Does A Bad Gas Cap Cause Stalling

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Bad Fuel Gas will go stale in as few as 30 days, especially fuel mixed with ethanol as it is in many areas. Ethanol attracts moisture over time and the moisture will dilute the gas. Diluted gas may cause your engine to stall. Bad gasoline in your tank can cause problems in a car engine, like knocking and pinging, engine misfire, rough idling and stalling, according to AA1Car.com. The problems will typically involve how the car drives and its emissions.

We take gasoline for granted.

For most of us, it’s as simple as putting gas in, and thendriving away. These days, it’s very rare that you’ll get bad gas from a gasstation. In over 18 years as an auto mechanic, I’ve never seen someone’s enginedamaged by bad gas.

It just doesn’t happen as much as it used to.

But it does still happen.

Back in 2012, over 4.7 million gallons of gas were recalled from BP stations in Chicago, Northwest Indiana, and Milwaukee. The bad gas, in this case, was contaminated with polymer residue, which doesn’t burn in automotive engines and can cause damage to the engine.

Generally speaking, bad gas is usually the result of contaminationfrom your fuel tank or fuel line. It can be the result of your car sitting foran extended period of time, or from water making its way into the fuel tank.

By the time you’re finished reading this guide, you’ll be anexpert in diagnosing if your car actually has bad gas, as well as correctingthe problem if it becomes an issue.

You’ll learn everything you need to know – and probably somethings you don’t need to know.

What Causes Gas To Go Bad?

Gasoline doesn’t stay good forever. The countdown starts assoon as you expose gasoline to air. After around 30 days or so of sitting inyour fuel system, your gasoline starts to oxidize.

When gasoline oxidizes it can gunk up your fuel system by turninginto varnish which can coat your fuel system and engine. As gasoline degrades,it goes from clear in color to looking more like apple cider. This “apple cider”gasoline then begins to gum up your fuel system and your engine.

Even worse, today’s gasoline often contains ethanol. When thesedeposits form, the ethanol in them attracts water from the atmosphere (it’s hydrophilicfor all you chemistry nerds).

Generally speaking, old gas in your car isn’t the end of theworld if you’ve let it sit for only a couple of months, but if your car hasbeen sitting for 6 months or more, you can run into some problems and you mayneed to use something like Seafoam.

We’ll get into what exactly you need to do in a bit.

Age is the most common cause of bad gas, but it’s far fromthe only one.

Water can also get into your gas tank. This can be caused by a loose gas cap, or from condensation. It’s also possible that water can make it in from the pump itself – although this is getting more and more uncommon.

Besides age and water, you may also have contaminated gasfrom a cracked fuel line, or from flakes coming from your gas tank.

What Are The Symptoms Of Bad Gas In Your Car?

Bad gas is fuel that doesn’t combust as expected. With thatin mind, most of the symptoms are related to the car not running as expected.

Your car relies upon fuel being delivered to the combustionchamber and igniting optimally. When this doesn’t happen, the car oftenhesitates and suffers from a lack of performance. With that in mind, somesymptoms of bad gas to look out for include:

1: Difficulty Starting Your Car

If your car cranks but won’t start, it could mean that youhave bad gas. Contaminated gas doesn’t provide enough power to start theengine. However – if your engine doesn’t start, you shouldn’t automaticallyassume you have bad gas. Anything from bad spark plugs to a busted fuel pumpcan cause your engine not to start.

If you have a lot of bad gas in your tank, this can causeyour car not to start in some cases.

2: Sputtering Or Pinging Sounds When The Car IsIdling/Driving

Bad gas doesn’t combust evenly – which can cause your engineto sputter or ping. Listen to your car both at idle and while driving atmoderate speeds. These noises aren’t the smoking gun on their own, because theycan also be caused by a bad fuel filter.

3: Stalling While Driving

If your gas is contaminated with sediment or with water, it’spossible that your car may stall while you’re driving because the fuel is notcombusting correctly. This only happens in extreme cases, so more likely thannot, it’s not something you’ll have to worry about.

4: The “Check Engine” Light Coming On While Driving

Bad fuel can cause your car to run lean. If you have an OBD-II code reader, the code will almost always relate to your engine running lean.

5: Burning More Gas Than Usual

When you have bad gas, your engine will have to work harderthan normal to produce the same amount of power. This can show up as your car burningmore fuel than usual. On its own, this isn’t a smoking gun, but if you noticeit together with the other symptoms, pay attention.

Cause

6: Trouble Accelerating

If you have bad gas, it’s common for you to have troubleaccelerating or going up hills or other steep inclines because bad gas doesn’tburn correctly.

7: Speed Changes While Driving Without Pressing The Gas Pedal

Bad gas can also cause your car to abruptly change speedswhile driving. You may notice a sudden slow down, followed by a surge of speed.

What Are The Symptoms of Water In Your Gas Tank?

The symptoms of water in your gas tank depend on how much water gets into your gas tank. If there’s only a little bit of water, you might not notice it at all.

But if there’s a lot of water in the tank – you’ll definitelyknow.

The main thing to watch out for is hesitation when you tryto accelerate. When there’s water in your gas, your engine won’t be able toperform up to standard. The more water in your gas, the worse this will get.

The other symptoms I’ve already covered above.

So, Can Bad Gas Damage Your Car?

The answer is yes – but for it to get to that point you need to really let things go for a long time. Bad gas can form deposits that can cause issues in your engine. Again, this is very rare and probably won’t happen, but it’s good to know.

However, if you get bad gas from a gas station, you could be in for quite the repair bill. Although I’ve never seen the damage personally, I have seen reports ranging from $1,000 to $2,500+.

How To Get Reimbursed For Bad Gas

As I previously mentioned, most bad gas is probably not thekind you’ll be able to be reimbursed for. For example, if your gas goes badbecause it’s old you’re not going to get reimbursement.

However, if you put gas in your car and it almost immediatelystarts coughing and sputtering, then you may be on to something.

To prevent yourself from getting the shaft, you need to makesure you get a receipt. If you can prove you got bad gas from a gas station,then you’ll be able to get reimbursement.

More likely than not, you’ll be paid through the gas station’sinsurance policy. You may also want to call your state’s consumer protectionagency to report that you got bad gas to prevent others from getting burned asyou did.

With that being said – how can you be sure if you have badgasoline or not? You test for it.

How to Test For Bad Gasoline

The first thing you should do is ask yourself if it’s possible that your gasoline was contaminated due to your own error. Whether that was through letting your car sit, or through a loose gas cap, or something similar.

If you can rule these out, then it’s somewhat difficult to testthe gasoline without special tools.

A fuel test procedure and kit (without sending out to a lab)involves 3 steps.

  1. The first involves lowering a probe to the bottom of the tank with a paste that changes color if it touches moisture. The probe almost resembles a bicycle cable in a clear sheathe. This requires the probe and the color-changing paste.
  2. The second involves retrieving a sample of the gasoline. Place the gasoline in a graduated cylinder. Add some amount of windshield washer fluid. Cork the sample and shake the tube. Wait until it settles. Compare how much gasoline you put into how much is left after everything settles. This shows how much alcohol is in the fuel. It should be no more than 10%. All this test needs is a graduated cylinder that can survive gasoline. This is the easiest thing to acquire.
  3. The third involves retrieving a sample of the gasoline. This test measures the volatility of the gas known as Ried Vapor Pressure and requires another special testing tool. Chill the gasoline and tool on ice for 30 min. Pour the fuel into the tool and close it. Place the tool into hot water for 10 min and measure the water temperature. Read the pressure from the gauge on the tool. Compare the pressure and temperature to a table that comes with the tool.

How To Get Water Out Of Gas

If you have water in your gas, the first step is to figureout how much water you have in your tank. If your car is still drivable,chances are you don’t have too much water in your gas tank.

However, if you’re having serious performance issues – then you’llneed to go another route.

In this case, you have a few options.

They include using a product like Heet or by doing it yourself with dry isopropanol alcohol.

Considering Heet is about $3 on Amazon, it’s usually theeasiest option.

If Heet or isopropanol alcohol doesn’t fix the problem – thenyou’ll need to siphon the gas out of your tank.

Get a fuel siphon, and then feed the tube into your gas tank and get pumping. Pump the siphoned fuel into a clear container so you can inspect it, and then refill your gas tank with good dry fuel.

How To Fix Bad Gas

Fixing bad gas, on the other hand, is much simpler. If you have true bad gas – not old gas, or waterlogged gas, then you’ll need to siphon the gas out of your tank and pump new gas in.

Don’t mess around with this, because bad gas can causedamage when it does happen, even if it only happens rarely.

Diesel tractors are usually much more reliable than gasoline tractors. They are known for their durability and the fact that you can store them for long periods of time without affecting their start-up mechanisms. That’s why it’s so frustrating when your diesel tractor keeps stalling.

Diesel engines need three things to run; fuel, air, and compression. If your engine is not getting one of these three things in proper amounts, it can sputter and stall.

The 7 common causes of a diesel tractor stalling include:

  • A fuel delivery issue
  • Clogged or dirty filters
  • Fuel contamination
  • Blocked or damaged hoses
  • Incorrect parts
  • Broken fuel cap
  • Fuel shut off solenoid malfunction

Let’s break down each of these points of failure and see if we can identify what’s causing the issue and get you back to work.

Make Sure The Fuel Cap Vent Is Not Clogged

The most common cause of a diesel tractor stalling is a clogged or damaged fuel cap vent.

Diesel fuel caps have vents to prevent a vacuum effect. If the vent is clogged, the engine won’t be able to properly pressurize, and the engine will be stifled and die (source).

To check if this is the cause of your problem, it’s often recommended that you remove the fuel cap, start the engine, then run it for an hour or so.

If the tractor runs without issue, then the problem is the fuel cap. Either try cleaning the cap, then putting it back, or order a new one.

But I don’t like that troubleshooting approach because you can introduce impurities into the tank if it isn’t capped. I generally recommend removing the cap and giving the vent a good cleaning then seeing if that solves the issue.

Determine if You Have a Fuel Delivery Issue

Another common reason for diesel tractors to stall is a fuel delivery issue. Assuming you have enough diesel fuel in the tank, check the engine hoses for blockages.

Then, check your fuel filter. Often, the fuel filter can get clogged on the intake side of the filter. One way to check this is to remove the fuel filter (bypassing it) and see if the tractor runs. If so, the filter will need to be replaced.

Examine Your Filters

Air, pressure, and fuel are the crucial components of a diesel engine. Filters affect all three of these mechanisms.

Can A Bad Gas Cap Cause My Car To Stall

If the fuel filter is clogged, the fuel will not flow through it and cause the engine to lose power.

If the air filters are clogged, like in the fuel cap, the engine will not be able to pressurize, and again the tractor will stall.

There are other air filters in the engine, and surprisingly often these are installed backward. This causes the filter to block air intake instead of clearing it.

Fuel Contamination

Another potential cause of a diesel tractor stalling is that your fuel has been contaminated (source).

Some of the most common types of contamination of diesel fuel are:

  • Water. Water is very damaging to your diesel engine. If your diesel gets contaminated with water, it can cause the iron and steel components to rust. This rust can in turn clog your fuel filter.
  • Inorganic debris. Particles of sand, dust, and rust may contaminate your diesel fuel. These can clog the filters in your engine, and prevent it from running properly.
  • Organic debris. Even the smallest amount of water introduces to your diesel fuel will, over time, give life to microbial bacteria. Bacteria, molds, and fungi can grow in your stored diesel fuel.

Look for Blocked or Damaged Hoses

The hoses on your tractor are vital for the transferring of fuel from the fuel tank to the engine. To check these hoses, remove the fuel lines from the tractor engine, and hold them up to the light. You should be able to see any large obstructions.

There are two main lines to check:

  1. The line between the tank and the fuel filter.
  2. The line between the fuel filter to the injector pump.

If you’re sure that the hoses are clear, and punctured or cracked, you may still have an issue with your fuel lines.

The fuel is delivered to the engine under high pressure, if there is any amount of air in these lines, the engine won’t run. To fix this, the fuel lines must be bled to remove any air pockets from the tubes.

This YouTube video offers some practice, best practices for preventing fuel issues in a tractor:

Ensure Your Tractor Has All of the Correct Parts

It is a surprisingly common issue; your tractor won’t start because somewhere in the machine, the wrong part is in place. For instance, your fuel cap may actually be a gas cap and doesn’t have the proper vents to pressurize the engine. You may have the wrong sized filters or hoses for your engine.

Perhaps one of the parts is installed incorrectly, like the air filter being installed backwards. Or perhaps your mechanic over tightened a screw while installing a part, and stripped the thread, causing the piece to loosen over time.

Examine the parts of the tractor that you know, and ensure that they are the correct ones and properly installed.

Electric Fuel Shut Off Solenoid Malfunction

Another potential issue that you are facing with your diesel tractor is a failed part, such as the fuel shut off solenoid. This part is required to open and close to direct the flow of fuel to the engine.

The solenoid may malfunction and become stuck in the closed position. This won’t allow fuel to get to the engine, causing stalling. To fix this, you will have to replace the solenoid altogether.

While the solenoid is one potential part that can malfunction, it’s true that your issue with your diesel engine could be a broken mechanical part. You may have encountered a blown gasket, cracked seals, or seized engine parts.

These are often best dealt with by a professional.

eManualOnline provides descriptive, affordable and convenient service and repair manuals for cars, trucks, tractors, motorcycles, and more. Download one today. (link to eManual Online).

Can A Bad Gas Cap Cause A Car To Stall

When to Call a Professional

Can A Bad Gas Cap Make A Car Stall

Speaking of professionals, it’s important to know when to call one. The best rule of thumb is “when in doubt, send it out”. If you are at all unsure about your skills as an at-home mechanic or are worried you will damage the machine further, sending your diesel tractor to a professional mechanic shop is the best choice to fix it.

Summary

Does A Bad Gas Cap Cause Stallings

In summary, if your diesel tractor keeps stalling, there are a few main issues that could be causing it.

Can A Bad Gas Cap Cause Your Car To Stall

The most common of these is that your fuel tank cap is clogged or damaged. To test this is simple: try running the engine for a while with the cap off. If the engine works without stalling, simply replace the cap and move on!