4.3l mercruiser with steam from vent lines

[81 Checkmate]

Re: 4.3l mercruiser with steam from vent lines

Just me..... And what im thinking... No expert, But your orange plugs look like they are rusted or have had water on them to turn them that color.

Water and bare steel mixed = Rust

I would pull all the plugs and turn over the motor and see if water squirts out........ Then if so. squirt some oil in all cyclinders, turn over to lube it. Then put plugs back in and look into where the water is coming from.

Yer getting water from somwhere...Hope its not a cracked block.

Good Luck!

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Just picked up some new oil and riser gaskets. Wish me luck. Looking at the manual I see they only sold me the exhaust elbow/riser gaskets. Probably should be doing the lower gasket too...the one between the riser and the manifold. Guess I should have checked the manual before I went down they and asked for the gaskets! Can't see to get anything right these days!

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Should I take the manifold off too?

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Hi Checkmate,
I think you are bang on - I took a few pics. Seem they used some sort of liquid gasket with the oem gasket - should I do the same? Would you did deeper and replace the manifold gasket too? It is a white gasket material - would they have made this gasket or are some of them white?
Manifold


Riser

Inside Riser

White manifold gasket. Is this supposed to be a steel gasket???


I have to go back and the the right gasket tomorrow. The one I picked up today doesn't match up.

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

One more picture looking down inside the manifold - A assume the water should only be in the four smaller ports. I did remove the supply line before I separated the riser from the manifold.

 

[81 Checkmate]

Re: 4.3l mercruiser with steam from vent lines

Doc - Looks you may have found the problem.

Do not use a sealer.....Use only OEM Gaskets only.....not the green ones.

If all posible the best thing would be to have your manifolds and risers conections decked (Machined) for a flat sealing surface.

If not in the budget clean the surface very good and flat.

Good Luck!

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Thanks for getting back to me Checkmate! I was beginning to freak myself out with the "what ifs" of cracked blocks etc. It almost looks like too much water is getting in though based on the puddle inside the manifold.

I am going to go back outside and grab the riser again - in the picture I see what looks to be some sort of resin in the elbow. Can't imagine its cracked...riser and manifold look to be in good shape to my uneducated eye.

Anyone have advice to offer about that white gasket? I thought it should be metal. Both sides are the same. I suppose this really has nothing to do with water in the oil and can wait. I haven't pulled the port side yet - the plugs were dry. Maybe a winter project.

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Couldn't sleep. Got back up out of bed at 11:30 and pulled the manifold off. Will figure out a way to pressure test tomorrow.Probably should have pressure tested the cooling system before I took it apart.

Feel much better - reasonably confident now that the riser gasket had failed based on rust "trail" starting below the joint. Exhaust valves look ok. I can rest now and I'll see who i can rope into helping me re install everything this weekend. I may try to do a cold oil change tomorrow to get some of the milky crap and put some oil down the cylinders. Looks like I'll be doing a couple oil changes anyway.

 

[81 Checkmate]

Re: 4.3l mercruiser with steam from vent lines

Doc - Looks like you are on the edge of the seat!

Me personaly i would go ahead and take the other side apart! Just for the sake of not getting any sleep....... You are this far into the game why not do a complete job. Take them to a mach shop and have the mating sufaces cleaned up for a good seal.

Then buy a case of Bud and invite your helper over for the weekend.....

Good Luck!

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

I'd like to get the milky oil out and fill her up with new oil while I'm waiting for time to finish the repair. I should have done this before I took the manifold off.

Is it okay for me to add a little diesel to the oil (say a quart) to thin it a bit and turn it over on the starter with the manifold off? I assume I should cap the raw water line off to the disassembled manifold and put it on the muffs to protect the water pump impeller.
Thoughts?

 

[81 Checkmate]

Re: 4.3l mercruiser with steam from vent lines

Ok want to get the milky oil out as much as posible.

Unhook your center coil wire so it wont start......
Unhook the inlet hose from drive on motor and route it to the ground...to keep water from spraying all over...
Attach water hose to drive...........
Add alittle diesel to oil......
Pull spark plugs...ease the motor turning over.

Turn over motor with starter for a short period...dont wanta burn that up..

Drain oil from pan.....Go get the cheapest oil and filter you can find and replace oil/filter......
Then once you get it running again to temp......put your good oil/filter in it.

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Thanks again Checkmate!

I'll probably put a little lube down the cylinders too. I think I'm on the home stretch

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

Hopefully this is the last question. I could not get the oil filter off tonight. I had added 1 quart of diesel to the oil as noted above and have drained the oil. This engine was run in fresh water. Should I add oil now? I am concerned about it rusting between now and Sunday when I plan to finish the job.

 

[rock doc]

Re: 4.3l mercruiser with steam from vent lines

I decided to fill her with fresh oil and cycle it a few times with a starter. The best I could do. Thankfully there wasn't that much water in the oil to begin with.