# Question for Car Gurus



## CohibaRobusto (Dec 9, 2021)

So my 16 yr old daughter just started driving, and despite me showing her how to fuel up multiple times, on the way home today she put 1.5 gallons of diesel in our gas 2013 Honda Pilot, before someone stopped her.

She called and I told her to fill it up the rest of the way with unleaded and drive it home. I think she put about 15 gallons of unleaded.

I figure it's a low enough concentration and will just burn off, but let me know if I'm wrong and I can siphon.


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## CJ (Dec 9, 2021)

CohibaRobusto said:


> So my 16 yr old daughter just started driving, and despite me showing her how to fuel up multiple times, on the way home today she put 1.5 gallons of diesel in our gas 2013 Honda Pilot, before someone stopped her.
> 
> She called and I told her to fill it up the rest of the way with unleaded and drive it home. I think she put about 15 gallons of unleaded.
> 
> I figure it's a low enough concentration and will just burn off, but let me know if I'm wrong and I can siphon.


No bueno, drain it.

The Googles says it will fukk your car up.


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## Kalicut (Dec 9, 2021)

CohibaRobusto said:


> So my 16 yr old daughter just started driving, and despite me showing her how to fuel up multiple times, on the way home today she put 1.5 gallons of diesel in our gas 2013 Honda Pilot, before someone stopped her.
> 
> She called and I told her to fill it up the rest of the way with unleaded and drive it home. I think she put about 15 gallons of unleaded.
> 
> I figure it's a low enough concentration and will just burn off, but let me know if I'm wrong and I can siphon.


It won’t run, just drain the system and fill it completely full of gas and fuel system cleaner change all fuel filters should be fine. If you put gas in a diesel you will literally explode the motor. Diesel take compression to ignite, gas takes spark, you’ll flood the system and it’ll never ignite on a gas engine


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## Kalicut (Dec 9, 2021)

here’s a better example, starting a fire with gas it starts instantly with a big fire ball, start it with diesel it starts really slow with no fire ball. You can literally pour diesel onto an open fire and it’ll never run back up the can.


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## CohibaRobusto (Dec 9, 2021)

Kalicut said:


> It won’t run, just drain the system and fill it completely full of gas and fuel system cleaner change all fuel filters should be fine. If you put gas in a diesel you will literally explode the motor. Diesel take compression to ignite, gas takes spark, you’ll flood the system and it’ll never ignite on a gas engine


Even though it's only like 5% diesel in the tank? It's running and sounds fine.

It's a 21 gal tank with about 1.5 gal diesel


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## Kalicut (Dec 9, 2021)

CohibaRobusto said:


> Even though it's only like 5% diesel in the tank? It's running and sounds fine.


To be safe I would, filters and fuel treatment won’t cost much at all, besides it’s really good practice to do it so often.


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## CohibaRobusto (Dec 9, 2021)

Ok


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## shackleford (Dec 9, 2021)

im no expert but i feel like it should be fine

the worst that could happen is it looses some power, right? it cant be worse than water in fuel, its still combustible.


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## shackleford (Dec 9, 2021)

i mean, some engine run on fryer oil for petes sake. lol

but like @Kalicut said, if it was the other way around, i would be more concerned about predetonation, or whatever the technical term would be.


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## Kalicut (Dec 9, 2021)

shackleford said:


> i mean, some engine run on fryer oil for petes sake. lol
> 
> but like @Kalicut said, if it was the other way around, i would be more concerned about predetonation, or whatever the technical term would be.


I like small words. blow up works great.


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## shackleford (Dec 9, 2021)

Kalicut said:


> I like small words. blow up works great.


at least the top end will be lubed up from the diesel oil running through it  
@CohibaRobusto i think you'll be fine.


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## A B C XYZ (Dec 9, 2021)

CohibaRobusto said:


> So my 16 yr old daughter just started driving, and despite me showing her how to fuel up multiple times, on the way home today she put 1.5 gallons of diesel in our gas 2013 Honda Pilot, before someone stopped her.
> 
> She called and I told her to fill it up the rest of the way with unleaded and drive it home. I think she put about 15 gallons of unleaded.
> 
> I figure it's a low enough concentration and will just burn off, but let me know if I'm wrong and I can siphon.


I would be ashamed to have a kid that stupid.


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## CJ (Dec 9, 2021)

What Really Happens When You Put Diesel in a Gas Car?
					

What's the worst that can happen to your car if you mix up the diesel and the gasoline? And does this happen a lot? Car Talk has the answer, here.




					www.cartalk.com


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## nissan11 (Dec 9, 2021)

I'd keep driving it. I dont think 5% diesel will make a difference. Its not like she put DEF in it 

Sent from my SM-G975U using Tapatalk


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## 69nites (Dec 9, 2021)

If it's not even running rough it's fine. No smoke, no misfire, no problem.

Nothing is going to blow up because there's some diesel in there. You'll at worst be getting an incomplete burn. 

They really need to stop having diesel with gas nozzles at gas stations. If that had a proper nozzle it wouldn't have even fit.


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## NbleSavage (Dec 9, 2021)

A B C XYZ said:


> I would be ashamed to have a kid that stupid.


We try not to bag on people's families round here, Mate.


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## Kalicut (Dec 9, 2021)

nissan11 said:


> I'd keep driving it. I dont think 5% diesel will make a difference. Its not like she put DEF in it
> 
> Sent from my SM-G975U using Tapatalk


Now def is a different story


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## Yano (Dec 9, 2021)

To me it's odd that it even fit in the car, owned a diesel F250 for a long time and the fuel pump nozzles are 1" internal , 1" 3/16ths outer normally , it shouldn't of even fit in the cars fuel fill hole where that flap is that keeps it from back splashing.


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## Kalicut (Dec 9, 2021)

Yano said:


> To me it's odd that it even fit in the car, owned a diesel F250 for a long time and the fuel pump nozzles are 1" internal , 1" 3/16ths outer normally , it shouldn't of even fit in the cars fuel fill hole where that flap is that keeps it from back splashing.


That changed them at standard pumps, if you go to a fuel island at a truck stop they’re still over sized


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## Geezer (Dec 9, 2021)

A B C XYZ said:


> derp


Stay classy


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## Adrenolin (Dec 9, 2021)

1.5 gallons ain't a big deal on a 21gallon filled tank.  A bottle of VP Racing's Octanium unleaded will ensure you have high enough octane to prevent knock (predetonation).


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## CJ (Dec 9, 2021)

Adrenolin said:


> 1.5 gallons ain't a big deal on a 21gallon filled tank.  A bottle of VP Racing's Octanium unleaded will ensure you have high enough octane to prevent knock (predetonation).


From what I'm seeing, it's not really the octane that's the issue, that's easily fixable, but it's the thickness. It says it will clog the fuel filter and injectors, and they'll have to be taken out and cleaned.

Seems like an unnecessary risk, it's easy to drain a fuel tank.


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## A B C XYZ (Dec 9, 2021)

CJ275 said:


> From what I'm seeing, it's not really the octane that's the issue, that's easily fixable, but it's the thickness. It says it will clog the fuel filter and injectors, and they'll have to be taken out and cleaned.
> 
> Seems like an unnecessary risk, it's easy to drain a fuel tank.


The viscosity of the diesel is going to instantly change once it's mixed in with the gasoline. The answer lies within the ratio.  How much gas, vs how much diesel.


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## CJ (Dec 9, 2021)

A B C XYZ said:


> The viscosity of the diesel is going to instantly change once it's mixed in with the gasoline. The answer lies within the ratio.  How much gas, vs how much diesel.


Diesel is more dense than gasoline, it will sink.


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## A B C XYZ (Dec 9, 2021)

CJ275 said:


> Diesel is more dense than gasoline, it will sink.


Just because it's more dense does not mean it won't dilute.


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## CJ (Dec 9, 2021)




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## CJ (Dec 9, 2021)

A B C XYZ said:


> Just because it's more dense does not mean it won't dilute.


Doesn't mean it will either. Oil and water, oil and vinegar, Bass and Guinness, etc...


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## Samp3i (Dec 9, 2021)

CohibaRobusto said:


> Even though it's only like 5% diesel in the tank? It's running and sounds fine.
> 
> It's a 21 gal tank with about 1.5 gal diesel


It's fine. My ex gf has done it and it was all fine. The concentration is minimal.

Your daughter should learn how to fuel a fucking car before driving it.
Send her walking for a week she will learn.


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## A B C XYZ (Dec 9, 2021)

Gasoline needs to have an octane rating of 87-91 to fit today's car engines. Diesel fuel has an octane rating of 25-40. Mixing *2% diesel fuel into gasoline will lower the overall octane rating by 1 point*. Getting 10% diesel contamination lowers octane by 5 points, which is enough to create problems in most engines.


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## CJ (Dec 9, 2021)

A B C XYZ said:


> Gasoline needs to have an octane rating of 87-91 to fit today's car engines. Diesel fuel has an octane rating of 25-40. Mixing *2% diesel fuel into gasoline will lower the overall octane rating by 1 point*. Getting 10% diesel contamination lowers octane by 5 points, which is enough to create problems in most engines.


Octane rating has ZERO to do with clogging filters and injectors. It's how much pressure it can withstand before igniting.


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## nissan11 (Dec 9, 2021)

Gas mixes with diesel just fine. We mix gas to diesel at work for wildland fire torches. 
If you are really worried, now that it is diluted, run a hose down the fill tube and pump it out. Then whatever diesel is left will be very very diluted. But shit, dont drop the fuel tank and try to drain it that way. That is too much work.

Sent from my SM-G975U using Tapatalk


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## Adrenolin (Dec 9, 2021)

CJ275 said:


> From what I'm seeing, it's not really the octane that's the issue, that's easily fixable, but it's the thickness. It says it will clog the fuel filter and injectors, and they'll have to be taken out and cleaned.
> 
> Seems like an unnecessary risk, it's easy to drain a fuel tank.


I don't think it would clog injectors or the fuel filter from a one time occasion unless they were already on the verge of being clogged. If you do it a few times, I'd suspect the chances of gunking up your injectors would go up drastically, but not from a single time with a small amount of diesel, especially if you use an octane booster with the extra fuel detergents and cleaners like I suggested above. 

But yes a drain and refill would obviously be the safest route.


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## shackleford (Dec 9, 2021)

nissan11 said:


> Gas mixes with diesel just fine. We mix gas to diesel at work for wildland fire torches.
> If you are really worried, now that it is diluted, run a hose down the fill tube and pump it out. Then whatever diesel is left will be very very diluted. But shit, dont drop the fuel tank and try to drain it that way. That is too much work.
> 
> Sent from my SM-G975U using Tapatalk


you do wildland? a few coworkers of mine are part of a state team and deploy out west occasionally. those wildland guys earn their pay for sure.


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## nissan11 (Dec 9, 2021)

shackleford said:


> you do wildland? a few coworkers of mine are part of a state team and deploy out west occasionally. those wildland guys earn their pay for sure.


I have my hands in all kind of shit.

Sent from my SM-G975U using Tapatalk


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## CJ (Dec 9, 2021)

nissan11 said:


> I have my hands in all kind of shit.
> 
> Sent from my SM-G975U using Tapatalk


So doesn't you're gf...or at least her fingers.  😘


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## shackleford (Dec 9, 2021)

nissan11 said:


> I have my hands in all kind of shit.
> 
> Sent from my SM-G975U using Tapatalk


sounds like a good time! share some of that fire porn!


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## nissan11 (Dec 9, 2021)

I don't keep a lot of fire pics but here are a few. 
	

	
	
		
		

		
			























Sent from my SM-G975U using Tapatalk


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## Dnewell2004 (Dec 9, 2021)

CohibaRobusto said:


> So my 16 yr old daughter just started driving, and despite me showing her how to fuel up multiple times, on the way home today she put 1.5 gallons of diesel in our gas 2013 Honda Pilot, before someone stopped her.
> 
> She called and I told her to fill it up the rest of the way with unleaded and drive it home. I think she put about 15 gallons of unleaded.
> 
> I figure it's a low enough concentration and will just burn off, but let me know if I'm wrong and I can siphon.


It's a Honda. Let her eat lol. It'll run for-ev-er

Sent from my SM-N986U using Tapatalk


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## shackleford (Dec 9, 2021)

nissan11 said:


> I don't keep a lot of fire pics but here are a few.
> 
> 
> 
> ...


great pics man


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## CohibaRobusto (Dec 9, 2021)

69nites said:


> .
> 
> They really need to stop having diesel with gas nozzles at gas stations. If that had a proper nozzle it wouldn't have even fit.


Yeah I was wondering how she even pumped it because I thought all diesel nozzles were oversized.


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## Samp3i (Dec 9, 2021)

CohibaRobusto said:


> Yeah I was wondering how she even pumped it because I thought all diesel nozzles were oversized.


Women are expert in fitting oversized stuff


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## CohibaRobusto (Dec 9, 2021)

CJ275 said:


>


This was a good video. Clearly though, the gas mixed with the diesel pretty well and acted like a solvent. Also shortly after that he talked about mix ratios that were dangerous and they were much higher like 50/50.


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## CJ (Dec 9, 2021)

CohibaRobusto said:


> This was a good video. Clearly though, the gas mixed with the diesel pretty well and acted like a solvent. Also shortly after that he talked about mix ratios that were dangerous and they were much higher like 50/50.


You must have stopped watching before the 4:45-5:05 time period.

Ultimately it's your car, you decide the risk level you're willing to take.


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## CohibaRobusto (Dec 9, 2021)

CJ275 said:


> You must have stopped watching before the 4:45-5:05 time period.
> 
> Ultimately it's your car, you decide the risk level you're willing to take.


Well he's talking about a 50/50 ratio in that sound byte you're mentioning.

I'm going to try to siphon it this afternoon, because it just so happens I own an electric fuel siphon, so it could be very easy. I have empty gas cans also and a disposal site nearby. The problem is a lot of cars have screens in the line going to the tank to prevent siphoning. So if I have one of those, it dramatically makes the job much more complicated.


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## Kalicut (Dec 9, 2021)

What needs to happen is people with gas cars stop using the pumps that offer diesel. It take me forever to get to the pump because of this.


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## Kraken (Dec 9, 2021)

Samp3i said:


> Your daughter should learn how to fuel a fucking car before driving it.
> Send her walking for a week she will learn.


Says the expert on child rearing. 



CJ275 said:


> So doesn't you're gf...or at least her fingers.  😘


Damn, beat me to it!


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## CohibaRobusto (Dec 10, 2021)

Well the tank has a screen blocking the siphon, so it looks like I'm going to try running it through.  

I'll dilute it some more when I get through a quarter of the tank.


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## shackleford (Dec 10, 2021)

CohibaRobusto said:


> Well the tank has a screen blocking the siphon, so it looks like I'm going to try running it through.
> 
> I'll dilute it some more when I get through a quarter of the tank.


i think it'll be just fine


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## LocalGymRat (Dec 10, 2021)

NbleSavage said:


> We try not to bag on people's families round here, Mate.


Agreed, kids fuck up. You learn from early mistakes. Respect the members and their loved ones


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## 69nites (Dec 10, 2021)

CohibaRobusto said:


> Yeah I was wondering how she even pumped it because I thought all diesel nozzles were oversized.


Often times gas stations that aren't designed for big rigs just use a gas nozzles and pumps. It's pretty annoying because they also pump at gasoline speeds so if you have big tanks it takes forever.


CohibaRobusto said:


> Well the tank has a screen blocking the siphon, so it looks like I'm going to try running it through.
> 
> I'll dilute it some more when I get through a quarter of the tank.


If you really want to get the fuel out just pull a fuel line and run it into your container, jump the fuel pump relay. Just make sure not to run the pump dry.


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## nissan11 (Dec 10, 2021)

69nites said:


> Often times gas stations that aren't designed for big rigs just use a gas nozzles and pumps. It's pretty annoying because they also pump at gasoline speeds so if you have big tanks it takes forever.
> 
> If you really want to get the fuel out just pull a fuel line and run it into your container, jump the fuel pump relay. Just make sure not to run the pump dry.


Why would he need to jump the relay instead of just turning the key to start priming the system?

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## 69nites (Dec 11, 2021)

After 3 seconds the fuel pump turns off if you don't start the car.


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## Hughinn (Dec 11, 2021)

CohibaRobusto said:


> Even though it's only like 5% diesel in the tank? It's running and sounds fine.
> 
> It's a 21 gal tank with about 1.5 gal diesel


Man, don't listen to these Google experts. 

It'll be okay. 

But, you'll want to change your fuel filters early, and I'd run some injector cleaner through it for the next few tank's. 

I've mixed desiel and gas before.  Don't panic.


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## Hughinn (Dec 11, 2021)

CohibaRobusto said:


> Well he's talking about a 50/50 ratio in that sound byte you're mentioning.
> 
> I'm going to try to siphon it this afternoon, because it just so happens I own an electric fuel siphon, so it could be very easy. I have empty gas cans also and a disposal site nearby. The problem is a lot of cars have screens in the line going to the tank to prevent siphoning. So if I have one of those, it dramatically makes the job much more complicated.




You ain't siphoning it through the fill cap.  It'll have a screen in it. 

Dude, don't trip on it.   It'll be fine. 

Run some fuel injector cleaner for the next tank or two amd relax. 

You'll want to change the file filter pretty soon but it's going to be okay.


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## A B C XYZ (Dec 11, 2021)

Hughinn said:


> You ain't siphoning it through the fill cap.  It'll have a screen in it.
> 
> Dude, don't trip on it.   It'll be fine.
> 
> ...


Yup... the diesel will probably clean it in certain ways also.

I would not even mess with injector cleaner.


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## shackleford (Dec 13, 2021)

How's the car running @CohibaRobusto


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## CohibaRobusto (Dec 14, 2021)

shackleford said:


> How's the car running @CohibaRobusto


Pretty good still. I think it will be fine. I'm going to  get the fuel filter changed and have it all flushed after the holidays.


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## FlyingPapaya (Dec 14, 2021)

A B C XYZ said:


> I would be ashamed to have a kid that stupid.


Not cool shit bag


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## FlyingPapaya (Dec 14, 2021)

CohibaRobusto said:


> Pretty good still. I think it will be fine. I'm going to  get the fuel filter changed and have it all flushed after the holidays.


Change it yourself. All you need is the little tool to push the clip in. Takes like 5 minutes and saves you tons.


			https://www.autozone.com/test-scan-and-specialty-tools/fuel-line-disconnect-tool/p/oemtools-zinc-fuel-line-disconnect-tool/246367_0_0?cmpid=LIA:US:EN:AD:NL:1000000:TLS:8367255572&gclid=Cj0KCQiAnuGNBhCPARIsACbnLzpLbk5Bx6Dw1SjyaCuChjPrgHksLYEq4IJ7h_jbnaN9TEO_BWM0LXEaAiCbEALw_wcB&gclsrc=aw.ds
		


Off chance it's a weird size








						Fuel Line and A/C Quick Disconnect Tool, 6 Piece
					

Amazing deals on this Fuel Line And A/C Quick Disconnect Tool at Harbor Freight. Quality tools & low prices.




					www.harborfreight.com


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## FlyingPapaya (Dec 14, 2021)

And I googled. It's in tank... Nm that sucks
I'd still do it myself. Just more time consuming.
What a shitty design. Mines backside of motor against firewall. Lol https://www.piloteers.org/threads/fuel-filter-location.166137/
Eeek


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## nissan11 (Dec 14, 2021)

Hughinn said:


> You ain't siphoning it through the fill cap. It'll have a screen in it.
> 
> Dude, don't trip on it. It'll be fine.
> 
> ...


Where specifically is the screen on the honda pilot? I've never seen one in the fill pipe assembly on this model. 

Sent from my SM-G975U using Tapatalk


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## 69nites (Dec 14, 2021)

There is no reason to change the fuel filter just because you had a gallon of diesel go through the system.





FlyingPapaya said:


> And I googled. It's in tank... Nm that sucks
> I'd still do it myself. Just more time consuming.
> What a shitty design. Mines backside of motor against firewall. Lol https://www.piloteers.org/threads/fuel-filter-location.166137/
> Eeek


Sock filters on the pickup sending unit used to be all the rage.


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## CohibaRobusto (Dec 14, 2021)

nissan11 said:


> Where specifically is the screen on the honda pilot? I've never seen one in the fill pipe assembly on this model.
> 
> Sent from my SM-G975U using Tapatalk


Seemed like it was close to the tank because I got the siphon tube down pretty far before something was blocking it. Or maybe it wasn't a screen, but there was definitely some type of obstruction.


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## Hughinn (Dec 14, 2021)

nissan11 said:


> Where specifically is the screen on the honda pilot? I've never seen one in the fill pipe assembly on this model.
> 
> Sent from my SM-G975U using Tapatalk



Not sure about a Honda pilot.  I've never owned an import.

But, it'll be in the fill neck just before the tank, or else just after your tank cap. 

That's where they all are.


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## Tazz (Dec 14, 2021)

Hughinn said:


> Not sure about a Honda pilot. I've never owned an import.
> 
> But, it'll be in the fill neck just before the tank, or else just after your tank cap.
> 
> That's where they all are.



At this point, siphoning out 17 gallons will be a pain in the ass. 

You can get an electric siphon pump on amazon though if you’re worried.

I think you should be fine, might of been better if she filled it up with premium after, but take my advice with a grain of salt, you should call a Honda dealership and just see what they can tell you on the phone as free advice, and call a garage mechanic shop too, see what both their perspectives are. 

Just don’t get suckered into paying $300 for some crazy bullshit.


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## In2Deep (Apr 3, 2022)

You can just run it through. Your talking less than 10% if you top off the fuel tank. Are you sure it wasn't E85 because a diesel nozzle is bigger in diameter than gas/petrol. Usually you can fit a gas nozzle in diesel but not the other way around.


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## CohibaRobusto (Apr 4, 2022)

So I never followed up on this, but I think I should. It was ideling a little rought after a while and the dealership ended up changing the plugs, fuel filter and I don't remember what else. It's fine now, but it was a little pricey. Didn't do any permanent damage though.


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## shackleford (Apr 4, 2022)

CohibaRobusto said:


> So I never followed up on this, but I think I should. It was ideling a little rought after a while and the dealership ended up changing the plugs, fuel filter and I don't remember what else. It's fine now, but it was a little pricey. Didn't do any permanent damage though.


Awesome, thanks for the follow up, I was wondering after I saw the thread bumped Glad it turned out better than worse


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## chicago311 (Jan 4, 2023)

put a bottle of heet in it, and drive the car and each time it goes down to 3/4 of a tank  refill it and just keep filling it like that and you will be fine, i know a few people that has used diesel in gas cars and the advise i gave them is the same as im giving you, and everything is fine with their cars.  you also can syferin the gas out and refill it that away also.


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## Clyde (Jan 4, 2023)

OK, a bit late but just noticed this...

Mixing diesel with gas will profoundly lower the octane rating, even just a small amount. This could result in uncontrolled detonation (pinging). Detonation has the potential to break piston ring lands and has the potential to destroy pistons.

Diesel fuel is rated in cetane (lower heat to light off), the higher the better. It's pretty much the opposite of octane (resistance to detonation) rating.

That said, most modern engines with ECU's have detonation sensors, and will adjust things on the fly to eliminate it. The results would only be reduced power.

I'd drain the tank and if it was my car. The ECU can only do so much to eliminate detonation. If the system is designed for a min of say 89 octane, and you're running 80 or less, it wouldn't be worth it.

BTW, op how'd this turn out?


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