View Full Version : Herebs the Age Old question Old Diesel Fuel

06-03-2008, 02:33 PM
"I have about 200 litres of Diesel Fuel in my boat, I've just istalled a 3GM30 Yanmar and am wondering should I take a chance on the fuel? It's about a year old or a little more than that maybe 15 months. And before you ask no, I didn't put stabilizer in for the winter lay up ... just didn't get to it. Is the fuel shot or can I filter it or is there some sort of rejuvinzer I can add? 200 litres of fuel up here is worth about $300 and as you can imagine I really don't want to just dump it if I can avoid it ... thanks for your advice(s) in advance."

06-04-2008, 03:16 PM
I haven't received a resounding amount of replies on this but one local Diesel mechanic up here suggested that I add some Kleenflo to the tanks - any thoughts one this?

06-27-2008, 09:51 PM
"As long as that product does not have the fuel injector system killer "alcohol". Change your fuel filter and seperator filter and it should be fine. Some add a biocide to control algae.
We found underground diesel fuel in tanks and scavanged 20 barrels. We used it for testing out diesel electic sets. We figured the fuel was 20 years old. It worked fine. Gasoling goes stale, not diesel ...."

06-27-2008, 11:52 PM
"Thanks for the reply Ron - I've since run the little darling up with the fuel as such. Had a few people "smell" the fuel and it appears to be quit OK. When I ran it there was little or no smoke which seems to be the telltale around here. Again thanks for the reply. Not sure what biocide is or does but I will look for some of the product, I assume it will have directions as to how much to use."

06-28-2008, 07:02 PM
"Diesel fuel tanks sweat and condensation forms. Algae may grow in the tank and will block fuel injectors and pumps. So Racor along with others make a biocide to add to diesel fuel to kill the algae and then get cleaned by your fuel filters. Take a sample of diesel fuel in a small clean baby food jar. Place in direct sunlight for a few hours and if it turns black, you have algae."

06-28-2008, 07:58 PM
Thanks for the leave in the sunlight tip - I'll have a look in the morning. I'll for sure have a look for Biocide too.

07-03-2008, 09:49 AM
"Greetings, You may want to get some Startron at your local West Marine or similar store.It digests the Algea allowing it to be injected and burnt."

07-11-2008, 10:41 PM
"Well I thank all for their advice.

I took the bull by the horns and drained one of the tanks 5 gallons at a time and walked them up to the use fuel depot. Then I opened access panel and found 1/2 inch of black sludge all over the inside of the tank. My game plan now is to scrape it all to the bottom corner of the tank and dip it out then rinse with varsol.

As the fuel drained out, it was orange at first and then as I got to the bottom of the tank it was quit black in colour which seems to indicate bacteria.

I have to admit it was one hell of a job but I glad I acted on advice I received here.

I plan on changing the gate valve that is on the tank with a ball valve and do the other tank at a later date (they are individually valved and piped).

Trust me from this day on I will never leave a tank of fuel without conditioner in it ...

Again thanks for all the advice ..."

07-24-2008, 09:45 AM

Thanks for the tip. Sounds like a great and easy way to test for the algae!