Home » automotive / marine » Water In Fuel

Water In Fuel

Alright, so today on Repairs101 I thought I’d talk to you a little bit about getting water in your fuel. It’s a problem that almost everybody is going to come in contact with one time or another in their lives… Or at least so they’ll be told. I’ll go through some of the symptoms. I’ll talk about some of the misconceptions. Talk about some of the possible sources — how did the water get into your fuel in the first place? I’ll talk about an old trucker’s trick people use. As well as what really should be done from a mechanic’s perspective.


Shop Car Remotes and save up to 70% at CarandTruckRemotes.com

Today on Repairs101 I thought I’d like to talk about getting water in your fuel. Some people will say that there’s bad fuel or water in the gas… When they really don’t know what’s wrong with your vehicle. Often times it has nothing to do with water in the fuel it’s just a misdiagnosis. It’s become like the way in the Second World War. They used to say gremlins were at work or there was a ghost in the machine.


OK so symptoms of water in your fuel are going to be things like shaking, a loss of power, missing. Things like rough idle. I found that Outboards… When they have water in their fuel… Sometimes the engine will be running and it will seem to have like a sneeze .

DIY like a pro! Shop from over 1,000,000 Repair Manuals at eManualOnline.com! As low as $14.99 per manual. Shop now.

So realistically, any machinery or say fuel cans, jerry cans that are left in the outdoor environment. Introducing condensation to the inside of the can and as it collects it’s going to contaminate your fuel. Now your boats, your inboards, your outboards, jet-skis. Any equipment that’s left out in the marine environment is liable to have water introduced to the fuel. So, even service stations can get water in their tanks through ground water getting in. You know, it might have come from the refinery. It might have come from some storage tanks. Might have come from a pipeline. Might have come from a railcar. Or it might have been in the truck that delivered it to the service station.

Prevention & remedy

So one primary defence that you can use against getting bad fuel is to never fill up at a gas station that is being filled up.

An old trucker’s trick is to pour in a bottle of Isopropyl Alcohol. So you can try isopropyl alcohol, methyl alcohol, or ethyl alcohol. People use these things all the time and it goes back almost to the beginning of internal combustion.

OK now make sure you get 99% because if you get 70%, you’re just adding in more water. The idea is that water doesn’t mix with fuel. It sinks to the bottom. Alcohol and water do mix. It will mix with the water, it will burn and thereby remove the water by taking it with the alcohol. When Diesel mixes with water it does separate to a certain degree. But it also causes a microbial growth that will live in the fuel itself. It becomes cloudy and I refer to it as puke or barf. It really looks awful. And you can generally contain it and keep it from getting as far as the engine using a water separator.

Water separator

A water separator will at least keep it contained from the water separator back to the tank. And it won’t get any further. Unless of course you don’t service her. In which case it’s just a matter of time before the microbial growth finds its way all the way in plugs it up and shuts you down. In some cases calling in a fuel polisher is the best thing.


Fuel polishers

You know, if you’ve got some heavy equipment out in the field. Or a boat, say. Tied to a dock somewhere or even trucks or something like that. Getting a fuel polisher in is often the best solution. A fuel polisher will come in. Pump all the fuel out of your container or tank or machine. And they will pump it through their own filters, extract all the water, all the sediment. Clean it down to about one micron and then pump it back into your machine nice and clean. Now the right thing to do is to empty the tank. And then you’ve got to clean it out, purge the fuel pump, purge the lines. You’re going to need to clean your carburetor out or purge your injectors.

Water finding paste

With a name like Kolor Kut I honestly thought that it was a painting supplies product. Now a tank like this one might be fairly easy to get in to. But yours, on your vehicle or your vessel might be a lot more challenging. Here’s a thirty six inch zap-strap that you can use — these are my favourite. You know you might be able to just use a yardstick like this one.

White zap-strap that I’ve smeared some of this brown Kolor Kut paste — I hope the colour is good for you. As we go through the gasoline you can see before your eyes how it changes colour very-very quickly.

Professional CB Radios from Cobra Electronics