5.7 v8 mercruiser

johnson 110

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Question, I want to drain the block of all water, I see two block drains and two exhaust manifold drains. Is this all I need to drain to get the water out first, I next want to pour antifreeze in the hose for the manifolds and pour antifreeze in the thermostat and be done! Just want to make sure if I got all the drain plugs on the engine! Thanks for any replys.
 

Don S

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Re: 5.7 v8 mercruiser

Pull the big hose off the water pump and drain it too.
 

180shabah

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Re: 5.7 v8 mercruiser

And don't forget to seperate the hose at the P/S cooler(unless yours has the drain plug in it).
 

johnson 110

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Re: 5.7 v8 mercruiser

This hose for the power steering pump, Is it right below the pump? Thanks for the advice!
 

Don S

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Re: 5.7 v8 mercruiser

The water hose on the power steering COOLER, not the pump. The oil cooler has water going thru it to cool the oil. If you don't drain it, a freeze will break the cooler.
 

sundowner205

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Re: 5.7 v8 mercruiser

Those 4 plugs are the only ones on the block. Just be sure to do what Don suggested with the P/S cooler.

Where are you at on LI?
 

hondon

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Re: 5.7 v8 mercruiser

Mercrusier has alot of different formats with that 5.7.You may also have a fuel cooler and seawater pump that need to be drained.You will also need to drain the circ pump.Narrow it down a little more.Sterndrive,direct drive,vdrive,carb,tbi,mpi mag or black scorpion,all have different formats and change with vintage as well.
 

johnson 110

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Re: 5.7 v8 mercruiser

The mercruiser that I have is a 1995 Alpha 1 the boat is a 24 chapperral that we purchased this year from some friends that moved down south. This is my first I/O that I own, I always owned outboards with my boats in the past, The boat just had 3k worth of work done to it by a marina with the previous owner. He told me that the heads, manifolds, risers were all replaced, The owner did not know ANYTHING about engines, he had the boat only 3 seasons and paid 14k for it from a dealer right here in Amityville NY. I am not a big fan of this engine setup raw water cooled but we got a very good deal on the boat so I figured I would give it a go, The engine/boats runs very nice, however the skeg broke off this season so that will have to be repaired!
Thanks for all the advice here on the board, I think this forum is the best!
 

littlebookworm

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Re: 5.7 v8 mercruiser

The answers you've gotten pretty much cover the key points. I suggest you read the sticky at the top of the forum for a few extra pointers. I'd add: grease all the fittings you see, spray wd40 on the engine to minimize rust, winterize your cabin water system (if you have one), clean the boat and the bilge, tilt your cushions up to minimize mildew. Good luck. Hy
 

johnson 110

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Re: 5.7 v8 mercruiser

Thanks for the advice, I pulled the two block drains and stuck an awl in there and water did comeout also drained the manifolds with the drain screws and pulled off the power steering hose coller from the front and some water out! Ipuuled the hose off the water pump too in fact I puulled most of the hoses off! Should I take off the thermostat and dump some antifreeze in or can I just leave the block and manifolds just the way they are? Thanks again
 

sundowner205

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Re: 5.7 v8 mercruiser

Thanks for the advice, I pulled the two block drains and stuck an awl in there and water did comeout also drained the manifolds with the drain screws and pulled off the power steering hose coller from the front and some water out! Ipuuled the hose off the water pump too in fact I puulled most of the hoses off! Should I take off the thermostat and dump some antifreeze in or can I just leave the block and manifolds just the way they are? Thanks again

If you are confident that you drained all the water, anit-freeze is not necessary, however some of us add it for peace of mind. I personally do, however, as you know the passed few winters here have not been that bad.

Remove the thermostat and fill the block completely. You also want to remove the hoses going from the thermostat housing to the exhaust manifiolds and pour some anti-freeze down them, as well as the large hose from the water pump.

Beautiful day here!, BTW........leaving the office early to go boating!
 

Bondo

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Re: 5.7 v8 mercruiser

or can I just leave the block and manifolds just the way they are?

Ayuh,....

Why Waste the money on antifreeze,... It's Not at all Necessary...

Air just Doesn't Freeze....;)
 

johnson 110

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Re: 5.7 v8 mercruiser

How much antifreeze will the block take by adding it through the thermostat?
 

180shabah

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Re: 5.7 v8 mercruiser

Air just Doesn't Freeze....;)

I saw on TV that Al Gore said that because we still use boats and lawnmowers adn drive big trucks, this year it just might get cold enough for air to freeze......
 

180shabah

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Re: 5.7 v8 mercruiser

....But if we each donate $100 to a carbon offfseting program, then he can personally guarantee warm sunny skies all winter long...
 

chiefalen

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Re: 5.7 v8 mercruiser

I personally prefer corrosion pro vs wd 40.

I also spray all the connections with it also.

Not pb blaster, only for bolts that are rusted.
 

Bondo

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Re: 5.7 v8 mercruiser

Quote:
Originally Posted by Bond-o
Air just Doesn't Freeze....

I saw on TV that Al Gore said that because we still use boats and lawnmowers adn drive big trucks, this year it just might get cold enough for air to freeze......

Ayuh,...

I thought that moron was saying that We'll be using our boats year round, because of Global Warming,..??
 
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