SB

iTrader: (1)

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

BUP

iTrader: (9)

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.

Knot 4 Me

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.

Drew555

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

BUP

iTrader: (9)

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

BUP

iTrader: (9)

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.

Drew555

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

Knot 4 Me

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.

BUP

iTrader: (9)

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

turbom700

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