Mercruiser 3.0 Engine disassembly - Day 15

We've got water damage in our engine! Tons of water inside the crankcase! Rust inside the intake/exhaust manifold.
Boat: 1998 Bayliner Capri 1850 LS
Engine: 1998 Mercruiser 3.0L 4-cylinder 135HP ( GM 181 marine block)
Music Credit:
Song: SKANDR - Summer Booty (Vlog No Copyright Music)
Music provided by Vlog No Copyright Music.
Video Link: • SKANDR - Summer Booty ...

[@wyattholliday1]

I’ve been binging on your videos since I found them this morning. I admire you for taking on such a big project with the boat and engine and presenting it in a good honest way that shows your learning process as you go. Thank you for not editing those learning moments out because it helps me and others to learn right along with you. Those embarrassing and frustrating things is called learning and getting better and when it’s all said and done things to look back and laugh on. Keep up the great work!

[@ZachsGarage1]

Thanks! Very well said, I really appreciate your admiration

[@marcmacdonald5862]

I love that even though at this time, you didnt know the difference between a piston rod and a dipstick, this lack of experience didn't stop you from completely tearing the engine apart and eventually rebuilding it. You could have easily edited this out as well, but you included it. Great job!

[@ZachsGarage1]

I laughed at myself later on for that 😝 I think it's good for people to see I didn't start out as an engine mechanic. This was my first rebuild top to bottom. I learned so much about engines, it's crazy

[@mickeymaroney9114]

@@ZachsGarage1 that's how we learn for sure...not one master mechanic knew what he was doing the first time round

[@marcmacdonald5862]

I know guys who been working on cars theyre whole life and wont tackle an engine rebuild

[@robertvillafane3753]

There’s two things you never want to reuse Condoms and Head Gaskets

[@benjaminmeadows1380]

I did reuse a head gasket once a,and work on 350 buddy's truck still ran

[@thediplomasta5891]

On a 3.0 specifically, if it's not perfectly tuned, sometimes it will diesel when you shut it off. When it does that, the motor spins backwards for a second, before it comes to a stop. That backwards movement sucks water back into the motor from the exhaust. usually cylinder #4 gets the brunt of it. If you pull the spark plugs out and turn the motor over with the starter, you'll see some water squirt out of the #4 hole (or more). Over time this will get water in the oil which will scratch the babbitt bearings and cause a slowly increasing permanent loss of oil pressure until either the motor locks up (like yours), or it won't make any power under load. The latter, is MY current situation. The other way that water gets in the oil is more common: the riser gasket leaks. This is usually caused by some jackwagon trying to reseal an old gasket with RTV. This is the 2nd most important gasket on the whole engine! Don't do that! Make sure it's perfectly flat, clean, and dry anytime you install a NEW riser gasket; which you must do any time you remove the riser for any reason. Don't be cheap. It costs much more, later.

[@ZachsGarage1]

That was also the conclusion I came to! ....after working on it for over a year lol

[@thediplomasta5891]

@@ZachsGarage1 it takes a lot of time, these things.

[@easyamp123]

That water is not rusty, some ray of hope

[@mrsuarez430]

if you change the oil frequently either you can run a line from the bottom of the pan or you can suck out the oil with a hose and pump out of the dip stick if possible warm up the oil a little.. MY boats a searay so barely any space for even an oil change

[@CCROSS5882]

there is a filter behind the big nut on the carb where you removed the fuel pipe.

[@andrewarmstrong7310]

The Mercruiser 3.0 was notorious for blowing head gaskets and the block rotting from the inside out, make sure you use a competent machine shop to have it checked out.

[@ZachsGarage1]

Good machine shops that have the equipment to bore cylinders are hard to come by nowadays. I'm happy to say I found one that did a great job

[@hustlerman1231]

Hey im currently rebuilding my 1998 3.0 merc do you have a video on removing and installing the timing gears I really need some help

[@jopra49]

A job ahead of me for the same reason, Engine Seized!

[@lodwill5116]

No you can’t reuse head gasket. Most are compression gaskets.

[@trentidfwy3770]

so i had about a quart of water come out of teh oil pan of a 1988 thompson i just got.... so should i be planning on ripping out the motor now also?

[@ZachsGarage1]

Possibly. Was there rust in the water?

[@Joshfasig]

Hey I would like to get in touch with you on some tips on how to restore a boat I just bought a 1984 advantage mercruiser 3.0 and idk nothing about fixing this up

[@ZachsGarage1]

Thanks for your comment! I honestly didn't know anything to start either. KZbin video can really help you learn if you're a visual learner. I have a playlist of all the videos on my Bayliner boat restoration. Feel free to email me at [e-mail]

[@joeydrumstix]

Hey Zach can you please tell me a good online source for these mercruiser engine parts?

[@mikelaba8985]

You put oil in the cylinder head was this to check for a piston ring leak?

[@ZachsGarage1]

It was to lube it up, to try and get it unseized, but the oil didn't leak down that 4th cylinder, because it was rusted shut

[@scottthurman-me8yg]

It’s an older engine..it’s not going to be sterile

[@andygarcia5769]

How much is to rebuild a exact same engine with the same issues?

[@ZachsGarage1]

$1,300 I break down all of my costs here: docs.google.com/spreadsheets/u/0/d/151qjGcmrvE5JpPQ8q5yXeylS3ly_TJpWVcAeYYnLgY0/htmlview

[@barry.anderberg]

Are you self taught? I would love to try doing something like this.

[@dirtzilla500]

so after final inspection did the water go into motor from bad intake gasket ?

[@ZachsGarage1]

I believe it was actually the exhaust riser gasket

[@dirtzilla500]

tks for the reply, the riser would be the end part shown in ur video ?

[@ZachsGarage1]

@@dirtzilla500The riser itself is already off the engine in this video. But where the gasket goes is in-between the exhaust manifold and the exhaust riser. You can see where at 8:32, to the right of the carburetor

[@dirtzilla500]

tks,

[@fastfeh1]

NO! you can NOT reuse the head gasket.

[@ZachsGarage1]

I ended up getting a new head gasket since it came in a kit, so I do not have to worry. For anyone who doesn't know, replacing the gasket by rule of thumb is the safe thing to do, when assembled the engine crushes the gasket conforming it to the shape of the seal, so re-using it risks having leaks in that seal

[@randyrivera611]

How much did you spent to fixed the engine?

[@ZachsGarage1]

@@randyrivera611 to get the cylinders overbored +.03" by a machine shop was about $200. Then another $150 for new pistons and piston rings

[@jdcook65]

Why would you even hint at reusing a head gasket??? JS

[@robrector9456]

Something's not right here when water and oil mix it turns milky He drained water out and then black oil came out

[@ZachsGarage1]

Water and oil mix... Eventually. I think the water at the bottom was perhaps from me dipping the boat in the lake without the plug by accident only a week or two earlier. I didn't realize it at the time, but in hindsight I think that's why

[@sinanguner1384]

I hv 4 cylindir Omc marine engine No water inside oil no water leak oil wery clean bat engine turn wery ruff 2 new Marine Battery fully charge i take out lower unit replace lower unit oil new gear oil olso i replace shifter cable new gascet install lower unit back on the rear turn key motor not start turn wery wery ruf i need your apenien

[@ZachsGarage1]

Thanks for the comment! If I understand correctly, there seems to be extra resistance keeping it from turning as well as it should, correct? If so, I would try to identify what is causing it to turn rough. There are a lot of things that could cause it, first and easiest thing I would try is removing the outdrive and then try to start it to see if it turns better

[@abdullahgazhy9828]

،،

[@chriscobb4939]

Water runs thru the head u don't know wat u are doing