valkyrie14 Valkyrie14 Drives: Chevrolet Camaro SS Join Date: Mar 2020 Location: Eau Claire, Wisconsin Posts: 962	I have an AGP dual pump, with a new line. The system utilizes the OEM line as a return. No leaks shown there. The previous post mentioned a line on the “left side” which I think of as the drivers side. But which is the left side depends on the person I suppose. Update: I put in 10 gallons today which took me up to about 3/4 of a tank. Drove 25 miles and no issues. I think it was a fluke, but how in the hell did half a tank of gas end up on the ground! __________________ 2014 SS LS3/LSA Supercharger, 10% Super Damper, 2.55 upper, AGP Dual Pump, ID 1050 injectors, Pegasus solid rear cradle bushings, LT Headers, Roto-Fab CAI, Elite E2 catch can, E85 corn fed, 160 Thermostat, Monster Twin Disk, MGW Short Throw shifter, Tick Clutch Master Cylinder, HP Tuners, JL Audio system.

01-31-2022, 02:45 PM	#8
acutron42 Drives: 2013 Camaro 2SS AGM Join Date: Apr 2020 Location: WNY Posts: 733	Any possibility that someone was trying to steal/siphon your gas? I had this happen to me years ago & luckily they caught the kid or I would not have known. Edit: Sorry, I see that you had a camera. Last edited by acutron42; 01-31-2022 at 03:43 PM.

01-30-2022, 02:30 PM	#3
barkeater46 Drives: 2010 Camaro 2LT/RS Join Date: Jul 2021 Location: Central New York Posts: 81 View My Garage	Is it possible the suction line between tank and engine/pump is leaking ? Might be along left side mid-body and not near tank. A suction side leak may well continue to siphon long after shut down.

01-31-2022, 02:45 PM	#7
Whoomba Drives: 2024Camaro 2SS CE Convertible Join Date: Jul 2013 Location: Texas Posts: 1,302	Very frustrating

01-31-2022, 03:16 PM	#9
Badbubba GrINned & JUICEd Drives: 15STI, 10Expy, 10 2SS/RS M6, 47KB1 Join Date: Nov 2009 Location: Pittsburgh, PA Posts: 1,247	There's an evap canister above the rear diff. Not sure how this system plays out with your modified fuel supply and return. This is where the vapors in your tank get displaced. Usually has charcoal in it to capture the vapors. The purge solenoid under the hood will then open to draw across the charcoal to remove the captured vapors and get burned. The canister will usually have a vent that opens to atmosphere in order to allow air across the carbon. There is also a fuel tank pressure sensor. The emission system monitors for a sealed system by running a vacuum check. Possibly over filled tank into canister, fuel siphoned through atmosphere valve on tank, because of failure or pressure. ????? Idk. Different vehicles have different systems, but this is the jist of fuel tank emission standards. May or may not have anything to do with what happened. Just throwing something out there. __________________ GPI SS3 Cam & stuff,N.O. Plate(dedicated fuel tank,progressive,fuel hose upgrade,remote opener,heater,console switches),LNC2000,CTAP,ARH 1 7/8" LTs/gutted cats/X pipe/mufflers,Jet Hot coated LTs,GPI HPT Tune,CAI, Scoop,Rx Catch Can,Gates heater hose relocation, Remote clutch & auto brake res,Metco loop,Momentum Tunnel Brace,TSW Nurb 18",555 & 05,Pfadt trailing arms & toe rods,Autometer WB,Fesler Pillar Pod,LED strips (int),Lloyds floor & trunk mats,LED DRL/front turn & license plate,DRL harness,VLEDs tail lights,Plasticoat Bowties. Ord: Oct 5, 2009 Rec: Nov 19, 2009 13.17@112.6 stock

02-01-2022, 11:07 AM	#11
PaulsSS Drives: 15SS Camaro Join Date: Dec 2020 Location: US Posts: 346	Old gas story: Neighbor bought a new car, next door jealous neighbor decides to mess with him by adding a few gallons of gas to his car every week. So for a few months he doing this. New car neighbor is getting great gas mileage UNTIL jealous neighbor stops putting gas in his tank every week. New car neighbor is back at the car dealer complaining and driving them nuts. True story told to me by a GM factory rep...................