water in oil Mercruiser 4.3...Please Help!

[leo319]

Thanks so much in advance for all the help. Greatly appreciated.

 

[kewlkatdady]

Re: water in oil Mercruiser 4.3...Please Help!

sounds very familiar to how my problems started...

I'll be replacing the motor once my new long block gets here early next week.

What is the fluid level on the dipstick?

If its real high...more chances than not you have a cracked block.

the 4.3's are kinda know to crack under the intake manifold. I have not disassembled mine old one yet, but I'm 99% sure I know what I'm going to find.

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

yeah ive heard about 4.3 cracking down under the manifold... Why are you replacing your block? Same problem i have took you there?

Yeah today when i changed the oil the level was very high up the dipstick.. so thats a good sign then? What else should i be looking for?

 

[Alpheus]

Re: water in oil Mercruiser 4.3...Please Help!

You'd be surprised how good an engine can run with a cracked block.


How old are the risers and exhaust manifolds?

Is the boat used in salt water?


The only way you can confirm a cracked block is to pressure test your engines cooling passages. There is no kits or standards on how to do this.

Basically you have to pressurize your block with 15 psi of air. You do this by taking hoses off and plugging them with hose clamp and whatever you can find that will plug the hole. Pieces of broom stick,dowel rod,capped off PVC pipe or pinch shut the hose.Rig up a pressure gauge and induce air into the engine and listen for a leak...

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

i cant tell if the risers and exhaust manifolds have been changed or not, so ill assume theyre been there the age of the engine...its a 97.

i bought the boat from the original owner and he said boat never been in salt water, but you a know you cant trust sellers word most of the times... ive never used the boat in salt water since i owned it. Haven't seen any signs of rust on the boat nor on the trailer..

ill look into pressure testing the cooling system. i will read more on it tho just so i do it right and no mistakes during testing.

Any other way to find out whats could be wrong.?
want to know what else i need to check on and get the steps to have problem fixed...((asking for alot huh??.)) Thanks so far for the replies guys...

 

[Bondo]

Re: water in oil Mercruiser 4.3...Please Help!

and get the steps to have problem fixed.

Ayuh,... Remove the motor, 'n Change the Block....

 

[ziggy]

Re: water in oil Mercruiser 4.3...Please Help!

ya should read this.. it's from the adults only sticky...

http://forums.iboats.com/showthread.php?t=369864

this wasn't around when i had water in my oil, but the second link in that thread was. read that for sure. i did what was in that thread and saved my engine. my issue was spent manifold and riser.

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

very helpful link. thanks.. i really hope i dont have to do what Bond-0 said...

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

What good is it if I change the oil again (know that I just changed the oil/filter yesterday)so kinda flush the engine with new oil to see how much water is coming in? Would that be a good way to see how major my problem is? Will water get in just with the muffs on?

Is it easier to induce air into the cooling system to check for leaks it if cracked? What about if the a gasket or heads are blown, how can I find that out?

 

[dubs283]

Re: water in oil Mercruiser 4.3...Please Help!

yep, start with the level on the dipstick that you can mark or remember where it is

run the engine on the muffs til its good and warm - 20 mins to 1/2 hr

shut down and let the engine sit for 20 mins to 1/2 hr to get a good heat soak

restart the engine and let it run for another 20 min to 1/2 hr - then check the level on the dipstick

you will see if the oil is getting milky and if it is rising

on 4.3's - some had a square plug in the front of the intake manifold below the t-stat housing - this needs to be removed for proper winterization (drains water out)

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

yeah i will do that. now i have a question about winterization but ill probably start another thread. just wondering if i need to winterize if i wanna work on the boat inside the garage this winter (i mean it sounds like i have lots of worj to do). the area where i live never goes below 40F during winter and inside the garage should be warmer...

 

[dubs283]

Re: water in oil Mercruiser 4.3...Please Help!

once the engine is winterized, its winterized

if you run it with water on the muffs or in the boat on the water you MUST winterize it again to protect from freeze damage

to be safe, after running it, drain the block and manifolds to protect from freeze damage

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

ok. yeah im thinking about just drain after every time i run the engine...but i dont think that will happen until later on.. i mean today we hit 70F and at night dont go below 50F just yet...

 

[leo319]

Re: water in oil Mercruiser 4.3...Please Help!

so what should i check first to find out what my problem is? check for a cracked block? blown headgasket? what do you guys think?/

 

[Bondo]

Re: water in oil Mercruiser 4.3...Please Help!

so what should i check first to find out what my problem is? check for a cracked block? blown headgasket? what do you guys think?/

Ayuh,... Sounds like the PO also thought it Never Freezes where he lives too...

Drain, 'n Pressure test the cooling system with air,... about 15psi is plenty...

 

[Alpheus]

Re: water in oil Mercruiser 4.3...Please Help!

What about if the a gasket or heads are blown, how can I find that out?

You can find a bad head gasket by doing a leak down test...

http://www.youtube.com/watch?v=ofSiTGeLXvc&feature=related