Mercruiser 181 3.0 problem

[jwsimmons]

I just bought a boat with a 3.0 liter 181 mercruiser engine by GM. The day after I brought it over into my cold climate I was told you need to pull the freeze plugs on I/O's during cold weather. Me being new to I/O's didn't know anything about it but found the freeze plug and pulled it. No water came out so I put a heater in the console and then melted the water out of the lines.
What all types of damage am I looking at? What are the odds of them happening and what type of symptoms should I look for?
Thank you and any input is appreciated greatly

 

[ziggy]

Re: Mercruiser 181 3.0 problem

hum, that don't sound good jw....someone else will let ya know where it most likely broke at. ya gotta, at the very least, drain all water from an i/o prior to freezein temps. meltin the water out of the lines with a heater don't sound real inspirein. anything that's got water in it has to be drained. manifolds, block, coolin lines if applicitable, maybe more. otherwise yer most likely hosed somewhere, block, manifolds?...........if ya get a hip oem service manual for yer perticular engine, drive package, ya will find all the info nessesary for takein care of yer new boat, includin how to drain the water out of it......bet if ya list yer serial #'s for yer engine and drive someone will let ya know exactly what book to get too.......havein the facts about what ya got is great....also, leave the freeze plugs in, unless the feeze pop'ed them out. ya want to drain the water out with the drain plugs, usually located on the block, manifold, and riser....

 

[whywhyzed]

Re: Mercruiser 181 3.0 problem

You can't pull a freeze plug out- you have to smash it in and then turn it sideways - what are you calling a freeze plug? The drains?

What usually happens on 3.0's is the block cracks in a few common places:
1. Between the frost plugs on the port side of the block
2. parallel to the head/block mating surface about 1/2" below the head
3. Lower front area of block port side.

For 1 and 2 - hang upside down under the intake/exh manifold with a bright flashlight- you'll see if it cracked.

If the engine oil is real high on the dipstick - that's because it cracked internally and the oil is floating on a gallon or so of water.

The exhaust manifolds like to crack underneath straight forward from the drain fitting(s).

 

[jwsimmons]

Re: Mercruiser 181 3.0 problem

Yes, I suppose I have called the drains "freeze plugs." I am just talking about the wing nut like plugs that you unscrew on the engine and water comes out. I have a seloc manual for '64-'91 mercruiser. The manual calls the drains cylinder block petcock, exhaust manifold drain plug and exaust elbow drain plug. I will try your advice tomarrow kjdkjd and keep you posted.

 

[jwsimmons]

Re: Mercruiser 181 3.0 problem

Ok, I looked all around for cracks but couldn't see any. I checked the oil but it looked normal. I fired up the engine for about 5 minutes and didn't see any leaking, I also changed the oil and then fired up the engine for a few more minutes, I then shut the engine off and checked the oil again, again it didn't look suspicous. I ran the engine and then checked the oil a few more times but never saw the level raise or any bubles/ water looking substance.
Do you think I ran the engine enough to know if the internal is cracked or to see water runing down the outside of the block? If there was oil on the dipstick should the water sit above or below the oil?

 

[Reel Poor]

Re: Mercruiser 181 3.0 problem

What year Mercruiser, and do you have the serial # for your engine?

The oil will sit on top of the water. If the engine is run with water in the oil the oil will turn a milky color. Sounds like you got lucky.

 

[wncrjb]

Re: Mercruiser 181 3.0 problem

If you fired up the motor and ran it for 5 minutes like you stated.... did you do this with muffs on the drive? if not,plan on a new impeller before putting it back in the water.
When you open up the drains and nothing comes out, take a small stiff wire ( like a coat hanger ) and run it in the drain hole to dis-lodge any small particles that may be blocking the opening.. Also disconnect the lower hose on the water pump to make sure there is no water in there.
Also, keep your drive in the lower position to keep any water from building up behind the prop, this also keeps your bellows from stretching and cracking over the winter.

 

[jwsimmons]

Re: Mercruiser 181 3.0 problem

no, I ran the engine with muffs on it. I'm not much of a mechanic but I do know how important it is to take care of a lower unit. I do need to drain my gas tank and would like to know how to do that without running the engine all day. I don't think I can use fuel stabilizer because I only know there is roughly half a tank and I don't know the tank size.
I will get that serial number as soon as I can.

 

[wncrjb]

Re: Mercruiser 181 3.0 problem

I'm glad to hear you ran it with the muffs on. Saves alot of extra work like I did.. When I went to look at my boat, I ran it to make sure the motor ran fine and forgot all about the muffs....learned real quick on replacing a impeller LOL... I'm sure others on here have better ways of draining fuel but all I did was un-hook the fuel line at the fuel pump and hook up a 12 volt electric fuel pump I had left over from my racing days and pumped her dry. I then started the motor and it only ran a minute or so till the carb went dry. I'm still not sure which is better, draining all the fuel or filling it to the top with added stabalizer. I drained mine because I had to rebuild the carb and wanted to pull the fuel tank anyhow.

 

[ziggy]

Re: Mercruiser 181 3.0 problem

does sound like ya may have got lucky. cool. i had water intrusion in my engine last fall. (a bum manifold) the oil looks like chocolate milk when mixed with water. keep checkin it for a bit to make sure ya aint got issues. as for removein the fuel. i have used a hand siphone pump and had good success with that. or ya could go look on yer fuel tank. probably by the sender on the fuel tank itself. should be a tag that states capacity. then ya could just do the stabil thing. if ya do, ya should run it for a bit with the stabill to get it throughout the fuel lines and into the carb. i guess if it's a metal fuel tank i'd think a full fuel tank would be best, to inhibit corrosion on the inside. if a plastic tank, i don't know that it matters, full or empty. just not half way full.......yer just tyin to not let the condeinsation (water) inside the tank mix with yer fuel or promote corrosion if empty....

 

[cobra 3.0]

Re: Mercruiser 181 3.0 problem

Poke in the holes with a wire because there is often flaked metal and sometimes old impeller pieces blocking the holes for a proper drain.

Also, if you have power steering, drain the cooler by pulling the hoses apart.

 

[jwsimmons]

Re: Mercruiser 181 3.0 problem

The serial # to my engine is A490712 for those who asked. I don't have power steering. Besides power steering, the exaust manifold and the engine block are the only other to worry about draining right? My boat, engine, outdrive are all 1985, so I don't have all the modernized equipment.

 

[Reel Poor]

Re: Mercruiser 181 3.0 problem

That serial # doesn't sound right. Should be between 6229718 THRU 0C856558. Not that it's really revelent now. I was thinking there might be an online manual avaliable for your engine but it's for later models, like 90 up.