Nissan Sentra - Water in the Gas Tank!

My initial post to the forum might turn out to be a long one.

About 6 weeks ago, my wife’s Nissan Sentra stalled on her while she was driving to work. We had the vehicle towed to a Nissan dealership. The problem turned out to be water in the gas tank.

Well, the day before I washed the car. The car wasn’t driven any more that day. The next day, the car broke down on the interstate with my wife.

“Water in the tank”, we were told. "Okay, but how did the water get there?’, was my question.

I was advised that I must have “bought bad gas”. This was troubing, since I have bought gasoline from the same neighborhood station for almost 20 years. So, I told the dealer he was selling bad gas. Suffice to say, he did not accept this news in the spirit that I intended.

The service fee at the Nissan dealership came to about $300.00. Add another $125.00 for towing.

A couple of weeks goes by, and we experienced a torrential rain. The next morning, the car shook, caughed and sputtered before dying again. We towed the car back to the same Nissan dealership.

“You have water in your gas”, we were told.

“Again?”, I asked. “How?”

This dealer again told me that I had bought bad gas.

“You mean to tell me that I managed to find another station in town that sells watered-down gas?”, I asked. The service manager then backed off a bit. “Then maybe some kids in your neighborhood put water in your tank”, she offered.

Pretty much the same repair and towing charges from the first incident applied here. all in all, another $400-$500repair. In two weeks time!

I called my local police department. The officer just laughed out loud. “Not in your neighborhood”, he said. I’ll point out that we live in a Mayberry-esqe suburb. The officer said that there had been absolutely no other complaints by neighbors of water in their gas.

A couple of weeks later, we had another torrential rain. You guessed it! Five minutes into her morning drive, the car sputtered and died on my wife.

Suspecting that the first Nissan service department just might be incompetent, we had the car towed to another Nissan dealership.

I called the service manager to check on the car. “You have water in your gas tank”, I was told.

This brought the number of water-in-the-tank episodes to three.

I told the new service manager of my previous two problems in recent weeks. He assured me that “pressure test” was done, and no leaks could be found - the car had no defect.

Charges and towing came to another $400-$500.

When I asked the dealer how in the world water could possibly keep getting into the tank he said, “if gasoline sits long enough it will turn to water”.

I pointed out that my 1990 Isuzu Trooper that I was driving (wife has since commandered my newer vehicle) had been sitting in my driveway for 9 months and that I was driving with the gas that had been in its tank the entire time. “It takes longer than a few days for gas to turn to water”, I tried to explain.

A couple of weeks go by and we experience a nother heavy rain. As expected by now, the car died on my wife’s drive to work.

We towed the car back to the second Nissan service department. Water in the tank, again!

This service manager maintained that there was nothing wrong with the vehicle. He suggested that vandals were the culprit.

In addition to living in a peaceful, crime free neighborhood, my wife parks her car next to my neighbors fence. Inside this fence lives a playful dog who barks up a storm (though fortunately, not the rainy kind) whenever anybody passes in fron of our house. A free watch dog service!

Anyway, this repair cost another similar amount of money.

At this point my frustration with Nisssan is getting pretty high.

My wife and I began to make calls to Nissan - trying to find someone at the corporate level sympathetic to our problem.

We finally got a person to return our calls. To make this very long story a little shorter - this representative had the personality of a lobotomized zombie.

I discussed this matter with this rep at length, citing all 4 times that the car had choked out as a result of water in the tank. His only reply was a constant reiteration of, “there is no defect in your car. We have performed pressure tests on your tank and there is no deffect…”.

This past Sunday, I drove the car to the grocery store. It performed fine.

But as I got home, the heavens opened up for a 3 hour, driving rain.

I just sat and stared out the window ant the car. “You know the car is going to die again”, I told my wife.

After the rain had stopped, I got in the car to drive it. Three minutes into the drive, the car died again. Water in the tank.

So, I called everybody with Nissan that I could reach by phone. I requested to speak with Nissan CEO Carlos Ghosn, but was told by several of the Nissan reprasentatives that he, “is not allowed to be spoken with”.

This week I have spoken with no fewer than three Nissan representatives. They all just repeated their mantra - “there is no defect in your car …”.

To brifly iterate:

The first incident came after a car wash.

The second incident followed torrential rain.

The second incident followed another torrential rain.

The third incident came after another heavy rain.

The third incident followed heavy rain.

And now, the car sits on the side of the road with water in the gas - following another torrential rain.

This is our second Nissan. We felt that for the money, Nissan was the best buy out there. Sadly, we did not take the entire car company into account.

So my question to you Car Talk fans is - is there any other way (sans vandalism and stations selling watered down gas) that water could enter our Nissan Sentra’s gas tank?

Thank you for any light you can shine on this problem!


Birmingham, AL

Stations do not sell watered down gas and since you went to a dealership 3 times one would think they would have discovered how water entered your tank other than “vandalism”…no way water from rain can enter a fuel system that is intact. Perhaps there is a hole in the tank/filler pipe that lets in water after/during a storm…how could the dealership miss that???

Thanks for your response!

Yes, this is something that I asked about specifically. Not only that, through all of these episodes, they never even changed the gas cap - something else that I requested!

Could the cap itself be a suspect?

if your gas cap didn’t fit tight your check engine light would come on.

I agree with mshugna that there is likely to be a hole in either the tank itself or the filler neck, and that this hole is admitting water from the car wash and from rain storms.

You neglected to tell us the model year and the odometer mileage of this Sentra, so we have no way of knowing whether this car is still under warranty or not. If it is not under warranty, there is no reason to take it to the dealership unless you want to be charged much higher labor rates than what you would encounter at an independent mechanic’s shop. And, for those high labor rates, it would appear that you are not getting very competent mechanics.

Personally, I find it hard to believe that a pressure test was done on the gas tank. If it had been done, it likely would have shown that either the tank, or the filler neck, or the gas cap is defective. My theory is that there is a hole in an area of the tank or the filler neck that is not visible when the car is on a lift, and most likely the dealer’s mechanics are doing only a visual inspection, rather than a pressure test of the tank.

Seek a well-reputed independent mechanic in your area, and he should be able to solve this mystery at a more reasonable cost.

The next time you take it to them to get the water out. Insist that that spray water all over the outside of the car with a hose for a few minutes. Then have them check for more water in the tank.

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You keep going back to the same dealership and they keep blaming “water in the tank”. That statement is a commonly used excuse for those who want to take your money without actually doing any work.

In order for enough water to get into your tank from a downpour to affect your car, you’d need to leave the gas cap off and stick a huge (and I mean HUGE, like 6 feet across) funnel in the fill hole. And it would have to pour for an hour.

There are, however, numerous things in your car that could be getting wet in a downpour and causing your symptoms. And they’re all electrical in some form or other. Most are high voltage ignition components.

What year is this car?
How many miles?
How has the maintenance been kept up?
When was the last time the ignition components were changed (tuneup)?

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As usual, mountainbike has raised a very good point.

Without seeing the evidence yourself, there is a very real possibility that the dealership never found water in the gas tank. “Bad gas” is indeed the fallback diagnosis of many a bad mechanic or a dishonest/incompetent shop.

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This is a puzzler, for sure, made worse by a lack of information. Year, mileage, transmission type, maintenance history, etc, would be very helpful.

Here’s a question: Have you ever had any problems driving the car WHILE IT’S RAINING? Surely you must drive the car through rain now and then. Does the engine quit? You only told us the engine quits after the car is exposed to water while stationary.

If there were a hole somewhere, as others have speculated, wouldn’t the water get in the tank while you’re driving the car? The gas tank is under the car, so it’s not really exposed to water from washing the car or from rainfall. If there’s a hole water would get in while driving, not just when the car is sitting still, and if there were a hole you’d smell gasoline. You haven’t said you smell gas, so I don’t think there’s a hole.

It takes more than a little bit of water to make the engine stop running. Small amounts of water in the gas tank are common. You’d have to have a layer of water in the bottom of the tank, I think, to stall the engine, and that’s a lot of water to leak in through a small hole. How much water do they remove from the tank at the Nissan dealer? That would be nice to know, too.

The biggest problem you’ll encounter trying to fix this is getting a mechanic to take you seriously. Do you know any independent mechanics? The Nissan dealers aren’t going to be much help. They’re just going to do the same thing over and over. If you had an independent who was really willing to dig in and test everything you might come up with an answer. Or not. This is a very strange one.

Now, what about driving in the rain?

Thanks to all for the replies!

The car in question is a 2003 Nissan Sentra with only 35,000 miles! This is the proverbial, “car drivin by the little lady to church on Sundays”.

The amount of water found has been quite a lot. The first dealer told us at least a quart!

Yes, we’ve driven the car in the rain, but not in TORRENTIAL rain. The vehicle seems to have withstood light rains without the problem occuring. It has been after these heavy, heavy rains.

My next move is going to be to contract a local, reputable repair shop. The only reason that I had the car towed to the dealership is that I figured that it was THEIR car - they should be able to fix it.

What bothers me most is that fact that it looks like I’ll just have to get a new vehicle. I will point out that our Sentra runs like a sewing machine when it’s not broken down because of water in the gas. With only 35,000 miles (we are the original owners) - it just seems unreasonable that this car seemingly cannot be repaired.

I don not know much about cars (especially later models), but I have imagined that this leak or gap must be occuring somewhere between the nozzle hole and the tank - the section of pipe going to the tank seems to be a logical place to check.

Let me also point out that I do not smell gasoline while driving the car.

This pressure test that Nissan keeps talking about - this seems to be based on applying pressure from inside the tank. Could a test like this actually “seal” a leak or fissure from the inside? I imagine the pressure forcing the tank material upwards until it creates an artificial and non=lasting “seal”.

Until this problem is fixed, I just cannot sell this car to another party. My mama just raised me better than that!

Thanks again for all your answers! The more-the better!


Where is the filler cap?? Inside a little compartment in the fender?? This compartment will have a water drain to prevent it from filling up and possibly allowing water to enter the filler neck…Is this drain working? Inspect this entire area closely. If that checks out, then the entire fuel system, the filler neck and tank will have to be removed and inspected for leaks. You have already paid enough money to have had this done twice over…There is an access port in the top of the tank. It’s about 4" in diameter and is sealed with an “O” ring. That’s the next likely place for a leak.

Cover the gas cap with plastic wrap and a rubber band … see if that stops the rain.

I am also stumped about 2003 Nissan Sentra “water in gas”, It should have a system to check for pressure in the gas system, or kick on the engine light. So let’s think how water on the car accounts for water in the tank without setting off the cel. First check would be a pressure test on the fuel system, if it fails the source of the failure could be the source of the water. If it passes the pressure test then something is sucking water in where it should suck in air. Where is the air equalization intake for the gas tank on this car and I think there is the problem.

To the concise reply, wherever air is supposed to come from for displaced gasoline it could be putting water in the tank instead of air. find the source and have it checked.

Any shop that gives you a “water in the gas” diagnosis should be fully prepared to back it up with a contaminated sample of at least one quart.
So, has anyone shown you an actual sample of this bad gas?

Water always settles in the bottom of the tank. This means that if your car was vandalized or you acquired watered gas from a gas station the symptoms would appear quickly because the water would be the first thing the fuel pump would pick up from the bottom of the tank.

Another possibility here could be moisture laden secondary ignition components and the gas is erroneously getting the blame.
Water splash from the front wheels or moisture attracted by engine heat can dampen the ignition components and cause an engine to stall, fail to start, or run poorly. Just a possibility for consideration anyway.

(Bad gas can certainly occur but it’s not near as big a problem as diagnosed and perceived to be by many car owners. It’s more of a whipping boy than anything else and I agree with Mountainbike.)

I was going to suggest selling the car, but you don’t seem inclined to do that.

Maybe you should reconsider your position.

If this were my vehicle, I’d sell it.

Both dealerships did provide samples (32 oz soda bottles) of the gas/water mixture. That water is in the gas tank - I do not contest. It’s just how it got there that puzzles me.

This whole episode has driven me half-way mad. I am litterally losing sleep, having … awful ideas about what I’d do if I actually caught someone tampering with the car - but then I remind myself that that is not even a possibility. While the car is parked, it is locked. A vandal couldn’t access the nozzle without prying the door open, which would leave jimmy-marks as eveidence. I just don’t believe this is happening.

My own reasoning leads me to suspect the gas cap, or some other component in the chain before the tank.

I am told that the tank is pressurized and that it is impossible for water to enter the tank. Are there any moving parts that could have failed? I am thinking of the little round “door” located just inside the nozzle hole (the one that gets pushed open by the gas pump nozzle). This, or the fuel neck (I don’t even know what that is - it’s listed in the Nissan parts catalog).

Y’all are providing some great advice and feedback!

I’m going to tow the car to the independant garage this morning. I will report back later with any findings or results.

Selling this like-new car because of an unresolvable problem just seems like a rotten way to go. Again, I really hate the idea of unloading a problem onto an unsuspecting driver - just not my way.

Thanks again to all!


I too am puzzled as to how a quart of water can repeatedly get in the tank.

By the way, the tank runs with a slight vacuum rather than being pressurized. The Evaporative Emissions System ensures this in order to prevent gasoline fumes from escaping into the atmosphere.

There’s got to be some missing piece to this puzzle. I just can’t think of what it might be.

At this point here are the possibilities as I see it.
The tank has not been dropped and completely drained of all fuel and contamination.

Car wash or rain water is draining down and entering around a faulty seal at the fuel pump, filler tube, or a crack in the tank itself. Again, assumed this was checked with the tank out.

You have a comedian in the neighborhood who holds a grudge against you, but if the filler door can only be opened from inside the car and the doors are locked this would not apply.

The tank is not really pressured up and it is possible for water to seep inside the tank if there is a defect. Just to clarify though; the fuel tank has actually been dropped out of the car and inspected and this is not a matter of simply draining the gas out with the tank remaining in place?

Yesterday evening (7/16) you asked “Could a test like this actually “seal” a leak or fissure from the inside?”

In general, absoulutely. In my involvement with underwater devices we would often test the seals by pressurizing internally – but we knew that there was a risk that a seal so-tested could leak under external pressure. That is little comfort to you, I’m sure.

Here’s an idea for finding the leak (you probably want an independent mechanic to do this; the dealer is probaly more expensive and does not sound creative enough to do an unusual job): remove the gas tank so you can see water dripping into where the tank would be; then hose down the car selectively until you can trace the water back to the leak. Somebody will have to be under the car to look for water, but at least the water will not be getting into the tank. Indeed, just removing the gas tank might reveal something.

My completely uninformed guess would be to start hosing around the filler neck. I think a leak there – or at the fuel pump hatch (if there is one) – is more likely than a fissure in the tank. And remember that the leak path could be very sneaky – say from the forward edge of the trunk lid down inside some body panels. The time from when water enters the leak path until it hits the tank could be a few minutes. This job could take a while. But think how good you will feel when you get it solved!

Air comes in to replace the displaced gasoline through the charcoal bed in the charcoal canister.

If the charcoal bed were ulling water it would saturate and choke the pump off. Wait a minute, perhaps that’s the answer…I’ll post at the thread’s end so this doesn’t get missed.