1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with oil

[spoilsofwar]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Worn valve seals, they leak a bit of oil and it gets sucked down the valve stem and into the cylinder on the intake stroke.

 

[wrench 3]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

I'm wondering if it's fogging oil and thats as far as it got. Seeing as how good a job they did on the rest of the winterizing. Any way, the valve seals can be replaced with the engine in the boat, no problem.

 

[Bondo]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Ayuh,.... At this point, it's moot,...

Pressurize that thing, 'n lets see if the Block is Cracked,... or not,...

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Ayuh,.... At this point, it's moot,...

Pressurize that thing, 'n lets see if the Block is Cracked,... or not,...

did that last weekend, here is the comment


I did some more troubleshooting today...

The core plug looked really good ( will purchase a new one), but I cleaned the edge of the brass core plug aka "freeze plug" with my buffer, and cleaned up the rust that was around inside rim of the core hole in the block.

I then re-installed the core plug back into the core hole in the block,( *****just temporary, so I can air pressure test the block*****) using some gasket sealer on the edge of the freeze plug.

I then setup to air pressure test the cooling passages in the block...with oil pan drain plug removed

I hooked up my hoses, clamps, pressure gauge, ect, induced 20psi into the cooling system. I immediately saw the pressure gauge start to drop by lb , "Oh crap!!! maybe I had an internal cracked block", I really said a few choice words, other than " Oh Crap" .

I then got my bottle of soapy water, re- pressurized the system again to 20psi, and started spraying all my hose connections that had clamps. as the pressure was dropping I located some major leaks around the hoses, so I tightened up the clamps some more.

I got all the clamps tightened, sprayed soapy water on them again, no more bubbles

I induced 20psi again into the cooling system......it held pressure for 2+hours, maybe even longer. I did not unhook the air until I got up all my stuff that I had strolled all over the place today. The last thing I put up was that air hose probably about 35 more minutes later

so IMO I feel like my block does not have a crack...that is IMO on the block only

my next test will be a cylinder leak down compression test

I would appreciate opinions good or bad, they all help

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Ayuh,.... It's probably the standard Chevy, 1, 5/8" core plug, just be sure to buy it in brass,....
Measure it to be sure,...
No reason to have a Mercruiser number for it, it's a standard brass core plug,...

Or, just beat that 1 back it,....

I did beat it back in, after I cleaned it up.......

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Worn valve seals, they leak a bit of oil and it gets sucked down the valve stem and into the cylinder on the intake stroke.

I was thinking the same thing...

I have decided to remove the head at this point, take a look at the head, gasket and cylinder walls

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

update!
I got the head off this evening, after letting the head bolts soak in penetrating oil over night. I had two bolts that were rusted bad on the external threads, and shaft. it took a while to get them loose with an 1/2" air impact

Then I had to use a blade to wedge between the head, and block just to break it free from the block
I would appreciate any opinions on the head, and block, thanks!

I will be checking the head, and block cylinder walls for internal cracks. If i find none, I will then flip the block, and remove the pan, then check for internal cracks

this pic I outlined in red where I had to use a scrape to wedge between the head, and block to separate the two

Here is the block

 

[wrench 3]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

If you did any damage to the sealing surfaces when you wedged the head off, use a file and take off any high spots. As long as the damage is outside of the fire ring (the crimped on metal part of the gasket) it shouldn't cause any problems.
The cylinders don't usually crack from freezing because their shape gives them a lot of strength.
There is a spray on crack check that is usually used on non-ferrous metals, that you could use if any thing looks suspicious.

 

[fishrdan]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

I don't see any issues with the block/head, but can't make out much detail due to the angle of the pics. Turn over the engine so you can see each cylinder. Also need to clean off the gaskets as they could be hiding something.

NOW, that manifold.................. Is that JB Weld on the head side? :facepalm: If it's JB Weld you need to carefully inspect and acetone test the manifold, fill it with acetone and see if it leaks out anywhere. If that manifold leaks internally, it's a sure way to get water into the engine.

Myself, I would not us a manifold that's been JB Welded, or a manifold that's been cracked. Time for the scrap pile.

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

I don't see any issues with the block/head, but can't make out much detail due to the angle of the pics. Turn over the engine so you can see each cylinder. Also need to clean off the gaskets as they could be hiding something.

NOW, that manifold.................. Is that JB Weld on the head side? :facepalm: If it's JB Weld you need to carefully inspect and acetone test the manifold, fill it with acetone and see if it leaks out anywhere. If that manifold leaks internally, it's a sure way to get water into the engine.

Myself, I would not us a manifold that's been JB Welded, or a manifold that's been cracked. Time for the scrap pile.

I am going to put the engine on the stand on Sunday, then get to work removing the old head gasket material, and inspecting

I did test the manifold with water, let it set for 3 days, no leaks to the inside or outside thus far, not sure about the acetone test?

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Well, I thought I would update this thread of what I found once mounted the engine on the stand, and removed the pan...

I saw a vary clean engine, with only some minor rust spots on some of the crankshaft counterweights, and block, kinda just random areas. I had a high power light, and looked around inside of the block, in every nook, and cranny, turned the engine to several different angles, so as to get a better look into some of the hard to see areas, for about 1 1/2 hours.

I then went across the street to my neighbors home, and asked if he wouldn't mind looking at it with me, for a second opinion ( he used to own a Marine Dealership for years, in Florida, serviced may engines, so I value his opinion)

I know that I need to find out what he thought, he had been back and forth, on his opinion, like I was....maybe internal crack block, maybe not a internal cracked block, possible a partially submerged engine...

Well he looked inside it, and looked inside it, and looked inside it...and I quote
" I see no evidence of an internal cracked block, just vary minor rust on the crank counterweights, and block, in random areas, which just wiped off with his finger, it all looks brand new!" He said " If I were you I would clean the bottom end up a bit, get as much of the milky out of her, turn her upright, put it all back together, do some valve work,and start her up" he also believes partial submersion, but not for a long time, or the bottom end would have rusted up more than it is, he thinks. I am not sure either bout that....we will never know the full story of what happened to this engine, other than freezing at some point

as usual, I appreciate the comments, good or bad....
just a few pics

 

[fishrdan]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Sounds like you got solid advice from your neighbor as that shortblock looks pretty clean inside. The head doesn't look bad, but since you have everything torn down and there's evidence of a leaking valve seal, I'd have the head rebuilt and reassemble everything.

Did you keep track of which which cam lobe each lifter was removed from, so the lifters go back in the same bore they were removed from?

not sure about the acetone test?

Acetone will leak through small cracks that water will not.

Something to do with water having "surface tension" that keeps it from leaking through small cracks and making it a poor substance for "crack checking". IE: water could bridge across a crack that acetone will leak through.

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Sounds like you got solid advice from your neighbor as that shortblock looks pretty clean inside. The head doesn't look bad, but since you have everything torn down and there's evidence of a leaking valve seal, I'd have the head rebuilt and reassemble everything.

Did you keep track of which which cam lobe each lifter was removed from, so the lifters go back in the same bore they were removed from?





Acetone will leak through small cracks that water will not.

Something to do with water having "surface tension" that keeps it from leaking through small cracks and making it a poor substance for "crack checking". IE: water could bridge across a crack that acetone will leak through.

I feel like I got some good advice, and this will work out, maybe. I will take the head to be checked out. I did ensure that the rockers, lifters, and push rods all were labeled per the correct cylinder. I did also order the head gasket, and manifold gasket kit.

Now are these head bolts TTY or can I reuse them. I had a Toyota 4runner with a 3.0 that I replaced the head gasket, and the TTY head bolts had to be trashed, could not reuse them.

The acetone test I will keep in mind, and will possibly try that

Forward we go....

 

[fishrdan]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Head bolts are OK for re-use, not TTY.

Run a tap down each head bolt hole to clean the threads of rust and old sealant, wire brush the head bolt threads, then use Permatex Aviation Sealant to seal the head bolts. I put a little sealant in/on the block threads, then dip each head bolt to cover the threads and blot off the excess sealant.

Be sure to use the graphite/metalized manifold and riser gaskets as they are far superior to paper gaskets.

 

[wrench 3]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Considering that you would have to remove the engine again if that rear frost plug fails, not to mention stranding you on the water, I'd install a new one. They crush when you install them and might not fit as tight the second time around.

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Considering that you would have to remove the engine again if that rear frost plug fails, not to mention stranding you on the water, I'd install a new one. They crush when you install them and might not fit as tight the second time around.

thanks for the info
I plan to put the engine back together, test run it with engine out, and old expansion plug still in the block. If the engine will start up, and run, and runs well. I will replace that plug with a new on before installing that engne, for sure!

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

searching info on,
how to wire this engine to run outside the boat.

I would appreciate any key words to use to search for this info.

thanks!

 

[wrench 3]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

searching info on,
how to wire this engine to run outside the boat.

I would appreciate any key words to use to search for this info.

thanks!

If you go to http://www.boatfix.com/merc/Techbk/94/94hg4d.pdf the wiring for your engine is on page 4D-2. To keep it running you need power up the purple wire going to the ignition coil. This can be done at the shift interrupter switch (item #2) from any battery pos. Or by crossing terminals 5 &6 at the main harness plug. To crank it over just temporarily cross the two large terminals at the starter relay (item #6).

 

[wrench 3]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

BTW While looking for your information I discovered that OF023890 is your correct serial number. OF023390 comes up as a 7.4L.

 

[saltybutwet]

Re: 1993 Mercruiser 3.0 new to me, with major problems, Not Running, Water mixed with

Thanks to all, who has helped me with this project. I apperciate the advice, and your willingness to provide correct information.

Thanks again