Putting Gasoline In A Diesel Car - What Happens? (2023)


What happens if you put gasoline in a diesel car? What if I put gas in my diesel truck? What if you put diesel fuel in a gas car? We'll walk through all of the components, the fuel tank, in-tank pump, fuel filter, electronic pump, high pressure pump, fuel rail, and fuel injectors to talk about what damage might occur, and what you can expect the dealer to replace.

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Hands of more than hello.

Everyone and welcome this really talking about what happens when you put gasoline in a diesel car now, why you do this, you know, there's, not really a good reason, but someone might know by accident or maybe intentionally, or maybe they just didn't know when they thought any fuel work.

Absolutely, you know, we've seen sort of all the range of people, miss fueling their cars anything from some gas stations have green punk covers for diesel and some have yellow.

So that's, a confusing thing we had a customer is low in their car out to their friend.

And the first tho up their friends doing a real nice thing, build their little their car tomorrow, their car, and they did a real nice thing by friends and their friends filled their car with gasoline on the very first bill up.

And we've even had where they just didn't want to they did it very possible? Sometimes you don't want the details.

But the point is is that you've actually dealt with this shop anytime, you know, you have to take care of it.

And so we're gonna do is walk through the different components and what will fail and what you'll have to deal with when the customer brings in the car that has done this yet so get started with the fuel tank.

Does anything bad happen if I stick diesel fuel and gasoline in a diesel tank generally with the tank itself? Nothing bad happens.

It's it's, a plastic tank.

So not really plastic, but composite it's, a composite.

Thank you.

And it holds up just fine to gasoline.

What we will do is remove the in-tank pump and clean any remaining gasoline out of the tank.


Now that in turn pump as you mentioned as anything having with that are you? Can you still reuse it? Most of the time you can reuse the in-tank pump.

It really depends on how much gasoline was pumped through it isn't that usually depends on how long the car was cranked.

Well, not starting because it was ok.

So from that intent, palm pilots traveling through some people lie to the filter.

And as far as a few lines themselves is there any problem with gasoline and diesel fuel lines.

Now these lines we actually will replace these are under headlines.

The lines from the tank up into the engine compartment.

We won't replace those generally will flush that would break cleaning compressed air to get gasoline.

But usually those holed up just fine.

But once we get to the fuel filter housing, we do replace the entire housing as well as the filter.

You can see there's valving inside of the filter housings.

We want to make sure we don't leave any gasoline inside of that as well as the rubber lines due to possible gasoline containing any problem with using brake cleaner through those those lines, you know, we're, not leaving it sitting there for any length of time, it's spray, very clean, and then compressed error rate.

So the fuel filter itself does this have to get replaced just comes as an assembly.

So we replace all of it it's got the filter been ok to it.

So from the fuel filter, we move on to the electronic pump.

What happens when you got gasoline in this with gasoline inside the electronic pump, it isn't able to have the lubricating properties like diesel fuel? Does so we go ahead and replace that not only you know, a lot of the stuff is we replaced.

It may not be let's say dead today, but we worry about long-term effects, right? So essentially what you're doing it when you put that gasoline is increasing the wear rate for that duration and decreasing the lubrication properties.

Yes, I.

These pumps, ok, that makes sense.

So from here, we travel to the high pressure pump right here.

We travel.

We go to the high pressure pump.

This is what jumps obviously, the fuel pressure up their driven by the timing belt.

This one did have metal contamination, what will generally do very first thing to do? This is a car that had the wrong fuel in it.

Yes, this is out of a car that had the wrong fuel in it as well as a technician that tried to cut apart.

I might be the technician.

So what happens with this you replace this? We absolutely replace this.

This is usually where the metal fragments come from it's, a failure of this pump internally.

And what we'll do is we'll pull this valve off the top of the pump.

And as you take the pump valve off, the pump you'll see embedded in the screen metal particles of metal particles coming from coming from this pump.

This point of failure and like all of the components in here, what what's what's wearing actually ever had a part in it could be bearing material cause remember we're not having anything to lubricate these parts like we do when we had diesel any of the components of metal-on-metal contact, your gonna be having more where because you don't have the lubrication for the diesel fuel.

And most of these actually do have to go back to the manufacturer.

So we are very fortunate to be able to have to pump sitting here on the bank, I'm pretty excited about having them near 22, ok.

So from the high pressure fuel pump.

We of course, go to the fuel rail, right? And what happens with this guy with the fuel rail is pieces of metal embedded into the rail.

Obviously, this is a closed unit.

We can't really get inside of it in see any type of damage.

So we go ahead and replace that as well and that's when cases done little coming here and let's, just gonna cause problems down the line, correct? Okay? And then from the shore, real, we move, of course to the fuel injectors, right and is that the same issue where you could have metal pieces.

You can come in here.

And so you want to replace these early on.

We actually weren't replacing the injectors and almost, yeah, you know, I actually, go rock climbing.

And so it gives me phenomenal grip strength and obviously, huge muscles where you can see what I had to do to this one to get it separated.

So if you can impress your teeth a little bit I did I.

Did yeah, we replace the injectors as well for the same reason, all of these parts you really need to think of in this way they may not be damaged today.

But the longevity of the part may be significantly reduced it to be fine for another 10,000 miles, right? Or you know, you could put it on the fragment sitting here and it's waiting to just destroyed and you're, waiting and waiting.

And finally, 10,000 miles later, it clogs it up.

And then you have other problems or its clubs open, which will make for somebody to have a really bad day loans wherever you are pumped eight hundred or so far through these high-pressure.


So it's, no joke, it's, not a joke it's.

Not a joke.

You shouldn't, put gasoline in your to give folks an idea, the catastrophic damage.

This really is if someone would have to pay for all of these parts you're, looking at about $1,000, repair $8,000.

And how much of that is parts, you know, it's it's about 4,000 and parts of 2,200 in labor, depending on the area of the country you're in the other thing.

You gotta remember is that when gasoline and diesel remix, there are special disposal processes that has to go through.

So that is actually super sounds like twenty-five, dollars a gallon to dispose of the team's.

All-Time curious obvious since I've, got four thousand dollars $1,000.

And generally this costs $1000.

Well, that's a lot of that is need fuel, expenses 25 bucks for a gallon.

What what happens when you have fourteen times 25 isn't 3,000 well, you know, I, don't match.


So it's about 800, you can do the math itself Jason, perhaps if we had a whiteboard or we could actually executed, you know, 4+1, I usually can do in my head.

But anyway, regardless to be $1,000 value.

You know, we can agree I think that is an incredibly expensive repair in these parts of actually come down a lot and it's, very simple thing to do to just put the rock.

I mean, it's, not necessarily Volkswagen tries to make it preventable, right? So that you don't put the wrong fuel in, but it's, very easy to put the wrong fuel in from a.

You know, it doesn't take a genius to figure it out, and you can very easily cost $1000.

And think of what happens if the truck killing at the station this fuels, the tank would have seen happen too.

So it can be any anywhere along the process can result in this viewing note in used to be this way.

The older diesel engines would actually run on gasoline around like crap, but they would run, and we would just pump pump pump gasoline output fuel filter in it and we'll be good to go.

But today, it's quite a bit of a repair.

So what you should take away from the video is that you should not put gasoline in your diesel car, which you probably knew beforehand, but we may or may not have known beforehand as the issuance subscribed to charles is channeled mechanic and I will, of course, have links all over the place that make it easy to do that one of the things that they might want to take away, but I'm, really well, you know, I work gloves cuz I was nervous about touching real parts, and we all have our strong points.

And we all have things like gray hair that kind of hold us back in my so guys watching.

And if you have any questions or comments below.


Putting Gasoline In A Diesel Car - What Happens? ›

This means the diesel fuel will prematurely ignite in the diesel engine, which can lead to engine damage. Gasoline contamination can also damage the fuel pump and mess up diesel injectors. This happens because of a drop in lubrication.

How do you fix a diesel engine with gas in it? ›

Empty the Tank

On older diesels, nine times out of 10 the process of draining the tank, flushing the lines and starting over with fresh diesel rectifies the situation. By older diesels, we mean engines that made use of lower injection pressure and looser tolerances—primarily those with pre-common-rail fuel systems.

How much gas is too much for a diesel engine? ›

As a safe amount some car manufacturers will say none though the industry generally accepts 7.5% or less of petrol in diesel is safe. When you work it out for your tank capacity you will soon realise it's not a lot of the wrong fuel before it's too much.

How much gasoline does it take to contaminate diesel? ›

However, a contact at the American Petroleum Institute [3] reported that on average, diesel fuel is contaminated with approximately 1 cup of gasoline per 4,000 gallons of diesel fuel; this level of contamination would not be significant.

Will regular gas ruin a diesel engine? ›

The error, which in most cases is unintentional, causes damage (from diesel pre-ignition) that goes beyond only an engine; it also can ruin a vehicle's fuel pump and injectors because, as a solvent, unleaded gas lacks the lubricity that diesel has.

How much does it cost to flush diesel out of car? ›

Diesel fuel in a gas tank

While engine damage is unlikely, you will need to get the tank drained, a service that may range from $500 to $1000, and pay for the cost of a tow.

Will 1 gallon of gas hurt a diesel? ›

Diesel fuel is also considered a lubricant, so if you use regular gas when you are not supposed to, it does not allow the fuel injector pump to be properly lubricated. Gasoline detonates earlier, so when it is wrongly added to a diesel vehicle, it can cause engine knocking, misfiring, and damage.

What are the symptoms of gas in a diesel engine? ›

Common issues associated with putting gas in a diesel engine include:
  • No Ignition. Gas requires a spark plug to ignite, but a diesel engine does not have spark plugs to ignite fuel. ...
  • No Lubrication. ...
  • Fuel System Issues. ...
  • Shockwaves. ...
  • Engine Failure.
Jun 19, 2020

What happens if you accidentally put unleaded in a diesel car? ›

Putting petrol in a diesel car can result in severe engine damage and should be rectified by a professional service as soon as possible. Adding petrol to diesel fuel creates a solvent that reduces lubrication and can cause critical damage to the fuel pump and associated fuel system.

What will destroy a diesel engine? ›

Thousands of diesel engines fail prematurely each year aided by the presences of glycol, fuel, soot and water in the engine oil.

How can you tell if diesel is contaminated with gasoline? ›

If you have a diesel vehicle and fill it with gasoline tainted fuel, you would notice explosion sounds from the engine and see whiteish gray smoke coming out of the car. Gasoline contamination can damage turbochargers, fuel pumps, and dirty diesel injectors.

Will gas evaporate out of diesel fuel? ›

Diesel fuel is most often a light, refined petroleum product. Small diesel spills will usually evaporate and disperse within a day or less.

Will a small amount of petrol damage a diesel engine? ›

What happens if you mix petrol and diesel? Just 1% petrol contamination in a diesel tank will lower the diesel's flash point by 18 °C, meaning diesel can prematurely ignite in the engine, which can result in significant engine damage.

Does gas float on top of diesel? ›

None of them will float on top of one or the other. Since diesel weigh more than gasoline , why won't it float on top of diesel , water weigh more than the fuel, If you add water to your gasoline or diesel tank , will it mix or go to the bottom of the tank ? Water and petroleum are not soluable by each other.

Is putting gas in a diesel truck covered by insurance? ›

Unfortunately, your car insurance may not cover losses due to misfuelling. Most insurance companies do not include coverage for this type of engine damage or the costs of draining your fuel tank due to a mistake. However, it might be included if you have a high-coverage policy or mechanical breakdown insurance.

Does insurance cover wrong fuel? ›

Insurance companies do not usually cover you if you put the wrong type of fuel in your vehicle. If you further damage your car by trying to drain the fuel yourself, or by driving the car when the wrong type of fuel has been put in your car, you are likely to be out of pocket for all of these costs as well.

What happens if I accidentally put the wrong gas in my car? ›

If you put the wrong fuel in your car, get it towed to a mechanic where they will drain it out and make sure it's running smoothly.

How do you test for gas in a diesel? ›

Test your diesel fuel for contamination. Simply dip a 4-in-1 test swab in your fuel tank and check the test chart to determine fuel quality and the presence of contamination (water, rust, sludge/asphaltenes).

How long will a gallon of diesel burn? ›

On its own, most diesel fuel is designed to last no more than 28 days. This is because the demand for low-sulfur diesel has made most commercially available fuel less resistant to bacteria growth and, as a result, more prone to contamination.

What color is diesel fuel? ›

On-road diesel is clear or slightly green. Refineries place a green dye into diesel fuel which is obvious if fuel is freshly dispensed into a bottle to observe its color. As fuel ages this dye fades to yellow or darker colors.

What are the symptoms of diesel fuel toxicity? ›

Breathing in diesel exhaust can cause lung irritation and/or an allergic reaction causing asthma (wheezing and difficult breathing), or making pre-existing asthma worse. Other symptoms may include feeling lightheaded, headache, or nausea. Long term exposure may lead to serious health effects.

Why does my diesel engine smell like gas? ›

A Gasoline Smell in the Exhaust

If the exhaust coming from your vehicle smells like gasoline, it's often due to an overly rich air/fuel ratio. This means that either too much fuel or too little air is getting into your vehicle's combustion chambers.

How much does it cost to fix petrol in a diesel car? ›

For a fuel disposal and little repairs, it can approximately cost $200 – $300 to fix the issue. If the engine was severely damaged after the fuel flowed through the system while driving the costs to fix the issue can be as much as $9000.

How long will a diesel engine run on petrol? ›

Depends on how much diesel into how much petrol. if it is a full tank of diesel the car might manage a few 10's of meters, once the fuel lines/filter are empty of petrol the engine will simply stop. Spark ignition does not ignite diesel. A few litres and the car may well run for several miles before failing to run.

Can a diesel engine be fixed? ›

Diesel engines require regular maintenance and attention, as minor issues can quickly lead to costly damages. Luckily, an engine overhaul is a good way to correct numerous problems — and it costs a fraction of the price of a replacement.

Is there a drain plug on the fuel tank? ›

This plug is simply a small bolt screwed directly into the tank. Opening it simply creates a hole for gas to drain out. You usually need a spanner or socket wrench to remove it. However, not all vehicles will have this drain plug.

What will ruin a diesel? ›

Water causes damage to both fuel tanks and engine parts. Rust and corrosion in the tank create hard particulate that is passed along in the fuel, causing engine wear.

What will ruin a diesel engine? ›

Thousands of diesel engines fail prematurely each year aided by the presences of glycol, fuel, soot and water in the engine oil.

How do you know if your diesel engine is blown? ›

White smoke: One of the most obvious signs of excessive blow-by is white smoke coming from the oil-fill tube or a valve cover. Oil film: Another telltale sign is a layer of oil film around the tube, as blow-by causes unburned fuel to contaminate the oil and leak into the crankcase.

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