View Full Version : Milky greenish oil in chevy V8

Tony Jones
11-23-2005, 06:19 PM
"Hi, I found this forum while trying to research a problem I've found in a boat I just bought.

The boat is a 1990 Harbercraft/Jetcraft 1975XL with a Chevy V8 w/ a Kodiak pump. There are about 430 hours on the engine.

When I bought the boat the guy selling it to me ran it, pointed out various things for me, told me the batteries didn't seem to be holding a charge, etc. Stupidly I did not look at the oil. Now a month and a thousand miles of towing later, I finally have had some time to play with my new toy.

Before starting the boat I checked the coolant (a little low), and the oil... which was a very consistant cloudy / milky gray-green. I've seen a couple blown head gaskets before (Cars), but they always showed as some froth / milkyness at the top of the dipstick - this was a consistant color / texture the entire length. After that I started the engine and ran it for a about 30 seconds - sounded ok.

So, given that suposedly the boat has not been run much this or last season is there anything this could be besides water in the oil? If not, is there anyway that water could get in the oil other than a head/block leak? (condensation?)

Also, what should the oil look like if if there is water in it? I would expect the water and oil to separate if left long enough. Is this true or false?

Anything else I should look at? I was thinking of starting the engine and looking at the coolant resevoir to look for bubbles - is this safe or am I going to destroy my engine trying this?

I don't mind getting my hands dirty and I'm reasonably handy, but do not have any space to work (or many tools). What should my next move be?

If it is a head gasket, any idea on the aproximate cost of having a mechanic replace it? Can anyone suggest a good / reasonable marine mechanic is Seattle?

Any / all help is greatly apreciated! Thanks, Tony"

Eddie from Oregon
11-24-2005, 10:24 AM
"You should have had the boat surveyed or had a mechanic look at the engine unless you got the boat so cheap that the cost of the repairs is irrelavent. At this point, get a mechanic to look at it."

11-26-2005, 04:44 PM
"It's quite possible that moisture built up inside the engine during sitting (and neglect from a lack of oil changing). I'd change the oil and filter, fire her up and run it for an hour or so. If the 'milkshake' returns you're screwed. If not...Whoopee!


PS: As Eddie said, get a surveyor before buying a boat! At least have a competent mechanic check it out."

Tony Jones
11-27-2005, 02:33 AM
Eddie - you are absolutely right. Thank you so much.

Jeff - Pretty much what I had decided to try. Thanks (really) for answering!

Eddie From Oregon
11-28-2005, 10:38 AM
Live and learn. At least you moved on a situation and did something. Good luck."

11-28-2005, 09:16 PM
"Dear Tony--don't take the criticism too hard. Think how foolish some of us feel that have had their purchases surveyed only to later find problems like yours or worse. Most surveyers include enough legal-ease in their contracts to weasel their way out of any liability for their oversights. The last one I paid couldn't find his rear-end with both hands, let alone a problem like you may have."

04-08-2006, 07:18 PM
"If it's greenish and has closed cooling, there's a leak somewhere, probably a head gasket (hopefully) although it could be the intake manifold or gasket, too. Are there any new freeze plugs on the motor? Look hard because there are a couple behind the motor mounts. If there are any new ones, it froze.

Motor oil that has mixed with water in a motor that has been running gets really thick, like a milkshake. At room temperature, you'll have to wait a long time for it to separate. It'll never happen that way. Look into the oil filler- there's probably a lot of it inside the valve cover. I don't like to be the bearer of bad news, but I've seen this before and it sucks. If you want to do it yourself, you can, but call around and ask what the marinas near you do when this happens. Most may recommend a total teardown and cleaning. If it hadn't been run, it would be a lot easier to get the mixture out.

Cope and MC Phetters (sp?) is expensive, but I have heard that they're good. The BBB may have listings and # of complaints for anyone in the area, as well as the outcome of the complaints."