water in gas tank

rebel77 · January 18, 2006

I believe I have water in the gas tank. I think I have some bad gas from a station.

A few people in town have claimed the same. I believe that maybe I filled up when there storage tank was real low. anyway,. the symptoms were running really rough, black smoke every once in awhile out of the exhaust, almost stalling when coming to a stop, also some water coming out of the exhaust. I went to auto zone and had them run the codes for the check engine light, it said something about too lean of a mixture of gas and mis firing. What I did was put a can of dry gas in, an filled up the tank with BP mid grade. There was a 1/2 tank of gas. The truck seems to be running much better now. Still has a slight miss in it, the gas is not run through yet. My question is, should I put in new plugs, and a fuel filter? 2003 silverado 5.3. Where is the fuel filter located? Please help. Thanks.

asepgrad98 · January 18, 2006

also some water coming out of the exhaust

that is normal.

i wouldnt worry about the plugs, change the fuel filter(along inside of left frame rail) if it hasnt been changed in last 30k miles.

jhm · January 18, 2006

I believe I have water in the gas tank. I think I have some bad gas from a station.
A few people in town have claimed the same. I believe that maybe I filled up when there storage tank was real low. anyway,. the symptoms were running really rough, black smoke every once in awhile out of the exhaust, almost stalling when coming to a stop, also some water coming out of the exhaust. I went to auto zone and had them run the codes for the check engine light, it said something about too lean of a mixture of gas and mis firing. What I did was put a can of dry gas in, an filled up the tank with BP mid grade. There was a 1/2 tank of gas. The truck seems to be running much better now. Still has a slight miss in it, the gas is not run through yet. My question is, should I put in new plugs, and a fuel filter? 2003 silverado 5.3. Where is the fuel filter located? Please help. Thanks.

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I dont know about your state, but we have a Dept of consumer protection that will investigate these types of complaints. A few years ago they tested a stations fuel after getting complaints and made them pay for all required repairs to customers vehicles. Dry gas will absorb a little water but if there is more, the tank must be drained. Adding higher octane fuel will do nothing.

rebel77 · January 18, 2006

How exactly do I drain the tank? Is it a diy job? I will look at changing the fuel filter.

pm26 · January 19, 2006

I got gas mixed with water into my motorcycle tank twice in one month (two different gas stations) several years ago. The bike missed terribly, which led me to believe that I had an ignition problem. AFter taking out the plugs and checking all the ignition components, I removed all four carburetors, disassembled them, and found nothing. FinallyI drained the tank. It was just water in the fuel. All that work for nothing. Filled with fresh gas and bike ran great again.

I too would recommend draining your tank. There is no drain plug on the tank, so there are only two ways to do it: Either siphon the gas out until the tank is almost dry(easier option), or remove the tank from the truck and drain it and flush it (PITA approach).

highrides05 · January 19, 2006

Agree with everyone else drain the tank for best results, first drain all the way then fill it up again but also add about 2 bottles of HEET in the tank in will help with everything that was left behind, there is also a hex head screw on the fuel pump which you can turn the key on, but not all the way to where it starts just enough for everything to turn on, and then turn the key off and get under there with a coffee can or something like that to catch it in and back that hex nut off a little bit and you will notice alot of it will be water and very little fuel, you can keep on doing this over and over again, will not hurt anything at all, after a few times you will notice a difference of the stuff in the can and also the smell of it because when you get to the good stuff it will be alot stronger.

note not all the fuel pumps are the same if you have it you well see it, just looking in the frame rail right under your drivers side door and you will see all the fuel lines going to it and hex or star head set screw or cap whatever you want to call it is right there facing towards the passengers side, now if you take that screw out and nothing happens you have different one.

tarantula · January 19, 2006

A gas station tank being low won't make any difference with water being pumped, since gas floats. As for the black smoke and lean condition, they don't make sense really. Black smoke in any other car signifies rich condition usually, but not lean. The misfire is probably leading to the smoke. My truck has gotten that before, and a tune up helped get rid of it. Not that this is definitely the same in your case though. If you really think you have a lot of water in your tank, then draining is the way to go. Otherwise you can just try a couple tanks with a couple bottles of good drygas.

My $.02 ;