Feels like water to me... - PeachParts Mercedes-Benz Forum

MikeTangas · #1 11-04-2003, 12:44 PM

what do y'all think?

Background, ran the Suburban nearly to empty and put almost 40 gallons of gas in, di this last Wednesday night. Thursday had a rough running condition, a little worse on Friday, no change for the worse since. Wifey calls me on Friday to say the Suburban was running bad and to bring tools.

Upon arrival I find everything appears intact and agree to drive it home. Once up to speed it runs OK as long as on level ground, once on a hill it sputters bad. Growing up just outside of Houston has me plenty familiar with water in the gas, and this feels the same as I remember. On the way home I did stop by the filling station to see if they have had any water/fuel complaints and to see when the last time they checked for water when dipping the tanks. Their reply was that the drivers dip the tanks and should check for water and they haven't had any complaints. When I pushed the issue a little, conveniently as customers were coming in, the clerk admitted that a "couple weeks ago" they had a leak, but it has been fixed.

Didn't have any time to tinker with the beast over my weekend, but plan on trying to siphon out some fuel from the bottom of the tank to confirm the presence of water.

I really hate the thought of draining $70 worth of fuel to get at a little water, I think I'll try to run it down a bit. I have added four bottles of Heet to try and absorb some of the water.

What else do y'all suggest?

Hatterasguy · #2 11-04-2003, 01:55 PM

I wounder if they make a fuel water seperater for cars? I know thay are commen in boats. Racor is a big brand. If you could figure out how to install one in the fuel line, it would filter the water and you would only have to empty the bowl, when it fills. I'm sure they have a website.

Kestas · #3 11-04-2003, 04:33 PM

You may want to pump some fuel out of the tank by disconnecting the fuel line from the pump and energizing the pump with the ON switch a few times. Put the fluid in a clear jar and look for water at the bottom. This is how I used to do it in the carburator days.

You loss of power could be other things as well. A clogged fuel filter or broken catalytic converter monolith can produce the same symptoms. By running the tank low, the Suburban may have slurped some debris from the bottom of the tank.

MikeTangas · #4 11-04-2003, 06:54 PM

Possible on the debris issue, seeing as how I ran it so low, but it is a fresh filter, only about 3K miles and I wouldn't expect it to plug. I was thinking about pulling it to check.

I am planning on pulling some fuel in a couple minutes, provided I can find my Oklahoma credit card, if not I'll disconnect at the filter and let the fuel pump do the work. As far as the cat, I'll standby on that one, every failed cat I have experienced produced problems at higher speeds/rpm, not low speed, but I will keep it in mind.

william rogers · #5 11-04-2003, 10:38 PM

Living in the North West water in the gas is as common as bear scat on the road. I have had good luck by just adding Heet of any other alcohol based gas treatment. We buy it by the case here in green hell.A friend had to put 5 bottles all at once in his Chevy truck last winter after filling at a water station ........
William Rogers......... Deadwood OR

MikeTangas · #6 11-05-2003, 12:47 AM

It appears the Suburban has an anti siphon device, I can't get my Oklahoma credit card in there (and it is a small diameter one). I fiddled with it until dark, have no intention of working with atrificial light. Tomorrow I'll crack her open at the filter and run the pump, let the car do the work. Maybe I'll get lucky and be able to pump out enough H20 to get the level below the pick-up, then maybe some additional Heet will dry it out.

MikeTangas · #7 11-05-2003, 09:25 PM

Final chapter, all fixed.

Disconnected at the filter, connected a section of tubing to fuel line, ran tubing to one gallon jar. Running the tank mounted fuel pump produced a milky concoction of water, debris and fuel (most likely emulsified by the pump. The filter drained out water and gas. Emptied about 2 gallons until fuel ran clear. Installed new filter and all was well in the world.

Amazing what just a little water can do to you.

Kestas · #8 11-06-2003, 09:06 AM

Bravo! Do you think some water may still be in the lines leading to the engine? When I had these problems, I drained the tank, the carburator, and blew the lines out. This completely eliminated the problem.

Never had much luck with dry gas. If you know your chemistry, it mixes not only with water but also with the gas. Add a pint of dry gas and the water would now be 5% methanol and 95% water -- not very effective.