Waterboy may have hit the answer.
Air to replace the gas pumped out is drawn in through the charcoal bed in the charcoal canister under the hood. Is it possible that somehow a puddle is forming in that area and water is being drawn in until the charcoal bed saturates and the tank vacuum builds and chokes off the pump?
I know it’s a stretch, but this whole problem is a strange one.
Okay folks, I should have an answer real soon!
I had the car towed to a licensed and reputable independent garage last Friday. The mechanic just called me and said that he thinks he’s found the problem, but he wants me to see it before he takes action. He also said there are 5 GALLONS of water in the tank!
Hopefully, I’ll check back this evening with a more definitive post.
Five gallons! Whoa!
Please come back to give us the details as to what this mechanic found.
This should be instructive for all of us, including the dolts at that Nissan dealership. When the real cause is found and documented, why don’t you go back and show them what a competent mechanic finally figured out?
Perhaps you can take some digital photos to show the Nissan folks. Maybe you can even shame them into refunding some of the money that they took from you without providing a solution!
I think it was Mountainbike (is that the right name?) who said:
" 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."
What seems to have been the problem is a small plastic box - about the size of a cigarette box, with one end opened and a small hole at the opposite end. The semi-closed part is sort of slanted (like a lean-to hut).
This small plastic box is mounted inside the rear bumper.
Neither I nor the independent mechanic are sure of what this little plastic boxes function is, but a vacuum hose of some sort leads from it to the CHARCOAL CANNISTER.
Now the charcoal cannister seems to draw air through this little plastic box - which was filled with leaves and other debris-causing it to stop-up.
Apparently, water has been draining over the rear bumper and somehow, ending up in this plastic box.
Now the charcoal cannister seems to have been sucking water from this plastic box. It also seems that the cannister continued to suck any and all water that cascaded over the bumper. The independent mechanic said that he found no less than FIVE GALLONS of water in the gas tank!
We have not finalized the problem or the fix. This charcoal filter does seem to be at least a part of the problem.
Now, on to Nissan. It just seems to me that after the 2nd report of water in the gas (and certainly by the 3rd or 4th reports) - Nissan’s EXPERT should have at least thought about this.
I’ll post more tomorrow when I have more facts.
Thanks again to everybody who read my thread and offered valuable constructive advice!
RB
One more thing: is there any way to post pictures in this forum?
The little plastic box is a vent, or intake device.
Repair is underway. I am now battling with Nissan. They don’t seem to think that they should have to pay a “3rd party, independent” garage for fixing a problem that they could not locate - after 4 tries. I’d also like some of the money refunded from the dealerships, since they never actually fixed anything.
We’ll see how this plays out!
thanks again folks!
RB
Yup, it was me, but I have to extend credit to Waterboy. Multiple head really are better than one.
Glad you solved this. This one was a test worthy of an ASE exam.
Sorry, but I’m not buying it.
How does FIVE GALLONS of water make its way past the bumper (or bumper cover), into this small plastic box (whatever its function), then through a vacuum hose to the charcoal canister, as you wash your car with a garden hose, when the engine is not running and there’s no vacuum?
Or when it’s raining and the car is not moving?
How does that much water follow such a circuitous path, with no vacuum?
And you still can’t smell gasoline. No leak out, no leak in.
Riddle me that, Batman!
PS. What’s the fuel mileage on this Sentra? I hope you’ve been measuring it.
Vacuum does develop as the gas is pumped out. And as long as the water keeps sinking the engine will keep running until the water level reaches the pump pickup.
It’s the best theory I can muster.
Before weighing in further on this would someone please explain something to me.
Five GALLONS of water in the tank? I’m not buying that for one single minute.
Water always sinks to the bottom of the tank. Even a 1 gallon quantity is going to cause either a fail to start situation at worst or a bucking and jerking situation from the moment of startup at best.
With 5 gallons of water in the tank this means the pump is sucking nothing but H2O and unless someone has figured a way to make that water2gas scam actually work the car is not going to even start, much less move itself out of the driveway.
So anyone want to 'splain to me how a car with 5 gallons of water in the tank actually even made it to the side of the road? Any road?
I think five gallons is enough to cover the fuel pump pickup. How would the engine even start?
And how would five gallons get in the tank while the car is parked and the OP is washing it with a garden hose?
Thank you, ok4450.
As usual, ok4450 has raised a very good point.
There probably is water in the gas tank.
But–5 gallons? No.
This mechanic wants the OP to believe that approximately 1/3 of the tank was filled with water, and that is just not credible.
As ok correctly pointed out, the OP would not have been able to drive the Sentra to this indy mechanic if that quantity–or even anywhere near that quantity–of water was present in the gas tank.
The new mechanic may well have found the route that water was following in order to enter the gas tank, but now even this mechanic is questionable–at least in terms of the honesty of what he states. He may have found some water in the tank, and he may have found how the water got into the tank, but he most definitely did not find 5 gallons of water in the tank.
Once someone begins telling lies, that puts everything that he says in question. Since the “5 gallon” statement is clearly not true, then perhaps it is also reasonable to question the other statements made by that mechanic.
I don’t know, but I cannot imagine any other way to any significant volume of water to get into the tank. If the PO’s last post is correct in that the problem is fixed, that would tend to validate my theory.
My guess with the garden hose is that the box is filling with water and the water is being drawn in when the engine is started. It certainly could not get in any other way that I can see.
Hey, that’s my theory and I’m stickin’ to it!
I hate to pop anybodys bubble but my sons Sentra has developed exactly the same problem and we have been told exactly the same thing by the local Nissan dealer. Now after spending almost $2500 getting it “fixed” we are at wits end. I am glad to find that we are not the only ones experiencing this problem, and that the solution may be fairly easy. As for 5 gal of water in the tank , that seems to be excessive, but that is exactly what my sons car had in the tank - or so we were told by the dealership. They showed me a sample of the gas removed from the tank and there was about 1/16" of gas floating on about 1/2" of water. So I don’t really care if you believe the “5gal” statement is true or not as , in our experience it is a definate fact. Now we have some ammunition to go after Nissan and get this problem resolved.
If a fuel tank has 1 or 2 gallons of water in it then is either not going to start at all or if it does start it will likely not run but for a few seconds and will run so ragged that it’s not going to make it to the side of any road.
Water always settles to the lowest point in the tank and the pump always siphons from the bottom so water is going to be the first thing inhaled.
You trust this Nissan dealer who hit you for 2500 bucks and THEN shows you a fuel sample?
What was this 2500 dollars for? Removal of water in the tank and blowing the lines out should not run but a pittance of this amount.
Any chance they were throwing parts at your car in an attempt to repair a rough running problem, finally hit the nail on the head, and showed you a sample which may have been taken from the water cooler?
Still ain’t buyin’ it but I’d like to hear a breakdown of this 2500 dollars.
A small jar with 1/2 " of water and 1/16" of gasoline only proves that there was SOME water in the tank. It doesn’t prove there were five gallons.
I’m beginning to think these Sentras have the “funnel” option, because only with a large funnel could you get five gallons of water in the gas tank during a rain storm.
Washing the car? I still don’t believe it.
For the record, I discount the 5 gallon figure as a misunderstanding, an exaggeration, or perhaps a misrepresentation by a tech. That’s an unrealistic scenerio.
However, since clenaing out the box that was clogged with leaves fixed the vehicle, and since I still believe the suction theory to be valid, and since I still cannot see any other way water could continue to get into the tank every time it rains, I’m going to suggest that the “fix” was good and the 5 gallons was incorrect.
The main reason I’m postung again is because I noticed that “aditat2” posted recently with the same problem and I wanted to be sure the “waterbox & suction theory” was at least considered as a possibility and not discounted. I’d rather be thought twice a fool and help someone than to have a possible “fix” disregarded by someone in need.
Those are my thoughts exactly, MB.
What I’d still like to know is how the 2500 dollars was accounted for (“at wit’s end”) before a simple watered gas problem was found.
Twenty five hundred bucks before a water/gas sample raises a red flag or two.
It still boils down to no matter how water got in the tank. It will quit running long before the 5 gallon mark and quite likely the 1 gallon mark.
The 2500 breaks down like this:$60 tow to the dealership.
the first 1400 was to “drain” the tank of the contaminated gas and replace the fuel pump and some other part that supposedly went bad because of the water in the fuel. It ran ok for about a month then came a heavy rain storm and the next day the car made it about 2 miles on the gas in the line before comming to a stop on the side of the road. There went another $60 fo a tow and 400+ at the dealership to drain the tank and do whatever the hell they do. It was at this point that we were showed a "sample"of the water found in the tank and told by the service manager that there was at least 85% water and the rest gas. Car ran fine for about 3 days then came - you guessed it - another rain storm. 2 miles down the road and the car was dead again… Another 60 tow and 400+ at the dealership. Again they showed us a sample of the gas they supposedly took from the tank and again said that there was at least 5 gal. in there. They, too, supposedly did a pressure test on the system and said there were no leaks. Their response is that we have somebody pouring water into the tank and there is simply no way that can be happening since we live out in the country about a mile off any paved road. We have motion sensor lights and cameras and even had the Sheriffs Dept do extra patrols just to make sure. This morning I confronted the Nissan Dealership with a copy of this thread and was again told that there is no way water can get into the system. My son and I had pulled the charcoal cannister in question and guess what - not only was it clogged up but it was full of water. This was after another rain storm! We had another storm last night so I know that there is even more water in there now. Even with our checking this problem ourselves the Nissan people refuse to acknowledge that there is a problem with the car. Oh - and like Rusty1 - this is a 2003 nissan sentra.