Rainbow colored bilge?

(cocheese) · (cocheese) **Join Date: Jul 2004** 05-21-2009, 7:23 AM

When we leave the lake, we pull the plug when the boat is on the trailer. We pull the plug every time and is part of our wipe down routine. I have noticed this season that something is polluting the water in the bilge. The water has a rainbow tint to it. What is it? Is it gas, oil, grease....? I thought that it might be gas from a recent overflow when pumping, but after a couple of weeks and riding four to five times a week, it is sill a rainbow colored bilge leaving the boat. Any ideas? The boat is a '05 Supra Launch 21V.

(rbeckei) · (rbeckei) **Join Date: May 2007** 05-21-2009, 7:29 AM

It is GAS. You have a leak or it could be residue left over from your overflow.

(dhcomp) · (dhcomp) **Join Date: Jun 2003** 05-21-2009, 7:42 AM

Put plug in. Get some good degresing dish soap, put some in bilge, fill a couple inches with water. Swish around and scrub where you can.

Let it drain.

Flush the hell out of it til no more bubbles are present.

Then you'll have a clean bildge, and will know if its a continuing problem, or old residue. Takes a long time for gas to leave the bilge, so you might be just seeing the same leak over and over

(cocheese) · (cocheese) **Join Date: Jul 2004** 05-21-2009, 7:52 AM

Thanks! Was planning on parking it on a hill and run a water hose in the front with the plug out and see if it would clear up. Didn't think about the dish soap. I will put some water in and take it for a ride and then flush it when I get home. If it is a leak, it is a slow one. Can't really tell any difference in fuel use.

(Message edited by cocheese on May 21, 2009)

(ttuclint) · (ttuclint) **Join Date: Sep 2003** 05-21-2009, 7:58 AM

Probably some oil that spilled during an oil change, doesn't take much.

(silvermustang35)

Had a similar thing happening with my I/O and started looking after cleaning out the bilge too, and found it was just a loose connector on my stern drive fluid. It leaked so little to not see a considerable difference, but just enough to see rainbow colored water out of the bilge...

(Message edited by silvermustang35 on May 21, 2009)

(cocheese) · (cocheese) **Join Date: Jul 2004** 05-21-2009, 8:11 AM

It was doing it before I changed the oil and I was really careful not to spill even a drop when I changed the oil. Not saying that there is no possibility that a drop didn't spill, but it started soon after a overfill at the gas pump. Gas seems more likely. If it is a leak, where and what do I check. I pulled the floor out and checked the gas tank for obvious leaks tried to smell for leaks, but really don't know what I am looking for.

(trickyboarder08)

Started after an overfill at the gas pump? Clean your bilge with soap like dhcomp suggested and i'd bet you'll stop seeing your rainbow.

(jmanolinsky) · (jmanolinsky) **Join Date: Dec 2005** 05-21-2009, 9:05 AM

A gas leak should be easy to detect. It doesn't take much of a leak at all to easily smell it.

(tgoin) · (tgoin) **Join Date: Apr 2009** 05-21-2009, 9:26 AM

And ... as far as I know, if your bilge pump
were to run, while this is in there, and you
discharge that "rainbow" into the water, you could
face MASSIVE MASSIVE fines ... best to get it
checked out.

I had a leak for a long time I could NOT find, and it turns out there was a hairline crack in my
remote Oil Filter hose that would only drip a little
under pressure.

(ncsuuh) · (ncsuuh) **Join Date: Jan 2007** 05-21-2009, 9:44 AM

Be carfeul with bilge pumps and fuel. There was a situation on my lake where one of the fuel lines was disconnected and the bilge was soaking it all up. After they filled up they pulled away and the boat exploded. Not saying this will happen but just putting it out there.

(seth) · (seth) **Join Date: Sep 2002** 05-21-2009, 9:54 AM

I have an oil leak that does the same thing. Make sure your bilge is dry and let it sit for a day or two and then check your bilge for any new oil puddled up.

(bill_airjunky)

Yep, use your blower a LOT till you get this figured out.

Seems like an overflow of gas would leak outside the boat, down the side of the hull. Even the vent blows gas outside, not in the bilge.

Check that all your hose clamps are tight. Check that your oil filter is screwed in tight. Maybe even pull the oil filter & check that the filter gasket is present, in good shape & that there is only one gasket in there.

(greatdane) · (greatdane) **Join Date: Feb 2001** 05-21-2009, 10:12 AM

Its oil or gas so it should not be taken lightly. It could simply be oil from your last service and a little grease breaking soap should help flush it out. Just use soap that is non-foaming so you don't get a lot of bubbles as it rinses out. For example, dishwasher soap is made to not foam.

(cocheese) · (cocheese) **Join Date: Jul 2004** 05-21-2009, 11:30 AM

Oil filter is clean and I did the oil change myself about a week ago. The problem was showing up before I changed the oil so if it is oil, it is coming from somewhere other than the filter. As far as the overflow goes, usually when it spits out at the pump, a little runs down the side of the boat. This time, I don't know what happened, it went up and on the seats. I usually can hear it bubble and stop it before it spits out, but this time it snuck up on me and it went everywhere. I am hoping that is it. Seems like the problem started soon after that. I plan on flushing and scrubbing tonight.

(denverd1)

Whats the trick for filling without spilling?

Read it long ago on a site, but forgot. something like putting a wadded up paper towel in the fill hole with the pump nozzle?? so when it reaches the neck it spits it out maybe something like that.

Anybody know?

(bill_airjunky) · (bill_airjunky) **Join Date: Apr 2002** 05-21-2009, 1:19 PM

I just turn the ignition on & watch the fuel gauge while I'm filling it, then stop when it starts gurgling.

Sounds like it was windy or something when it burped. What a drag.