Water+oil milkshake. Leak down results

[Undertow113]

Hey guys, this forum has really helped me out in the past and I’m in a bad milky situation now.
I have a 94 mercruiser 4.3lx. I went to recommission everything for the summer and after a couple min on the muffs I noticed milkshake sprayed all over top of motor. I shut it off and drained about 2 ga of water out of the oil pan. The motor was flushed with antifreeze while winterizing but nothing drained from block or manifolds.
I did notice that both exhaust manifolds are cracked along the outside. I removed the thermo housing and rigged up a pressure test rig to try to pinpoint where exactly this thing is leaking. After capping off the water pump hose and pressuring, I am getting air out of my valve covers. Any ideas on where or what may be cracked to be getting air here. I’m getting air out of both sides. Any input I would appreciate. Thanks!

 

[Bt Doctur]

the cracks are in the valley just above the lifters, block is junk.
Next time winterize it correctly to prevent a repeat

 

[tpenfield]

As stated, at this point, it really does not matter . . . the block, manifolds, etc are junk. An expensive lesson on winterization techniques.

You should be able to get a new 4.3 long block and a set of exhaust manifolds for not too much $$$$

 

[Scott Danforth]

you have to drain everything prior to ever adding anti-freeze

with your motor being a 1994, its right in the middle of the 1992-1995 family of 4.3's

to make life easier on you, find a 92-95 vintage motor and have it rebuilt (doubt you could find a low mileage motor)

here is some reading. https://forums.iboats.com/forum/eng...history-of-the-4-3-liter-with-casting-numbers

 

[gergAlicious]

I found decent long block pricing at ~$2k for a 4.3.

I ‘think’ I paid about $200 per exhaust manifold. My risers were fine.

My block pressure tested fine so I just went with heads and manifolds. Also replaced all core plugs, starter, circulation pump, plugs, wires & cap. Chose to add the remote oil filter option also.

Good luck!!

 

[harringtondav]

Yep with Scott Danforth . Flushing w/antifreeze doesn't do any good unless you let it come to full operating temp, and flush w/antifreeze for a looong time until the block is full of pure, or at least 50/50 antifreeze. If you are anal, flush w/muffs, drain every thing per the manual. Button it back up and add antifreeze through the pipe plug at the left of the thermostat hsg. until it pours out the exhaust.

I was once this anal, until I added the antifreeze one beer over the line thru the intake manifold plug. Darn engine wouldn't turn over in the spring, until I removed the plugs and had a six jet antifreeze fountain in the engine compartment. I squeezed by that bonehead by changing the oil w/cheap Advance 40 wt, running the engine till at temp, and draining it - twice before adding spec. oil. I was lucky. No oil consumption or engine problems for 15 yrs since. Now I drain the water in the fall and walk away.

 

[Rick Stephens]

Like harringtondav, I am of the philosophy that air doesn't freeze. I live in northern Idaho and I like to fish right up into where the days are cold and the nights colder yet. So I have the drain routine down to a few minute job. When I bring the boat back, I hook up to the muffs, warm it up, shut it down and pull the drains and disconnect the big hose from below the water pump. Total job is done in about 10 minutes. I do that job after every use of the boat during the fall so I don't freeze something. On a really cold day at the lake, I'll do the 10 minute drain thing right on the empty boat ramp when I pull the boat out at the end of that day. Never used antifreeze, never will.

 

[gergAlicious]

Rick - I have a drain point in the bottom of the elbow of that large water pump to thermostat hose. Would that negate me from having to remove the large hose at the bottom?

I am NEVER pulling this engine again due to my negligence!

 

[Rick Stephens]

Rick - I have a drain point in the bottom of the elbow of that large water pump to thermostat hose. Would that negate me from having to remove the large hose at the bottom?

I am NEVER pulling this engine again due to my negligence!

That's pretty cool! I never even considered that. I did add a drain beside the power steering oil cooler so I wouldn't have to disconnect the 'in' line from the cooler. Never even thought about a drain for the water pump. That one is really easy to get to anyway.

 

[gergAlicious]

Here it is - I presume it was factory on this Chaparral

 

[Bondo]

I have a drain point in the bottom of the elbow of that large water pump to thermostat hose. Would that negate me from having to remove the large hose at the bottom?

Ayuh,..... I pull the bottom end of that hose off every drainin',..... Yer drain oughta do the same job,....

'course, that only drains the quart or so that lives in the circulatin' water pump,....

I only discovered the need to drain that hose after goin' fishin' 1 cold mornin',....
Backed the boat in bustin' the ice outa the way with the wagon, then hopped into the barge before unhookin' to warm it at the dock, while parkin',.....
A couple pumps of the throttle, 'n the motor came to life, with a helacious screamin' belt,....
Shut it off, looked it over, the circulatin' pump was seized,.....
Thawed it out with a torch, went fishin', 'n started drainin' the hose at every drainin',.....

Had a very long very involved discussion with Don S 'bout it,....
He was of the mind that it was Unnecessary to pull that hose, as he'd never had such a problem, 'n never had a froze busted circulatin' pump,.....
I was of the mind that, Ya, ya don't have to drain it, so long as ya don't wanta start the ,motor when it's still Cold out,.....
The tin backin' plate flexes, which is why the housin's don't freeze bust,....
Still gotta be tough on the seal,....

Anyways,.... After awhile Don went, 'n pulled that hose, After he drained a system, the way he'd Always done it,.....

I would have Loved to have been a bilge fly, 'n seen his face, when he got Wet, from the quart or so of water hit him,....

 

[thumpar]

I have always pulled that hose because I thought it was part of it. Just by looking at the shape you can see that water is going to be in there. It may not be damaging but I pull it. I also pull both hoses on the impeller housing on my Bravo.

 

[porscheguy]

That drain plug by the circulation pump is not chaparral, it’s mercruiser. I’ve got it on mine. They probably introduced it in the late 90s. That is one of the five drain plugs. You need to pull all 5 and give each the wire treatment. Failure to do so is either a result of lacking knowledge, or laziness.

 

[Lou C]

Why they should all be closed cooled. At least a half system. Even in fresh water you get a layer of rust inside that eventually interferes with heat transfer. When I changed out my old heads last summer I noticed cooler running.

 

[Undertow113]

Thanks for all the inputs guys. I’ve been pricing out some reman long blocks, manifolds, gaskets etc. I have a lead on a complete used motor but I’m leaning towards just starting over new. I definitely don’t want to do all this over again. Expensive lesson learned that’s for sure! Especially considering I darn near rebuilt the entire outdrive just last year. I guess it’s time to Bust Out Another Thousand...or 2. :uncomfortableness:

 

[cableguy1979]

Before you go out and buy a new engine why dont you pull that one apart? If you have a busted exhaust manifold air can get back through the exhaust valve guide to the valve cover. Just saying I would check it first. These guys are much more knowledgeable then me but I live by the "trust but verify" rule. beside this may be something that could be fixed.

 

[Bt Doctur]

a quick test is remove the T stat housing and pour water in the intake, if it goes down quickly you hace a crack(s)