water in fuel sensor

S

SmokyMtnGrady

Well-Known Member
Joined
Jul 11, 2009
Messages
2,021
Reaction score
507
Points
113
Over the past two months under high rpms as in above 5400 my F250 guages are indicating water in the fuel. I have checked both filters and replaced the 10 micron one twice. I have yet to actually find any water in the fuel when I pour it in a jar (I let it sit a while too).

When I slow down to under 5,000 RPM the indicator stops warning me. It also only stays on for a minute or two when it does warn me. I ran to the Bahamas and back and it happened twice on that trip. It happened last week on the lake once and the warning lasted maybe 20 seconds and stopped and it did not happen again.

So is it a faulty sensor? It was replaced right off the bat when the motor was new. Any ideas. Would be appreciated. Thabks.
 
Where is the water sensor located? If it's in the VST tank or a separate enging mounted water separator tank, have you drained those yet?
 
Brian on the F250 it is located in/on the engine mounted filter with the clear polycarbonate vessel. It seems to me if we had a water issue with water at the botton of the gas tank then would it not be evident in both the big and small filters?
 
Faulty water in fuel sensors are a pretty common problem with the larger Yamahas. But sometimes the intermittent warning is just the result of the little float ring bouncing to the top of the filter in rough water.

You should also check the sensor wiring and electrical connections down into the bilge area. Sometimes they get wet and will give you the signal.

If you got your bilge wet in the Bahamas, you might still have the issue now that you're home. I would flush it out with fresh water (you're supposed to do that every 6 months anyway) and let it dry out good. Then check your connections and hit them all with CorrosionX spray. That stuff has changed my life here in Florida.
 
This is a know issue with certain model engines with the water sensor electronics. There may be a factory tech note on this issue but right now after a few beers, I can't remember ( I am home, not driving and not boating!)
 
I recently had a problem on one of my F250s, but the sensor had failed open (no warning). It was covered under warranty. It's interesting that you only get the warnings, both engines I assume, under higher power (fuel flow). If the two wires leading to the sensors short out you will get a warning. There is an internal magnetic switch in the sensor that is triggered by the magnetic float moving up to a certain point. That float has a specific density less than water, but more than gasoline. It floats on the water, but stays below the gas. Given the high fuel flow circumstance, it could be that the flow is being slightly restricted by a clogged filter, somehow causing the flow to raise the magnetic float. Have you changed the small paper filter? They may look fine but may be restricitng the flow. Too much air in the filter might also mess up the float. Just a guess. If the warnings were intermittent, I'd suggest looking at wiring issues, but the predictable nature you describe leads me to look more closely at the magnetic float. If you unbolt the filter from the engine and turn it upside down you should get a warning. Right side up and the warning should go away after a delay. Good Luck!
 
Thanks.guys. i will look into the float. The engine filter was replaced in April. I replaced the big 10 micron one twice now. I suspect it is the float as well after reading yalls input. I will do some digging and report back.
 
You must log in or register to reply here.