Replacing Engine Freshwater/Antifreeze

[Cheechako]

hmmm... that reminds me... someday I've got to change the coolant in my car... let's see... been 7 years now... oh well, maybe next year...

[chala]

Originally Posted by colemj

If the different coolants comply to the same standards,

Yes if.

When you see a seized engine with a circulating pump impeller eaten away then it is possible to understand that the mixing of different coolant was not successful. An easy but expansive way of learning not to mix coolants.

[colemj]

Originally Posted by Mundinho

There is no real need to replace the coolant. However you must ensure your coolant mix stay the correct mix, being 50% (distilled) water-glycol or higher % glycol. If you fill up your coolant over 2 years even very occasionally, you dilute the mix. Ii must be at least 50%. In commercial applications we use even higher then 50%. However higher glycol is higher cost. Also higher glycol % is reducing the heat carrying capability, so if you run your engine often at max power you must not go higher then50% glycol. There is no need to buy brand specific coolants. Good quality glycol is what you need and most good quality coolants are made up off.

There are many poor quality glycol for sale, so be aware, you pay what you get.

There certainly is a need to replace coolant - every single manufacturer that I know of demands it.

If necessary to top off, I fill up with coolant mix, not water, so no dilution.

50% can actually be too high in some environments/applications. Our generator specifically specifies 30%.

Glycol is the antifreeze/antiboil component. Corrosion and other inhibitors are important also (probably more important).

Absolutely you get what you pay for - go for top brands.

Mark

[colemj]

Originally Posted by chala

Yes if.

When you see a seized engine with a circulating pump impeller eaten away then it is possible to understand that the mixing of different coolant was not successful. An easy but expansive way of learning not to mix coolants.

Well, by "if", I assumed the person would read the labels, not just take a random guess...

What if you mixed in a higher quality coolant than what your engine manufacturer sold you?

I don't understand your circulating pump example. The Volvo D-series are known pump impeller problems, even when using Volvo fluids. An example like yours could be due to anything - including someone not reading labels.

Not sure why you have picked this argument. I just presented some facts regarding the historical and present meaning of colorants, a somewhat recent change toward universal formulations, the existence of performance standards and that no engine manufacturer makes its own "special formula" coolants.

All of that can be found on-line. I'm not arguing your personal practice in any way.

Mark

[HappyMdRSailor]

Originally Posted by Guy

Big trucks just filter it and keep going and some auto lube joints will clean it also.

I can just see some guy plumbing this through his Racor's now....

[Cheechako]

Originally Posted by chala

Yes if.

When you see a seized engine with a circulating pump impeller eaten away then it is possible to understand that the mixing of different coolant was not successful. An easy but expansive way of learning not to mix coolants.

How would you know? maybe possible it's cavitation?

[Dennis.G]

The link below is a paper that describes some of the different considerations in diesel engine coolants. Really need to look for engine manufacturer's recommendations.
http://www.genosgarage.com/GenosGara...Antifreeze.pdf

[bstreep]

Originally Posted by Mundinho

There is no real need to replace the coolant. However you must ensure your coolant mix stay the correct mix, being 50% (distilled) water-glycol or higher % glycol. If you fill up your coolant over 2 years even very occasionally, you dilute the mix. Ii must be at least 50%. In commercial applications we use even higher then 50%. However higher glycol is higher cost. Also higher glycol % is reducing the heat carrying capability, so if you run your engine often at max power you must not go higher then50% glycol. There is no need to buy brand specific coolants. Good quality glycol is what you need and most good quality coolants are made up off.

There are many poor quality glycol for sale, so be aware, you pay what you get.

Folks please note the above. Using more than 50% coolant to water WIlL impact substantially your cooling ability. Water has twice the heat transfer rate as glycol. Using 30% glycol will substantially improve heat transfer. Using all or nearly all coolant will crush your heat transfer.

[Uncle Arthur]

I have a yanmar 3ym20 bought new in 2005 never missed a beat . Changed the coolant for the first time two days ago , easy to get out and looked as good as the Yanmar coolant that i am putting back in which cost me $40 Nz !
Putting the coolant back in was/is a problem as i did it while out of the water and could only get 1 litre in when it needs about 4 . I waited til back in the water as i heard over the internet that the motor has to run to heat up and open the thermostat .

[Uncle Arthur]

Sorry to carry on as this zoomed off too early !!!

Well after running the motor for 10 minutes i managed to add another 2 litres. I still feel that it needs another litre plus
judging from what i got out .I added the coolant through through the heat exchanger on top of the motor , also filled the overflow tank to the max level
Any ideas as to how i figure out if i have an air block , after running the motor for i went back to my berth taking 10 mins at 3000 rpm still no change in coolant level.
I plan to keep an eye on it.

[sailorboy1]

so according the poll votes 80% don't replace the coolant each year like the manual says

wonder how the that compares to those who replace the seawater impeller

[chala]

Originally Posted by Uncle Arthur

could only get 1 litre in when it needs about 4

How much did you remove, 4 litres? I do not know about Yanmar but with Perkins and most engines, it is not necessary to run the engine with little coolant to fill up the coolant. There is a bleed channel that bypasses the thermostat. 4 litres plus come out, 4 litres plus goes in and only a little top up is required. Check with Yanmar. To run an engine with not enough coolant is a bad idea.

Originally Posted by Uncle Arthur

I added the coolant through through the heat exchanger on top of the motor , also filled the overflow tank to the max level

Make sure the coolant fill completely the heat exchanger to the top. With an expansion tank (overflow tank) it should be no air between the coolant and the cap. You may have to top up until everything settle down.The coolant level should only reach Max when the coolant is hot. Cold I like the level to be at Min.

Originally Posted by Uncle Arthur

and looked as good as the Yanmar coolant that i am putting back in which cost me $40 Nz !

I know the feeling when I go to the urinal after some good beer.

[chala]

The poll did not mention.

Originally Posted by Don L

like the manual says

The poll should have been more or less like “do you maintain your engine as per manufacturer recommendations in regard to replacing engine coolant”.

[Hudson Force]

Brief Digression: I was recently looking at the gallon jugs of coolant in an auto supply store. There was one price for the coolant and then a higher price for the same coolant that was "pre-mixed" to 50% distilled water. Huge rip-off! "Let's dilute it by half with water and charge more for it! ...They'll buy it!"

[Cheechako]

On my perkins 4-108 I had to remove the thermostat and fill the block with coolant. When I ran the engine prior to that the t-stat was closed and created an air lock... so it wouldnt open even when the engine heated up because it was surrounded by air.