Oil In Coolant, Critical Condition?

[Neo]

She starts like a dream now, first time, every time.

I guage vibration at 2800 relative to the sweet spot at 2600. Not sure what is normal.

I also have a tapping that sound like the valves. Not sure what is normal in that regard either.

Maybe I'll post a video.

[hellosailor]

I cringe when I hear "freshwater" for a cooling system. To some people it means the fresh, not salt, water the boat is sailing in. To others it means the fresh water they've used instead of an antifreeze mix in the closed side of the cooling system.

If rust in the freshwater side means rust in the closed loop of the cooling system, that still really shouldn't be fresh water. It should be rusting if it was just filled with water! It is supposed to be filled with a coolant mixture, and all but the cheapest antifreeze will also contain anti-rust compounds and water pump lubricants. You can also buy a can of those additives, and add them to the system every year as they are consumed in normal use.

The closed loop will also last longer if you use distilled or deionized water, not tap water, because you never know if the tap water contains minerals that will react to the solder and other metals in the cooling passages. And there's some question of how chlorinated urban waters react to gasket materials now.

So, just one man's opinion. I prefer not to hear "freshwater" unless someone means the stuff we're drinking.

Neo-
Did anyone tell you that the head bolts have to be retorqued, sometime after the head was replaced? 10 hours, 50 hours, something like that? If the head isn't retorqued, the new head gasket will be leaking.
If your rings were at all questionable, the shop that worked on the engine should have pointed that out to you while it was apart. It shouldn't need to be taken apart AGAIN to do the rings, that would be a lot of wasted duplicate time and money.

[sailorchic34]

Hum, Yanmar among others calls the closed loop system a "fresh water" system. Pretty common with the marine engine manufactures.

I've looked in the yanmar service manual and operation manual and yanmar does not list a requirement to retorque the head. This is sometimes required and use to be required back before 1960's I think after a head gasket replacement. Show of hands, how many folks here have retorqued their new car heads (not counting LBC's - little British cars and the like) in the last 40 years.

Its not all that bad an idea. But care must be taken, not to loosen the head bolt too much before retorgueing to 75 foot pounds. I'm still debating with myself about touching the head bolts. BTW, I torqued my to 79 foot pounds in 10 pound segments, so its pretty good. At the moment I'm thinking of not retorqueing.

If oil is used on the head b

[hellosailor]

sailorchic, I don't disagree with you, retorquing is best done only when the maker says to do it, as there are different types of head bolts. It ids judt one of the simple things often not donet hat can lead to a new head gasket failing.

As to whether Yanmar says "fresh water"...ignoring the fact that they may be perpetuating a bad translation that was done years ago, I've learned that if you don't use terms and phrases which are ambiguous or confusing, you wind up communicating better, and fewer mistakes are made. And to avoid jargon, which is partly designed to conceal meanings from "outsiders".

Last time I had some steel work done, I thought it was all arranged. Then I realized, from the guy I spoke to, to the actual guy who would be doing the work, there was no absolutely positive way to tell which side of a plate was to be beveled. Quick sketch, fax machine, all confusion gone and the jobwas done right the first time.

Frssh water side...right, every boat sold in the Great Lakes is after all advertised as a fresh water boat. Obviously, that boat has a fresh water side--versus the closed loop fullof not fresh not water. What could possibly get confused there?

[sailorchic34]

Actually its not just Yanmar, but Beta, Volvo Penta, etc., all call it freshwater cooling, fresh and raw water pumps etc., on their current literature. Very common terminology on marine engines.

Gee I would call it standard terminology, as pretty much everyone is using it, that is "fresh water cooling", to refer to a marine engine with a heat exchanger/ tank, pump. Maybe all the manufactures are wrong too.

Even on freshwater lakes, the lake water would be raw water and the fresh water side would be the tank, freshwater pump, etc. Gee pretty much all manufacturers call if a fresh water cooling system.

Yes it could be confusing. But then so is their, there, your and you're. Got to love English.

BTW it's called fresh water cooling as in its original form, they put straight fresh water in the tank with a little corrosion inhibitor. Matter of fact, my Yanmar 3GM30f owners manual, indicates to use fresh water with a corrosion inhibitor.

[pbiJim]

These days there are several types of anti-freeze & most all of them contain anti-corrosion chemicals. Most all of them tell you to replace or refresh the coolant after a specified number of years. The different colors of coolants are each formulated to give better protection to different combinations of types of metals, which is why certain coolants are recommended for certain engines. Most any modern anti-freeze will work at least fairly well in most engines as long as you use a 50/50 mix with water & as long as you DO NOT MIX more than one type of anti-freeze. Some mixes are worse than others. The worst ones will form a gel & stop all cooling quite quickly. Straight anti-freeze is a bad thing. Straight water is OK for a short time in an emergency, but not for long term use.

Heads normally need to be retorqued after the engine has been hot & cold a few times. You often need to readjust your valves after retorquing the head on a valve-in-head motor.

Tapping noise from the valves often means that the valve lash is loose if you have solid lifters. It can also indicate a problem with hydraulic lifters if the engine is so equipped. Loose valve clearances are noisy & beat up the valve train a little over time. Tight valve clearances burn valve seats pretty darn fast & ruin compression.

These are just general comments about typical motors. They are not specific to that particular motor.

[pbiJim]

Also,
excessive vibration at normal RPM usually indicates that something inside the engine is either loose or out of balance.

I've seen a brand new engine use a lot of oil because the oil rings on one piston had been installed upside down. Compression was normal.

[Neo]

Originally Posted by hellosailor

I cringe when I hear "freshwater" for a cooling system. To some people it means the fresh, not salt, water the boat is sailing in. To others it means the fresh water they've used instead of an antifreeze mix in the closed side of the cooling system.

If rust in the freshwater side means rust in the closed loop of the cooling system, that still really shouldn't be fresh water. It should be rusting if it was just filled with water! It is supposed to be filled with a coolant mixture, and all but the cheapest antifreeze will also contain anti-rust compounds and water pump lubricants. You can also buy a can of those additives, and add them to the system every year as they are consumed in normal use.

The closed loop will also last longer if you use distilled or deionized water, not tap water, because you never know if the tap water contains minerals that will react to the solder and other metals in the cooling passages. And there's some question of how chlorinated urban waters react to gasket materials now.

So, just one man's opinion. I prefer not to hear "freshwater" unless someone means the stuff we're drinking.

Neo-
Did anyone tell you that the head bolts have to be retorqued, sometime after the head was replaced? 10 hours, 50 hours, something like that? If the head isn't retorqued, the new head gasket will be leaking.
If your rings were at all questionable, the shop that worked on the engine should have pointed that out to you while it was apart. It shouldn't need to be taken apart AGAIN to do the rings, that would be a lot of wasted duplicate time and money.

I couldn't think of a better term, and as Sailor chic mentions, that is what yanmar calls it. But I do like the term closed loop better than fresh water. I'll use that one next time, if I can remember.

I didn't decide to do the job until the end of April, and I only had a few weeks to do the job. GOTTA SAIL!. So, I replaced the head gasket without pulling the engine. Only the head went to the machine shop for a pressure test and re-surface.

[Neo]

Originally Posted by pbiJim

Heads normally need to be retorqued after the engine has been hot & cold a few times. You often need to readjust your valves after retorquing the head on a valve-in-head motor.

Tapping noise from the valves often means that the valve lash is loose if you have solid lifters. It can also indicate a problem with hydraulic lifters if the engine is so equipped. Loose valve clearances are noisy & beat up the valve train a little over time. Tight valve clearances burn valve seats pretty darn fast & ruin compression.

These are just general comments about typical motors. They are not specific to that particular motor.

Thanks. This is my first head job. I'll have to look up the definition of lash. And I'll think about checking the valve clearance as well.

[Neo]

Originally Posted by sailorchic34

Its not all that bad an idea. But care must be taken, not to loosen the head bolt too much before retorgueing to 75 foot pounds. I'm still debating with myself about touching the head bolts. BTW, I torqued my to 79 foot pounds in 10 pound segments, so its pretty good. At the moment I'm thinking of not retorqueing.

I've been have the same debate with myself about the re-torque. Leave well enough alone? One poster said that the newer head gaskets (metal covered with plastic/rubber?) do not require re-torquing. And I'm just not sure how many 1/2 turns to loosen the bolts before re-torquing.

I'll read through your "I was bored..' thread when I get a chance to see if I can learn anything.

[sailorchic34]

I believe that a 1/8 to 1/4 turn will be more then enough enough to loosen. That's about 10-15 foot pounds based on when I torqued my head. Its not advised to loosen too far as there will be uneven load on the head.

[pbiJim]

Originally Posted by Neo

Thanks. This is my first head job. I'll have to look up the definition of lash. And I'll think about checking the valve clearance as well.

Sorry about that. Lash is basically the same as clearance. Valve lash is the space between the components of the valve/lifter/cam system. You need a little lash to allow for parts expanding when they get hot, but you don't want a whole lot more than necessary. The repair book for the particular motor you are working on should give you the specified range of clearance that is recommended. Don't be surprised if the exhaust valve spec is a little larger than the intake valve spec. That is often the case as the exhaust valves tend to run hotter.

[pbiJim]

Originally Posted by Neo

I'm just not sure how many 1/2 turns to loosen the bolts before re-torquing.

I normally don't back off the bolts before retorquing. I just put the torque wrench back on the bolt heads & go to the same number again. If the bolts move, then they needed it. If they don't move, then all was fine already.

Basically, you are just making up for compression of the new gasket.

If the bolts did not move, then you probably don't need to touch the valve adjustments until the next specified maintenance interval.