Motor out of boat, milky oil, engine flush?

[dccordell]

Hey guys.. still working on the 470. It is out of the boat sitting on some blocks. When I got the boat, I knew it had a little milky oil on the dip stick, but when I drained the oil today, all of the fluid that came out was milky and as the flow slowed down as the oil drained out it got really thick and nasty. If I had known it was this bad, I would not have even cranked it up while it was still in the boat.
I can look inside the drain plug on the oil pan and see that there is still a good little bit of the "milk" that isn't draining out because it is so thick. I would like to get this out somehow, and from what I've found on here, using some diesel could be the solution. However, all of the posts I found on this subject talked about actually letting the motor crank up and run with the diesel in the oil. I can't crank the motor yet, and I have all of the oil drained. So what would be my best bet to get that gunk out? I'm trying to stay away from pulling the oil pan, but...

One step at a time with this 470... $$
Daniel

 

[Fireman431]

Re: Motor out of boat, milky oil, engine flush?

Pull the pan. If you have milky oil, you're probably gonna have to pull the carb, intake, and heads to fix your underlying issues.

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

I'm actually doing the carb right now... it's not bad at all, I expected lots of rust but there is very little. The boat this motor was in sat for about 8 years I believe, and could have gotten water in through the carb during that time, even though the flame arrestor was in place. I'm hoping this is where the water came from... I'll pull the pan and clean it all up. Looking at the intake from where the carb goes, it looks pretty darn clean. Once I get it all put back together and running, I'll be able to tell if there is water leaking somewhere... and I know there are TONS of threads on that subject.

When I take the pan off and clean it up, how can I be sure that the rest of the motor is clean from the milky stuff too? This is why I was wanting to do some sort of flush/rinse... any ideas?

 

[6meter]

Re: Motor out of boat, milky oil, engine flush?

Most if not all will drain down to pan. I would remove oil pan and clean it, but then again, I have an engine stand.

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

Haha yeah an engine stand would be great at this point! I'm just waiting for some gaskets to come in from iboats so that I can fill her up and let it run. I'm going to try the oil/diesel 50/50 mix once or twice to get it good and clean.

Question: When I pull the pan, can I expect to reuse the gasket or is it normal to buy a new gasket? If I had known I was going to pull the pan, I would have ordered the gasket with the rest but too late for that. Also, if it will need to be replaced... I wonder if there is a same size replacement for another engine that would be available at the parts store? Just curious... I know we don't generally use auto parts, so I'm not sure, even if it would fit.

Thanks!
Daniel

 

[dannyual767]

Re: Motor out of boat, milky oil, engine flush?

Are you certain that the water in the oil isn't the result of a freeze cracked block? I know that you're in Louisiana but last winter was very, very cold. Is the boat from Louisiana or out of state?

 

[stonyloam]

Re: Motor out of boat, milky oil, engine flush?

Haha yeah an engine stand would be great at this point! I'm just waiting for some gaskets to come in from iboats so that I can fill her up and let it run. I'm going to try the oil/diesel 50/50 mix once or twice to get it good and clean.

You'll be sorrrry!!! Don't dooo it! You will just push all of that crap all through the engine. You can get an engine stand from Harbor Freight for $39. Quit whining and pull the pan, what you described, you are going to need to do it anyway, do it now before things really get messed up. No offense intended, just my opinion.

 

[wire2]

Re: Motor out of boat, milky oil, engine flush?

If you insist on running it to flush it out, use a lighter grade oil, like SAE 20 but without the diesel. Let it warm up to operating, stop it, then pull the drain plug right away. You'll get 99% of the gunk out for the price of a gallon of oil.
Do it a 2nd time if need be.

 

[stonyloam]

Re: Motor out of boat, milky oil, engine flush?

Question: When I pull the pan, can I expect to reuse the gasket or is it normal to buy a new gasket? If I had known I was going to pull the pan, I would have ordered the gasket with the rest but too late for that. Also, if it will need to be replaced...

You can try, but chances of saving the old gasket are poor at best, it has been on there for 20+ years. You can get one on e-bay for about $30, yeah I know, but that is less then 1/2 the cost from Merc. Good luck.

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

Ok, wow didn't know there was so many against the diesel treatment! Was just going by what I had read on here... ok, no diesel then.

I actually just pulled the pan... no engine stand, but I have it hanging by the lift that I used to pull it out of the boat. Not ideal or the safest thing to do but it works, just made sure to not get under the motor as much as possible!

So the pan looks very clean and shiny... no rust at all which surprised me. Taking a quick glance into the bottom side of the motor, I don't see any rust there either. That may or may not really tell me anything though... so I have the pan flipped over and letting the rest of the oil/sludge drain into my oil pan, then I'll wipe it out and get it real clean. I was told that I could get some generic oil pan gasket stock at the auto store to make the gasket. Any thoughts on that?

Last question for this time: The manual says to use a type "SE" or "SF" oil. When at the auto store, the only kind of oil that I could find with this stamp was an oil marked for engines made prior to 1988. So I bought 6Qts... It wasn't any top brand though. Will this be ok? At least for the flush...? It was 25w-40. Not trying to start another "Which oil?" thread....!!

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

Are you certain that the water in the oil isn't the result of a freeze cracked block? I know that you're in Louisiana but last winter was very, very cold. Is the boat from Louisiana or out of state?

Can't be sure about having a cracked/warped block or not yet... I suppose once I change the oil after doing the flush, and fill it back up, if I keep getting water in the new oil that would indicate an underlying problem. I sure hope not, but I'm not getting my hopes up about that.

 

[dannyual767]

Re: Motor out of boat, milky oil, engine flush?

....Last question for this time: The manual says to use a type "SE" or "SF" oil. When at the auto store, the only kind of oil that I could find with this stamp was an oil marked for engines made prior to 1988. So I bought 6Qts... It wasn't any top brand though. Will this be ok? At least for the flush...? It was 25w-40. Not trying to start another "Which oil?" thread....!!

Your engine is older and those were the API oil service classes called for back in the day. Today we are up to SM. Usually, everything is "backwards compatible." There is the question of the lack of zinc in modern oils. This is an issue if your engine uses a flat tappet cam and lifters. Its not a factor for roller cammed engines. Here is a cut and paste from Wikipedia:

API service classes

The API service classes[8] have two general classifications: S for "service" (originating from spark ignition) (typical passenger cars and light trucks using gasoline engines), and C for "commercial" (originating from compression ignition) (typical diesel equipment). Engine oil which has been tested and meets the API standards may display the API Service Symbol (also known as the "Donut") with the service designation on containers sold to oil users.[8]

Note that the API oil classification structure has eliminated specific support for wet-clutch motorcycle applications in their descriptors, and API SJ and newer oils are referred to be specific to automobile and light truck use. Accordingly, motorcycle oils are subject to their own unique standards.

The latest API service standard designation is SM for gasoline automobile and light-truck engines. The SM standard refers to a group of laboratory and engine tests, including the latest series for control of high-temperature deposits. Current API service categories include SM, SL and SJ for gasoline engines. All previous service designations are obsolete, although motorcycle oils commonly still use the SF/SG standard.

All the current gasoline categories (including the obsolete SH), have placed limitations on the phosphorus content for certain SAE viscosity grades (the xW-20, xW-30) due to the chemical poisoning that phosphorus has on catalytic converters. Phosphorus is a key anti-wear component in motor oil and is usually found in motor oil in the form of Zinc dithiophosphate. Each new API category has placed successively lower phosphorus and zinc limits, and thus has created a controversial issue obsolescing oils needed for older engines, especially engines with sliding (flat/cleave)tappets. API, and ILSAC, which represents most of the worlds major automobile/engine manufactures, states API SM/ILSAC GF-4 is fully backwards compatible, and it is noted that one of the engine tests required for API SM, the Sequence IVA, is a sliding tappet design to test specifically for cam wear protection. However, not everyone is in agreement with backwards compatibility, and in addition, there are special situations, such as "performance" engines or fully race built engines, where the engine protection requirements are above and beyond API/ILSAC requirements. Because of this, there are specialty oils out in the market place with higher than API allowed phosphorus levels. Most engines built before 1985 have the flat/cleave bearing style systems of construction, which is sensitive to reducing zinc and phosphorus. Example; in API SG rated oils, this was at the 12-1300PPM level for zincs and phosphorus, where the current SM is under 600ppm. This reduction in anti-wear chemicals in oil has caused pre-mature failures of camshafts and other high pressure bearings in many antique automobiles.

 

[stonyloam]

Re: Motor out of boat, milky oil, engine flush?

Are you certain that the water in the oil isn't the result of a freeze cracked block? I know that you're in Louisiana but last winter was very, very cold. Is the boat from Louisiana or out of state?

If a 470, it should have been filled with antifreeze, so the block should be OK. If the block has been drained make sure that you refill it with antifreeze mixture, water alone (as I have been told) will not work.

 

[6meter]

Re: Motor out of boat, milky oil, engine flush?

Get a pan gasket that is specifically for the motor. Auto parts stores around water usually have books for boats. It will be worth the price especially if you have to pull the motor again cause it leaks oil. I was gonna suggest using the engine hoist that you used to pull the motor but I figured you didn't have it anymore.

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

Going to try the local merc shop today to see if might have the oil pan gasket... sure wish I would have ordered it with the rest of the gaskets from iboats!

And yes, the motor actually did have "good looking" anti-freeze in it, and our winters aren't extreme down here in Louisiana, so I'm not worried too much about it having froze. Sounds like these motors don't take an overheat well at all so that I AM worried about..

 

[stonyloam]

Re: Motor out of boat, milky oil, engine flush?

Going to try the local merc shop today to see if might have the oil pan gasket... sure wish I would have ordered it with the rest of the gaskets from iboats!

And yes, the motor actually did have "good looking" anti-freeze in it, and our winters aren't extreme down here in Louisiana, so I'm not worried too much about it having froze. Sounds like these motors don't take an overheat well at all so that I AM worried about..

When you see the price, you sure will. Try NAPA they should be able to get you a Sierra gasket for 1/2 the price.

Most of the overheating problems occurred with the 3" diameter heat exchanger which was marginal at best. If you have the later (mid 80's) exchanger they work a lot better. Make sure the impeller is OK and you should be fine. When you get this monster running, do a compression check to make sure the head gasket is OK. Welcome to the "470 club"

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

I like the NAPA idea, but what should I ask for when I go there? Is there another engine that would have the same gasket? Only reason I'm considering it is because the other gaskets that I need to get it running will be in tomorrow, so I've become anxious to fire it up!

And I checked it and it has the 4" heat exchanger (wew!) so maybe this thing hasn't been overheated. I changed the impeller and I was surprised that the old one looked very good! Not brittle or hard and no cracks/missing pieces at all. I changed it anyways and saving the old one, dout I'll ever use it though since it's not worth risking it breaking.

Curious.. how much is a compression gauge? I've never done that before but I would like to check it on this engine... i'm guessing something like this Compression Tester is what I'm looking for? Any special fittings to make this or something similar work?

Thanks for the welcome.. I didn't know this was such a controversial motor until after I found this forum, but I guess that keeps it interesting. Can't "skeer" me!

 

[stonyloam]

Re: Motor out of boat, milky oil, engine flush?

I like the NAPA idea, but what should I ask for when I go there? Is there another engine that would have the same gasket?

Curious.. how much is a compression gauge? Any special fittings to make this or something similar work?

Just ask for their marine parts. Have year, serial number, 470, or Mercruiser 3.7 L. Not that I know of.

Free, borrow one from AutoZone, return it and they will give your money back. Pep Boys might do the same thing, not sure. Pretty easy, run to warm up, remove plugs, screw in gauge, spin, take readings. Repeat after shooting a little oil in plug hole (to seal rings). Note your readings, should be in the 120-160 range, and within 5-10 psi of each other. Let us know the results. Good luck.

 

[dccordell]

Re: Motor out of boat, milky oil, engine flush?

Ok, no luck on the gasket from NAPA. He said he could probably order it but I figure in that case I'm just as well to order it online (and maybe a little cheaper!). It is a kit that also comes with the lifter cover and side gaskets... part number for anybody in the future is: 72479a5. They have it on this site.

Good deal on the compression tester... Just to make sure, I don't actually try to run the motor while checking the compression, right? Just turn it over with the starter? I'll be doing that tomorrow or this weekend I hope!

Daniel

 

[stonyloam]

Re: Motor out of boat, milky oil, engine flush?

All plugs out, just the starter. Best to do it with the engine warm (but cold will do in a pinch).