Water In Fuel Tank Causing Fuel Pump Damage?

Reader Question
Hello from Virginia,

Firstly, when I looked you up to ask you the following question, I sincerely didn’t expect to get an auto insurance ad.

I did the darn thing tho’ and, after I do a thorough check of their customer’s satisfaction thru the normal avenues, I think I might actually switch to Encompass. I think I might save about $1100 a year and maybe more when my daughter gets her permit because they don’t charge for permitted drivers; they just need to know they are driving!

Trust me, this is a phenomenon I’ve never seen and I’ve been with 3 insurance companies over the last 27 years and checked into I don’t know how many others. Obviously, I bookmarked a lot of pages to show my wife.

Anyway, onto my question, which I can honestly say, I’m not sure has been addressed in much depth. I have spent……….. I don’t know, I would guess 12 to 15 hours researching before I finally gave up.

The problem I have is that, for reasons I need not go into here, the level of our company’s delivery van’s gasoline tank (say that 3 times in a row real fast) is kept low at all times.

In the last 4-1/2 years I have been here, the engine, when extremely low on gas starts to rattle and doesn’t stop until we fork over several hundreds of dollars each time to a mechanic.

The fact that the check engine light and rattling begins when the fuel is either out or all but out, leads me to think that there is water in the tank due to all the reasons that water gets into tanks, blah, blah, blah.

What I’m interested in, if I am correct in that it is the water in the tank getting into the engine that is causing the problem, is what is the mechanism at work here, ie. what is physically happening in the engine that disrupts its operation so severely that mechanics seem to be living in larger & larger houses with each visit we make.

I imagine one issue may be the uneven explosions occurring in the various chambers, which I’m thinking is bound to put the drive & cam shafts into stress, throwing the timing…. but this is just a guess. Also, is it possible that vapor lock………..? Just conjecturing.

Be well,


Thanks for your email Lee,

It’s fairly common for the bottom of the fuel tank to contain dirt, rust, and some water droplets. The best way to prevent damage to the electric fuel pumps (which is located inside the fuel tank) is to refill the tank when you are at 1/4 of a tank or slightly less…don’t wait until tank is on E.

When the tank is empty the fuel pump starts to suck up all that junk and send it to the engine. That junk damages the pump, restricts the fuel filter, clogs the fuel injectors etc. etc so the engine runs bad and eventually the pump blows up and dies.

Your problem is probably not water, but sand and grit which damages the fuel pump. I would also buy fuel from big brand names, not from your local convenient store, where the chances of getting contaminated fuel is greater than from the big name brands. I would also buy fuel from a busy fuel station that is always receiving clean fresh fuel on a daily basis.

I would also replace your fuel filter about every 15K miles, this will reduce the strain on the fuel pump and extend it’s life span. Delivery vehicles with multiple drivers are expensive to maintain! If you can give more “ownership” of the vehicle to the driver, and make a dedicated driver and hold them responsible for the care and maintenance and appearance of the vehicle you will cut your repair expenses.

Keep a log of fuel purchases, try to figure out your fuel economy MPG, do a weekly random check inside and out of the vehicle to see if it is in good shape and clean. Have a check list the driver must check and sign each day, check all lights, check tires, look under the vehicle for any fluid leaks, check oil level, check for cleanliness etc. etc.

The driver with the lowest expense bill, cleanest vehicle, most improved MPG etc. etc. gets a free dinner for two at a nice restaurant or tickets to a ball game or what ever your guys like to do with their free time. Give them an incentive to help you reduce costs, and keep the value of the vehicles high.

Thanks for getting an auto insurance quote.
Austin Davis

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