5 Symptoms of Sugar in Your Gas Tank (and How to Fix)

The theory is that if you put enough sugar into a gas tank (please don’t do this!), it will thicken the liquid to the point where it cannot be used. The altered state of the fuel then prevents the vehicle from operating.

But will adding sugar to someone’s gas tank actually disable their vehicle or is it just a silly myth? Whatever the answer is, sugar in gas tank symptoms are not as straightforward as one might think.

What Does Sugar in a Gas Tank Really Do?

Sugar does not dissolve in gasoline as it does in water. It settles to the bottom of the gas tank instead. The granules then move through the fuel transmission lines based on the flow of the gasoline.

Most vehicles have a sufficient fuel filter which prevents sugar from making its way to the engine. With enough sugar in the gas tank, you could clog that filter to reduce the effectiveness of the system, but it would take several pounds to make this theoretically possible.

If you suspect there is sugar in your fuel, then here are the symptoms to keep an eye out for.

Top 5 Signs You May Have Sugar in Your Gas Tank

1) Power Surges During Acceleration

car won't accelerate

When there is sugar in a car’s gas tank, the granules begin to clog the fuel intake lines. This obstruction prevents the standard level of fuel from being consumed.

You’ll get surges of power when enough fuel does arrive for combustion, then lulls in acceleration when the clogs reduce the flow of gasoline.

2) Engine Stalls

engine stall

If the fuel transmission lines become clogged entirely, then your car may stall when you attempt to accelerate. You may see the car struggle while idling too, with the possibility of a stall there as well.

The vehicle may lurch when moving forward or reverse, immediately stalling again after restart.

3) Car Doesn’t Start

Most sugar in the gas tank symptoms will lead to this result. Severe clogs result in a complete blockage of fuel access. You’ll find that the engine does not want to start at all. It may turn over for you when turning the ignition, but then nothing else will happen.

Continued attempts to start an engine in this condition may wear out the battery, which would create a clicking sound when starting. Premature wear of the starter is possible too, as well as damage to the alternator, engine, or other components under the hood.

4) Poor Vehicle Performance

If you don’t notice any of the above issues with the sugar in gas tank symptoms, then this issue may present itself during vehicular operation. Some sugar granules do make their way to the engine over time because of the fuel flow.

The heat the sugar encounters around the valves, pistons, and cylinders create a caramelized effect that may coat the engine components. When this happens, you may notice the engine under performs when you accelerate.

5) Fuel Pump Failure

bad fuel pump

If the fuel filter is located after your fuel pump, then the sugar may caramelize on your fuel pump mechanisms. Enough buildup over time would cause the fuel pump to simply stop working, which would prevent the car from starting.

You may hear the pump begin to whine, squeal, or make other unusual noises when a thick coating begins forming.

How to Fix a Sugar in a Gas Tank Problem

If you want to know how to remove sugar from a gas tank to restore operations, then you must manually clean the gas tank and any affected components. You or your mechanic will need to remove the fuel tank from the vehicle, disconnecting it from the fuel pump and lines.

Related: Symptoms of Water In Your Gas Tank

Try to remove as much fuel as possible before starting this job. It will make the tank lighter, and you’ll have less risk of fume exposure.

Place the fuel tank on a level floor. Siphon away any remaining fuel from the container. Then take a pressurized hose to clean the interior of the tank. Empty the water, then take a vacuum, like a Shop-Vac or similar type, to remove any sugar, rust, or debris remaining in the tank.

The final step in knowing how to clean sugar from a gas tank is to wipe down the interior completely. Then allow it to dry for at least one hour to give lingering moisture an opportunity to evaporate.

Sugar in gas tank symptoms do not include the engine blowing up, despite rumors and stories which say otherwise. You may experience difficulties in starting the engine or reduced performance of the car.

When you know how to fix a “sugar in a gas tank” issue to restore its functionality, you will discover this mechanical issue creates minimal downtime.


31 thoughts on “5 Symptoms of Sugar in Your Gas Tank (and How to Fix)”

  1. Sugar does not dissolve in gas. Most of the times if you do get it in your tank. A tank flush and filter change will cure any problems. As most times a clogged filter is what causes your issues. Now if you have no filter for some reason other things can get clogged up.

  2. I just bought a 05 f150. I put bad gas in it that had been standing for quite some time. So it started running rough at times and I figured if I put super unleaded in the tank the rough running would go away, it didn’t. So now I decided to run the fuel out of the tank until it died. I have since put octane boosts and super in the tank and still I have this problem of rough running at all speeds. Surely nobody got me! I put a lock on it just days after I bought it, paid 8900.00 for this truck, it ran great, there have only been a few days of waiting for the gas cap lock to arrive that I could have been hit. My engine light is on and it is diagnosed with emissions failure. Did I get hit. Is this why my other car is screwed up too. Do I have sugar in my tank? and does the other car tick for the same reason? I paid 7000.00 for it last year. Can I expect a ticking from my truck soon too? A couple of years ago I had an 07 Avalanche, start ticking, and I paid 10500.00 for it. Lost my butt on repairs, over 4000.00 dollars. I don’t have any enemies that I know of. My ex is in WV, and as far as I know we’re good. There is the town idiot that might be disturbed enough to do this sort of thing. Is sugar the culprit? I mean the tick before the death of the motor?

  3. I had a friend whose girlfriend had sugar put in her gas tank by her ex. He hid in my apartment because he was scared of the ex and even bought a stun gun. My parking place matched my apartment number and since he hid in my apartment when he thought he saw the guy instead of his own nearby, think the guy might have scratched up my hood when noticed scratches? I was driving from Lincoln, Nebraska to Omaha on I 80 when the car died and dashboard lights went off while at highway speed. Coasted to stop but could not start car. Always wondered if sugar could have caused engine stall and dash boards lights to go off while driving.

  4. This article says your engine won’t blow up but I have to disagree! My ex put sugar in my gas tank 2 years ago and no mechanic believed me to check that so the sugar stayed in there for 2 years…my car blew out black smoke out from the exhaust, struggled up small hills, drove slow and the engine light never turned off. My car died and then finally my last mechanic diagnosed it with stuff put in the tank. The engine was wreaked…had new engine put in, new Cadillac converters, new fuel pump, new fuel filters and all these other new parts. Has cost huge amount of money to fix…if I had known this cost before hand i would have pushed it off a cliff and brought a new car. Just saying my story because this article says it won’t blow up a engine and it blew up my car engine so this article needs to be edited and corrected to give correct info. After all this the engine light has turned back on…I’m going to suggest to my mechanic to install a new gas tank next

    • Typically when people talk about an engine blowing up, they mean they’re sending a connecting rod to the moon. This is a catastrophic failure, not just poor performance. Sugar alone probably won’t cause your engine to blow up.

    • Sugar will not dissolve in gas. It sits at the bottom of tank. Plus the filter would catch any grains before it made it too the injectors. It definitely would not hurt the Catalytic (not Cadillac that’s a car) converters. Fuel pump maybe if it was in there long enough. Filter definitely will clog it up. If you did have sugar in the tank then the reason the car struggled so bad it had a clogged filter. Running it that way for two years. Is why it blew up if it indeed did blow up. You were running the car super lean which will cause lose of power, hard start ups, burnt exhaust vales causing smoke and eventually blow an engine up. Sound familiar?

    • You probably still have the old gas tank, fuel pump, lines and maybe even the filter. Be consoled that you have something good your ex wants and can’t have.

  5. Where do I find step by steps to basically dismantle my ’99? Not sure Chilton’s goes that far in depth; I plan to clean the entire fuel feed process

    • I don’t think there’s anything you can add that will really fix the problem. You’ll probably have to drain the fuel tank, then clean the tank and any other part of the fuel system that’s been affected.

      • The filler pipe can be removed most have a rubber hose between the neck and tank you can pull it with drooping the tank

  6. Hello, my car has a hard time starting after I put gas in it. It has a lot of the signs of sugar in the tank, but the coolant is also boiling. Could that be from the same thing?

    • Perhaps it’s just some debris that blew in around the fuel door. The gas tank cap is airtight, but the door covering it probably isn’t.

      • Thanks Sean…even if its debris can it slow gas when I’m pumping gas into tank because I couldn’t put gas it’s going really slow so I let it alone …

      • I’m not exactly sure what you’re looking at so I don’t know. If it’s slow to pump gas there could be something preventing the air in the tank from exiting. This would stop the pump frequently and make it very slow to fill up.

  7. Currently having all these problems that were brought on in a matter of 2 days my car has never in the 2 years that I’ve had It have all these problems until now, and to no surprise I have someone who despises me enough to do it. Thankfully I get it looked at tmw

    • A sweet like smell is usually when you have a coolant leak. If your coolant level is low or your car is overheating, an internal leak may be the culprit and you should drive the car until it’s correctly diagnosed. Could be a blown head gasket.

    • The sweet smell is similar to molasses being cooked. Such as molasses in cookies, pies, barbecue and it thickens and is turning to a tasty crust.

  8. pS. I just kept driving it because the mis always went away after exactly 3 miles on the freeway and it never came back until the engine cooled completely usually overnight.just got much worse and will barely start and smoke when it does start. Randomly it will idel well with no smoke but when it doesn’t it’s a smoker.

  9. My car and I have suffered all symptoms for a year now. And yes it almost blew up, major backfire once while starting, blew a new muffle wide open and blew vacuum line off the egr hopefully not head gasket. Dozens of water remover bottles because it seemed to make the problem go away but it never did. One minute, it’s fine no smoke, then missing and smoke( valve& rings are probably coated. 1993 Sidekick


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