checking antifreeze level Mercruiser 165

marvinjansen

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I feel really ignorant, can't find where to add or check the antifreeze level on recently acquired 1973 Aristocraft with Mercruiser 165, a Chevy 250cid straight 6 cylinder. Also, where do you check the tilt hydraulic fluid? I saw a pic of a 4 cyl that had a cap on the manifold, but there is none in sight on this one. I see a small hose going out the stern, what's this for?
 

kilowatts

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Re: checking antifreeze level Mercruiser 165

Hi Guys:

Is your engine raw or fresh water cooled? If raw, then no antifreeze. If fresh, then antifreeze in 1/2 the heat exchanger, the engine block and manifold.

kilowatts
 

marvinjansen

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Re: checking antifreeze level Mercruiser 165

I am not sure if it is just cooled by "sea water", but there is a petcock on the manifold that when opened ran green antifreeze. Either winterized or I suspect a separate coolant for the engine. Thought maybe someone had the same engine and setup.
 

Bondo

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Re: checking antifreeze level Mercruiser 165

or I suspect a separate coolant for the engine.

Ayuh,... I doubt it,... Sounds like a raw water system...

That's what the little hose you ask about is,....
Raw water from the impeller in the lower unit...
 

dubs283

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Re: checking antifreeze level Mercruiser 165

mercruiser 165, 6 cyl was not factory closed cooled

you have not run this engine either on muffs or in the water??

if you had, i bet pure water would come out the drain
 

marvinjansen

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Re: checking antifreeze level Mercruiser 165

I haven't run it yet, was afraid the impeller would come apart and clog up things. I have been replacing broken trim cylinders too. So you are saying it
cools with raw water, no antifreeze. The chevy 250 has a water pump too, does it have 2 pumps, one in the foot and the engine one too?
Think I am going to put it in some water or use the muffs and see what happens. After running in water do you need to put in antifreeze if the weather goes below freezing?
 

marvinjansen

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Re: checking antifreeze level Mercruiser 165

Hi Guys:

Is your engine raw or fresh water cooled? If raw, then no antifreeze. If fresh, then antifreeze in 1/2 the heat exchanger, the engine block and manifold.

kilowatts

I watched your u tube and you have a nice sounding 165. Is yours "fresh" now? Is that better?
 

ziggy

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Re: checking antifreeze level Mercruiser 165

if the engine is fwc, the heat exchanger would be below the manifold on the port side. the hose from the tstat housing would go to the heat exchanger, and a hose from the circulating pump would go to the heat exchanger.

the water hose from the stern drive would go to the heat exchanger and a a hose would be going from the heat exchanger to the manifold.

my nineteen don't have fwc. it's rwc.

the long hose coming from the stern drive goes to the tstat housing, a hose goes from the tstat housing to the manifold. a large hose goes from the tstat housing to the circulating pump.
this is the typical set up i've seen for most 165hp.

did ya ever get a service manual. ya gotta have one to be able to work on yer stuff.. there's pics of what i just described in the service manual.... ;)

I haven't run it yet, was afraid the impeller would come apart and clog up things.
ya might as well R&R the impeller in the drive now. it's a yearly inspection item. i replace mine ever year as i feel they take zero abuse. if they(the sea water impeller) disintegrate from abuse, the ramifications aren't very good.
So you are saying it
cools with raw water, no antifreeze.
most likely, but we can't see it to be sure. that's the way mine is.. no anti freeze..
The chevy 250 has a water pump too, does it have 2 pumps, one in the foot and the engine one too?
yes, the sea water pick up impeller is in the lower part of the drive. the circulation pump is on the ft. of the engine. the circulation pump generally don't have issues.
After running in water do you need to put in antifreeze if the weather goes below freezing?
ya don't have to, but. ya do have to drain the water out of the cooling system. ALL OF THE WATER. ya can't leave any inside the engine or the manifold or the drive. the drive will self drain by gravity if you lower the drive all the way in/down. you have to manually drain the water out of the block and manifold. my block has a t valve to drain. the manifold has a plug. if ya got a plug. after ya remove it. stick a wire probe in the hole and be sure it's a free and clear hole that really has drained all the water out of it.
fwiw. i drain into a folgers coffee can. 27.8oz can. i get one full coffee can of water out of my manifold . i get three full cans out of the block. this is typical for my rig. yours sounds similar. you'll have to decide whats right for you though. for freezing temps, the key is. ALL THE WATER OUT OF THE COOLING SYSTEM.
ya can do anti freeze if ya want. i did anti freeze the last 2 years. this year i'm going with air.. no anti freeze

mercruiser 165, 6 cyl was not factory closed cooled
are ya sure. there's reference to fwc system in s/m 2 that i use for my 165hp.. i was looking at the pic for a 165hp in s/m 2 for my description that i just gave the op..
 

marvinjansen

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Re: checking antifreeze level Mercruiser 165

Thanks for explanation, now I am not so ignorant. I have the same system as Ziggy I am sure. I will download sm #2 and learn more.
I think in a previous post I read that the impeller is easiest changed with the drive off the boat. Does anyone do it on the boat and how long a job is it?
 

ziggy

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Re: checking antifreeze level Mercruiser 165

I think in a previous post I read that the impeller is easiest changed with the drive off the boat. Does anyone do it on the boat and how long a job is it?
it's not changing the impeller thats so hard. it's putting the lower back on the upper that's a drag when the upper is still attached to the boat. + there's yearly pm ya should do that requires the drive to be pulled. so ya might as well kill two birds with one stone so to speak..

i've done the deed with the upper still attached. all it does is wear me out, make me cuss and frustrate me when i'm putting the lower back on..
my drive is removed right now and in the basement awaiting it's yearly service..
 

ziggy

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Re: checking antifreeze level Mercruiser 165

IMG_0624.jpg


a pic of no heat exchanger.

the long hose is what comes from the drive and leads to the tstat housing.

ya can see the t drain for my block at the back bottom of the block. the brass thing. the manifold drain plug is right above that on the aft bottom of the manifold..
 

marvinjansen

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Re: checking antifreeze level Mercruiser 165

Ziggy, The pic is the same as mine. My Aristocraft 19 was made on June 21, 1973 according to Scott. I am so looking forward to cruising up Lake Tuscaloosa.
 

ziggy

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Re: checking antifreeze level Mercruiser 165

check yer pm marvinjansen...
 

stonyloam

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Re: checking antifreeze level Mercruiser 165

Make sure you completely flush any spilled antifreeze off of the driveway when you run it. The green antifreeze is deadly to pets, and they like the taste. Good luck.
 

stonyloam

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Re: checking antifreeze level Mercruiser 165

The "165" 4 cylinder engine that you referred to with the tank and radiator cap is the 3.7 L 470 engine and does have a closed cooling system with antifreeze and a heat exchanger, the 6 cylinder "165" is a Chevy straight six and is a completely different engine. It is most likely the antifreeze you saw coming out was there for winterization purposes. In the future if you decide to use antifreeze for winterization it would be best to use the non toxic RV (pink) antifreeze.
 

Wills03

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Re: checking antifreeze level Mercruiser 165

Here is a picture of the closed cooling system from my 1976 operators manual which covers the 120 & 140 4 cyl. and the 165 6 cyl.
 

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kilowatts

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Re: checking antifreeze level Mercruiser 165

Hi Guys:
Yeah, Ziggy's right. Just do what he said and you should be OK.
My inline six has a San Juan Engineering aftermarket system which most likely was installed from new. They're manufactured in Bellingham, WA so lots of MCM engines in this area have them as a matter of choice.
kilowatts
 

marvinjansen

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Re: checking antifreeze level Mercruiser 165

I like draining the water out and no antifreeze in my mc165. I now open the petcock on the block, pull the plug in the bottom of the manifold, and remove the big "U" hose from the water pump and feel all the water is out. I can run it during the day and drain it when quiting for the nite when it will be below 32. Easy. I bet some engines have pockets and require antifreeze, glad my old Chevy inline 6 isn't one of them.
 

Don S

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Re: checking antifreeze level Mercruiser 165

I don't know if you have it or not, but here is a link to the OEM service manual for you engine and drive. You really need to spend some time reading it. It would answer a lot of the questions you have been coming up with your own ideas on, and then posting about.

http://www.4shared.com/document/ozc1_97A/Service_Manual_01.html
 
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