Oil change...................MILK! 350 mercruiser

[Rkf63k10]

Well, I haven't even put my new to me 229 in the water yet. Changed the oil and it was milky white. So thinking that maybe it was just water that the previous owner got in the somehow, I went ahead and change out he oil and put a new filter on, ran it and..............same thing. Well it's either blown gasket or cracked block. So I pulled the heads and really didn't find any evidence of a blown head gasket. I looked all over the lifter valley and found no cracks. Heads looked good to. So intake gasket maybe? Don't Know? Intake gasket was a standard steel core and it looks corroded so maybe that was it? I've got a set of Vortec heads that are going on so hopefully there's not something I'm missing. We'll see. Anyone got any more ideas on what could be causing the problem? What do you guys do to flush out the motor while is torn down and still in the boat? Thanks!

p.s. Can someone tell me what the outdrive is. It just says 5.7 on the upper unit. I don't even know what ratio it is.

 

[jumbofordman]

Don't know what kinda shape the exhaust manifolds are in, but every Mercruiser I've had with milky oil has had something wrong with those.

 

[corey331]

Don't know what kinda shape the exhaust manifolds are in, but every Mercruiser I've had with milky oil has had something wrong with those.

You beat me to it. Stock iron exhaust manifolds will rust over time and can leak water into the engine through the exhaust. See if you can have them pressure checked.

On your lower, I would imagine its an Alpha One. There should be a serial number on it somewhere that you can run. That would answer all of your questions.

 

[Rkf63k10]

Well i checked both exhaust manifolds and risers and didn't find any leaks. So I'm still thinking it was a head or intake gasket. This was a Florida boat at one time so it saw salt water, but now all it's going to see is fresh water. Since I have the heads off i decided to go ahead and put a set of Vortec heads on. I'm so OCD though! I start working on one thing and find other things that need addressing! Sun deck had a soft spot in one corner so I removed it and the pad. Pad plywood is rotted on the edges and the corners and the topside of the hatch cover where the "balsa core" is was rotting out as well, so all of that is getting replaced with plywood covered in resin also. The deck pad is still in good shape. Looks like it has been replaced before. So I've got that to do until my heads get here!

 

[Tx91z28]

make sure your oil cooler isn't leaking either

 

[corey331]

make sure your oil cooler isn't leaking either

That's a very good point. Now knowing this was a salt water boat it opens up so much more that it could be. That salt water is some corrosive stuff!! Loves eating away at cast iron and steel from the inside out!!!

 

[Gimme Fuel]

make sure your oil cooler isn't leaking either

The copper tube style oil cooler usually wont let much water into the oil system since the oil system operates at much higher pressures. If that was the case, he would have oil coming from his exhaust when running and it would eventually empty the pan.

 

[Problem Child]

Yes probably a head gasket or exhaust. If you have an Alpha your gear ratio should be 1.47 for the v8. Good luck with it.

 

[Rkf63k10]

Well I'm finally getting around to getting it back together. I went ahead and pulled the outdrive off and serviced it also. Looking at the boat, I think it came with a big block and a bravo. Why it was changed out I don't know. Hopefully when I start it up, no more water in the oil!

 

[SweetK]

I am having a similar problem with my big block but only when I run it hard. I am looking forward to hearing how you make out.

 

[Rkf63k10]

Well I started it up and ran it for a while and..........................................
same thing!!!!!!!

I don't know what to do next. I really didn't do a "real" pressure test on the exhaust manifolds. I did the acetone trick. So before I pull the whole motor out I need to find a place that will pressure test them for me I guess?

 

[Rkf63k10]

Pressure test!!!

Ok, so I figured out a way to pressure test the exhaust manifolds. I found a 2" test plug that expands as you tighten a nut down that fit perfectly. Installed it in the exhaust port. Then over that I installed an old 3" boat exhaust elbow that i capped of one end of. Installed a hose to the exhaust manifold water inlet and one on the riser water inlet and put a Tee in the middle of those two hoses. What I did was fill the exhaust side with water and used air on the water side. If you see bubbles coming out of the exhaust ports then you know there is a problem with that manifold. Well the starboard side failed! so I'm hoping this is where my water is getting into the engine! The acetone test did not show that. I had to put more pressure on it. I'm going to do a pressure test on the water side of the engine also, just to be absolutely sure! Dumb question though, how does the water get into the engine through the exhaust? I figured it would just go on through the exhaust???

 

[Kyain]

Ok, so I figured out a way to pressure test the exhaust manifolds. I found a 2" test plug that expands as you tighten a nut down that fit perfectly. Installed it in the exhaust port. Then over that I installed an old 3" boat exhaust elbow that i capped of one end of. Installed a hose to the exhaust manifold water inlet and one on the riser water inlet and put a Tee in the middle of those two hoses. What I did was fill the exhaust side with water and used air on the water side. If you see bubbles coming out of the exhaust ports then you know there is a problem with that manifold. Well the starboard side failed! so I'm hoping this is where my water is getting into the engine! The acetone test did not show that. I had to put more pressure on it. I'm going to do a pressure test on the water side of the engine also, just to be absolutely sure! Dumb question though, how does the water get into the engine through the exhaust? I figured it would just go on through the exhaust???

everytime you shut off those manifolds are full of water and drain down into the engine.

 

[Kyain]

everytime you shut off those manifolds are full of water and drain down into the engine.

couple that with an exhaust valve being open, water in the cylinder, and heaven forbid it still be there during a compression stroke. Water doesn't like compression

Edit: Holy hell I quoted myself when it should have been an edit.... I have found a new low

 

[Rkf63k10]

everytime you shut off those manifolds are full of water and drain down into the engine.

Well, weird thing is, when i pulled the hose off the bottom of the bad manifold lots of water came out. The good manifold barely had any water in it?

 

[Rkf63k10]

WELL CRAP!

Pressurized the cooling on the engine and water squirted out both sides of the block! So I have a bad block.

Time to start looking for a short block. Wished I could afford and LS swap, but that's not in the budget plus I bought new vortec heads!

Live and learn!

 

[merc245]

Well, thanks for taking us on that 6 week journey to nowhereville!

 

[corey331]

Time to start looking for a short block. Wished I could afford and LS swap

Do it!!! Trust me, you won't regret it. And after you sell what you have, it won't be much more than what you are going to do!!

 

[Rkf63k10]

Do it!!! Trust me, you won't regret it. And after you sell what you have, it won't be much more than what you are going to do!!

If I went that route, who makes the exhaust manifolds? Do I go carb or stay fuel injected? Will a ls mate up to the bell housing?

 

[corey331]

If I went that route, who makes the exhaust manifolds? Do I go carb or stay fuel injected? Will a ls mate up to the bell housing?

There are a few companies that make manifolds now. I can't think of them off the top of my head but I know cooperider found some that were reasonably priced. Around $700-800 a set. I went carb on my LS swap because it was cheaper and simpler. But people have done EFI. If I ever boost my motor, it'll probably get Holley EFI. But the carb ignition I used was from Daytona Sensors, it's called LS Smart Spark. It's so simple it's ridiculous. You hook up power and ground to it, then plug in each bank of coil packs, a cam sensor and a crank sensor. That's it. It's a million times more user friendly than the MSD ignition and it was cheaper. Yes a Merc bell housing bolts right to the LS motor. There is one bolt (upper right) that doesn't go. But the other 5 line right up. And your coupler will bolt right onto a manual flywheel out of a Camaro/Firebird with the locator pins knocked out. I also got some billet motor mount adapters off Amazon for $30 that will let you use the stock Merc motor mounts. Since you have an Alpha One drive, you won't have the headache I had of trying to mount a sea water pump.

It might cost you a little more overall to swap an LS into the boat, but you will also be a lot of horsepower ahead of a built small block. And you will be building on a better platform if you want to make more power in the future. Heck, mine makes just shy of 600hp and I'm still running a stock casting cylinder head!! I have a feeling if I dyno again after she's broken in, I'll be at that 600 hp mark.