Yup. To bring it back they re- rebrand it as an Engine Assembly Lube, instead of a oil 'supplement.'

http://www.amazon.com/Genuine-Fluid-.../dp/B00BK7LYPW

http://ecx.images-amazon.com/images/...L._SL1500_.jpg

GM EOS (engine oil supplement) was basically an ZDDP additive = zinc and phos

it was GM along with EPA mandates not offer it anymore as Zinc and phos degrade and coat the catalyst sub strake along with its wash coat of precious metals that make up the cat sub strake.

Actually with the Merc muffs that have the wire that passes thru the water inlets I can run my boat on the hose without issue. Merc had a service bulletin out some time ago about making sure not to run the hose wide open if you have a ton of water pressure (which I do) and to idle the motor around 1,200 RPM to prevent reversion. So with my faucet about 2/3 way open I can run my boat on the hose to warm it up to do oil changes, etc.

How can you get reversion from the hose? If your on level ground it should never be a problem.

Drew ^^^^ I am sure he is referring to the post I posted before. The link below and go to post # 9 in that thread, then click on the link for the Mercruiser Service Bulletin.

http://www.offshoreonly.com/forums/g...-question.html

here this will help to as it is the same Service Bulletin from Mercruiser.

http://www.boatfix.com/merc/bullet/99/99_09.PDF

I do not recall a Service Bulletin from Merc about water pressure on the hose being any issue. I think he is still referring to what I posted and the SB is the correct info.

The real reason for lower pressure / volume on the water hose is to get the engine slightly hotter to make flushing easier ie : Salt. rust, scale, crap in the water and so on.

sorry was to busy drinking to look back or care. No worries .

Update. Shop ran boat with no belt and no drive. Still making noise. Stethoscope isolates noise to starboard rear of engine and sounds internal, not external. Borescope shows nothing obvious in #6 or #8. Shop agrees with me that it does not sound like a typical rod, lifter, rocker arm, etc. Noise does not change hot or cold, load or no load, or by shutting down #6 or #8 cylinders. Before pulling motor, shop will pull valve cover and look for broken springs, collapsed lifter, etc. but everything is pointing to the engine having to come out. Video was taken at shop and sent to Ryan at Retter Engine Development (Precision here on OSO) to get his take on noise. If engine work needs to be done Retter will be doing the work. Looks like December before motor can be pulled so it will be awhile before any more updates.

did they do a comp and leakdown test ??? How about checking for ignition spark arc ?

What about a drive coupler bolt coming out. Could have vibrated out when going down the road.

Was told compression good. Leak down not mentioned nor did I ask as I plan to go to the shop later this week to retrieve items from boat and will have more detailed conversations.

Did they put the stethoscope on the oil pan to see if the sound is more prevalent there? Wondering if the windage tray could have shaken loose and getting hit by the crank.

A friend of mine had a noise develop that sounded a little like a lifter ticking. After checking out the top end he finally pulled the motor and tore it down. Turned out that he had hammered out a rod bearing flat as a penny on a railroad track, and it had smashed out and was contacting the main journal webbing. This was on a boosted application.

Not sure where all they put the scope. Will find out more later this week or weekend. Owner said best they can tell it is internal, starboard rear, and not anything they can say they have heard before (i.e. lifter, rod, etc.). Carries good oil pressure as always and oil is clean (only has 15 hours on it). I asked if he took the filter off and cut it open and he said no. Been too soon to send out an oil analysis. At this point, unless removing the valve cover shows something obvious, whether it is internal or at the back of the engine the engine has to come out.

Before taking it to the shop I was able to see the snout on the coupler spinning and didn't see any obvious wobble. I was also able to feel the bolts on the coupler flange. I tried bumping motor over a few times to feel each bolt (no way to know if I got them all) and didn't feel any that were pulled away from flange. To me, it sounded like something hitting the flywheel cover. Again, the weirdest thing is the boat was ran on a Sunday for about an hour and it ran flawless. The following Wednesday it was idled for a few minutes from my slip to the trailer and again, ran great and no noise. Shut her down, take her 20 miles on the trailer, splash her back in the water and death noise. Maybe it is a good thing if it is internal as I had went out on the lake instead of going to the trailer it may have manifested into a really expensive problem if something broke and took out additional items. Probably wouldn't have heard it at speed with wind and exhaust noise.

Reverted water either on shut down pulling onto trailer or when boat was backed into the water after getting gas (my money here). Evidence of water (rust) in all even-bank cylinders but #6 was the lucky one to have enough water to bend the rod. Odd-bank cylinders spotless (no evidence of water/rust). Exhaust manifold/riser pressure tested good. Oil was clear. Y-pipe and tailpipe flappers are prime suspects but I don't have access to boat at the moment.

Spend a little more and put forged slugs and good rods in it. Might as well while it is down.

looks like it took in quite a bit of water.i am to lazy to go back through the thread.what engine and what exhaust.also does it have silent choice?sorry to see that it was not something simple and cheep to fix.

Ouch! Thanks for the update.

496 MAG, Corsa Captains Call, side exit with internal stainless flappers in the tips.

Or starboard side leaned over making your water line higher on that side inwhich reverted water with side exit exhaust. I would measure to make sure you have enough riser height to prevent water reversion.

Boat didn't lean. Engine has 400 + hours. Riser height problems would have shown their face years ago one would think. Builder thinks it has had water pushed up a few times and this time I got unlucky. The last few years the boat only gets taken off and put on the trailer once or twice a year. Otherwise it sits on the lift at the lake. My money is on the y-pipe flapper on the starboard side. That is the most direct route for water to be reverted back up into the engine. And not that it would prevent water from entering, but I did not have the exhaust open when loading or unloading. Hopefully we find a smoking gun and not everything in place.

Engine bored .030 over, new SRP forged slugs and Scat H-beam rods will be installed in all 8 holes.

Even though I mentioned above at 400 hours I would think riser problems would have appeared long ago, I did not discount your input. I've heard from a couple different sources that riser height can be an issue, especially on single engine boats where the engine sits lower in the hull. Below is the only picture I have of the exhaust with the engine in the boat. As you can see, I cannot add the 6" riser extension that is the only one I can find available for the 496. Not enough room overhead. I've got the shop that pulled the engine looking at the y-pipe flappers and the tailpipe flappers for missing parts. If they report back everything is intact, then I would suspect additional riser height might prevent this from happening again. I just wish I had the room to add the extensions.

I would like too see some pics of your manifold / riser height. IMO once you posted that you had side exhaust I would not rule out what I posted for reverting water. Also IMO I think your riser height is too low -

I did not read very many of the posts up here so I might have missed something on top of, but again to add I would like to see manifold / riser height and in relation to waterline height.

Side exhaust can be a real problem with reverting water especially with a boat in rough water conditions that has full gas tanks, along with many people on board and any added equipment ie: batteries, coolers, ice, tools, camping gear, tool boxes and so on.

It is the standard aluminum manifold/stainless riser setup that would have came on any '03 496 Mag. With the boat sitting in the water, the side exit exhaust tips sit above the water line. Even piling a bunch of beer drinkers/hell raisers on the swim platform will not dip the tailpipes into the water. The boat reverted water either when I pulled onto the trailer to go get gas or backing off the trailer returning from getting gas 30 minutes later. Water was dead calm and I was the only person on board. No crazy gear load inside boat. I keep minimal gear/clutter on the boat at all times. Here is a side view of boat. Water line is right about in the middle of the bumped out style line just up from the chine.

My guess would be backing it down the ramp could force feed water up the pipes, especially if it is a steep ramp.

Very weird exhaust , if I'm seeing it correctly. Almost looks like for the exhaust to go to the side exits, is has to turn back .

Maybe a non issue, I don't know, but when I haven't seen something so 'un normal' I just have to state that. LOL.

SB side thru exhaust is extremely popular for the past 15 years with Sea Rays, Crownlines, Cobalts, Bryants and so on with family rec boats. The problem is when a wave hits the side of the boat - and that side of the boat dips down and then hikes back up to the other side can revert water if the manifold riser height is not tall enough. Common problem with this type of install with riser height too low and wave slapping. Also very stern heavy boats the same applies

Common Sea Ray with the common side thru hull exhaust

https://www.youtube.com/watch?v=N98YvYs0-B0

and another hot rod

https://www.youtube.com/watch?v=wEfTrqXaNhk

Correct. The exhaust comes back forward slightly to exit out the side. I've seen more extreme cases of this on other boat brands with side exit. Has work fine for 11 seasons and 400 + hours. That's why I'm hoping we fine broken/missing flappers somewhere. Otherwise it will be a head scratcher. Wish I had access to the boat but it is in storage at the shop that pulled the engine and I'm still not medically cleared to drive after a surgery I had in January Shop owner was supposed to look at Y-pipe and side exits and report back but you know how that goes.

I'm sorry, I am not saying that this has led to water ingestion issues, I'm just saying, excuse the french, this is the most retarded exhaust change of direction I've ever seen. That's all. Just talking out loud.

I don't disagree! It should have been routed out the back. But the way the transom is inset makes it a bit challenging so they went the path of least resistance and stuck it out the sides. Like BUP said, there are tons of different manufactures that run this setup and some come back forward way more dramatically than mine.

Shop finally called back. Both flappers missing in y-pipe. Which is what I figured based on when the boat reverted water. I just didn't see the source being the side exits. At least now I know the source/cause.

Finally! Thanks Ryan (Precision)!!! Hope to have the engine back in the boat in a few days.