CAMARO6 - View Single Post - Re-fuel with engine running?

00 Trans Ram · 01-20-2017, 09:44 AM

I think I'm going to throw something out there. Can anyone prove that leaving an engine running is MORE dangerous than stopping it? Or, stated another way, is leaving a machine in a constant state MORE dangerous than starting a car?

First off, I researched this last night, and was able to come up with exactly 1 case of a fire caused by a running motor with no contributory causes. However, I also saw exactly one case where a person restarted their car and caused a fire.

Think about it for a sec. What could cause a fire on a running car?

Exhaust pipes? Perhaps. Headers will be around 400-500* on a car. But, those headers will remain that temp for several minutes after you shut it down. So, stopping an engine won't help.

Exhaust gases? Not even close. Unless you have a leak at the heads, the temps coming out your tailpipe are barely 130*.

Electrical discharge? Hmmm - good question. Where are the electrical signals going when a car is running? Sparkplugs (high off the ground, and far away from the filler neck). Battery (inside trunk, or engine bay). Many other places, but few that are on the exterior of the car or near the ground.

But, there is one time when a high amount of electricity is sent to a location that is right near the ground, is exposed to atmosphere, and is in the middle of the car. It's when you engage the starter?

So, let's assume that there is a vapor or fluid leak (vapors hug the ground, so we'll treat them the same). It'll go under your car. If the engine is running, there's a slight chance that you will get a fire. But, that would mean the vapors would have to go up into your engine bay in sufficient quantity to combust. With the radiator fan probably running, that's gonna be tough. But, if there is gas under your car, and you hit the starter motor, there's a chance that the electricity could spark, or the gears could cause a spark when they engage.

I'll bet that, in some number of years, the "engine off" myth will go much the same way as cell phones on airplanes can cause a crash and cell phones cause fuel fires myths have gone.

https://www.pei.org/sites/default/fi...0Incidents.pdf

Study showing that, prior to 1999, fires at gas stations were thought to be caused by engines running, smoking, or lack of electrical continuity between the dispenser and nozzle. However, when they studied fires from 1999-2000, not one fire was caused by an engine running. All were caused by static, or unknown causes.

https://www.washingtonpost.com/archi...=.4079aa5c2494

Article that illustrates at least 1 case of a running engine causing a fire - it was a Ferrari where the engine was right next to the fill cap. But, there is also another case where an engine was off, and then started a fire when it was restarted (i.e. fire would not have occurred if engine was kept running). This case was a minivan, which is more similar to our cars (engine far away from refill point).

01-20-2017, 09:44 AM	#51
00 Trans Ram Drives: 2017 2SS Join Date: Jun 2014 Location: United States Posts: 636	I think I'm going to throw something out there. Can anyone prove that leaving an engine running is MORE dangerous than stopping it? Or, stated another way, is leaving a machine in a constant state MORE dangerous than starting a car? First off, I researched this last night, and was able to come up with exactly 1 case of a fire caused by a running motor with no contributory causes. However, I also saw exactly one case where a person restarted their car and caused a fire. Think about it for a sec. What could cause a fire on a running car? Exhaust pipes? Perhaps. Headers will be around 400-500* on a car. But, those headers will remain that temp for several minutes after you shut it down. So, stopping an engine won't help. Exhaust gases? Not even close. Unless you have a leak at the heads, the temps coming out your tailpipe are barely 130*. Electrical discharge? Hmmm - good question. Where are the electrical signals going when a car is running? Sparkplugs (high off the ground, and far away from the filler neck). Battery (inside trunk, or engine bay). Many other places, but few that are on the exterior of the car or near the ground. But, there is one time when a high amount of electricity is sent to a location that is right near the ground, is exposed to atmosphere, and is in the middle of the car. It's when you engage the starter? So, let's assume that there is a vapor or fluid leak (vapors hug the ground, so we'll treat them the same). It'll go under your car. If the engine is running, there's a slight chance that you will get a fire. But, that would mean the vapors would have to go up into your engine bay in sufficient quantity to combust. With the radiator fan probably running, that's gonna be tough. But, if there is gas under your car, and you hit the starter motor, there's a chance that the electricity could spark, or the gears could cause a spark when they engage. I'll bet that, in some number of years, the "engine off" myth will go much the same way as cell phones on airplanes can cause a crash and cell phones cause fuel fires myths have gone. https://www.pei.org/sites/default/fi...0Incidents.pdf Study showing that, prior to 1999, fires at gas stations were thought to be caused by engines running, smoking, or lack of electrical continuity between the dispenser and nozzle. However, when they studied fires from 1999-2000, not one fire was caused by an engine running. All were caused by static, or unknown causes. https://www.washingtonpost.com/archi...=.4079aa5c2494 Article that illustrates at least 1 case of a running engine causing a fire - it was a Ferrari where the engine was right next to the fill cap. But, there is also another case where an engine was off, and then started a fire when it was restarted (i.e. fire would not have occurred if engine was kept running). This case was a minivan, which is more similar to our cars (engine far away from refill point).