Mercruiser 4.3 vortec, but older only found 4 freeze plugs

sickwilly

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The father of one of my son's friends had a bad car wreck and has been in the ICU for nearly 3 weeks. We have a freeze warning tonight, so yesterday I went over to tend to his boat. He has a maybe late 80's or early 90's mercruiser 4.3, with vortec heads. However, unlike my 2004 version of the 4.3, I could only fine the freeze plugs under the exhaust manifolds and on the sides of the block (4), whereas I also have one on the front, coming off the water pump.

Did I miss one?

I don't have the serial number. I can further describe the mercruiser engine though. it has the larger rectangular flame arrestor on top, and the power steering cooler is actually under the front side of the engine, versus on the rear like mine.

I tried to get a hose off the water pump but was unsuccessful. I could not get leverage in the tight compartment of the engine.

I did, though, hit the safety cut off switch and turn it over several times, hoping to move any remaining water out that did not drain.

OK, any thoughts on if there was a 5th plug that I missed?

Thanks.
 

alldodge

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

The 5th plug is on the bottom of the power steering cooler. It takes a 7/16 wrench to remove the plug. If you can remove the hose from the thermostat housing you could poor a small amount of antifreeze down it to mix with any water left behind.
 

sickwilly

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

Thank you! I did not feel under the power steering cooler. It is going to be a hope and pray night, then as I can't get back over there for a day or so. I hope the weatherman is wrong!

At least it won't be his block that cracks.
 

cliffblue

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

When in doubt, stick a shop light in there till you're sure.
 

Bondo

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

Thank you! I did not feel under the power steering cooler. It is going to be a hope and pray night, then as I can't get back over there for a day or so. I hope the weatherman is wrong!

At least it won't be his block that cracks.

Ayuh,.... Get yerself a Hose Pick,.... It's like an Ice Pick, only with a bent needle,...

It makes it Easy to slip under the hose, 'n break the seal on whatever it's hooked too,....

For yer Bud's motor, go back over, 'n pull either of the Big hoses off the P/S Cooler, 'n also the Big hose off the circulatin' water pump,...

So long as ya poked the crud outa the drains ya found, it'll be Good to go through the winter season,...
 

sickwilly

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

Will get a hose pick. Thanks!
 

Volphin

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

We were at 39 degrees this am. Brrr! Did it reach freezing in Mid TN? Agree with a 100w shop light idea... keeps things warm enough on borderline nights.
 

sickwilly

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

The boat is sitting uncovered out in the yard. Will a shot light still help?

It is supposed to hit 31 tonight in Mid TN.
 

alldodge

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Re: Mercruiser 4.3 vortec, but older only found 4 freeze plugs

The shop light should work, put it under the engine. I'm in south KY and it will get cold but will not stay there so you should be fine. Ice may start to form but should not get solid enough to break things. Only caveat is the power steering cooler, it is thin walled. Still think it will be OK but put the light under it, and keep the engine hatch closed.
 
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