Engine coolant checks - do you do them?

Engine coolant testing - do you do them?

When we first got our vessel 4 years ago, even though the coolant looked fine we dropped it, flushed and replaced and figured see you in 5 years.

As I want to replace some of the hoses now I thought I would drop flush and replace again at the same time.

It was brought to my attention that diesel engines can need a bit "more" especially those with wet liners which the 855 Cummins has.

We have water filters which, after a bit more research I found have an additive to refresh the coolant.
I have spares so will replace
I have also bought testing strips to check coolant effectiveness.

And here was me thinking clean fuel and oil and if the coolant was full and green we were good to go.
I change anodes and rod out the HE on a yearly basis, temps never go above 82c so figured all good.

https://www.knowyourparts.com/technical-resources/diesel-engines/diesel-engine-coolant-maintenance/

Just starting to learn more about this.
Have a sample pulled from motorhome ready to send in and another bottle for boat sample come spring.
I had a tough time sorting things out on MH as Cummins said one thing Freightliner another about what types of coolant can / should be used.

If you change your coolant filter after testing, it should bring back the correct level of additives and so yes, you need to check. If you are keel-cooled, the quantities are much larger and you might need to add some yourself.
I have Cat strips for my Cummins, I haven't researched another source.

If you let the coolant expire, you run a huge risk of engine damage due to cavitation.

A good quality 5 year coolant with the Cummins approvals will do it.

Castrol strips x 50 is what I just purchased
https://www.ebay.com.au/itm/111943-...rentrq:06ba08251760aa6a45b8dc4bffe438fa|iid:1

A few other breeds and sources here

https://www.ebay.com.au/sch/i.html?...Desc=0&_osacat=0&_odkw=penrite+testing+strips

Xsbank said:

A good quality 5 year coolant with the Cummins approvals will do it.

Click to expand...

The one I use says.....

Trade Direct Long Life OAT Coolant Concentrate is a premium quality coolant that has been independently verified to all relevant ASTM’s for automotive and heavy duty diesel use. This coolant provides maximum protection against ‘hot spot’ corrosion, common in aluminium cylinder heads. Trade Direct Long Life AC-9 coolant uses Carboxylate technology to provide a long drain service life of up to 10 years / 1,000,000kms* in automotive applications and up to 6 years 600,000kms / 6,000hrs* in heavy duty diesels. This has obvious environmental advantages as a result of fewer coolant changes. There are no harmful effects on hoses or gaskets. (* at 50/50 dilution ratio) Has a proven record over many years with marine engines, mining equipment, taxi fleets, government departments, bus companies and several large fleet truck companies.

https://www.supercheapauto.com.au/p.../550937.html#q=oat+coolant&lang=en_AU&start=1

Click to expand...

Hasn't got Cummins tick but has got Ford, GM, BMW, Volvo

A couple of articles on why coolant chemistry is important
Diesel Engine Coolant Maintenance
Coolant pH

And links to test kits
Fleetguard Coolant Analysis Test Kit CC2602A
Baldwin Filters Coolant Test Strips
Cummins Coolant Test Strips

Portage_Bay said:

And links to test kits
Fleetguard Coolant Analysis Test Kit CC2602A
Baldwin Filters Coolant Test Strips
Cummins Coolant Test Strips

Click to expand...

Geez they dont miss you there
Single strip for $10.60 / each
Vs
$25 for the castrol ones I linked to above and you get 50

Yanmar has specific requirements for the type coolant, and it is to be changed in my engine at 250-hour intervals or biannually. So I don't feel any need to test it - just change it and move on.

Simi 60 said:

The one I use says.....
Hasn't got Cummins tick but has got Ford, GM, BMW, Volvo

Click to expand...

Simi,
Sounds like your coolant is OAT type. (Organic Acid Technology). No need to test or add extra additives to this. Unlike standard coolants these don't use nitrites in their mix. It will last the 5 years the way it is.

Just make sure you don't mix your OAT type coolant with the standard green coolant with nitrites. It will gel and need a good flush and change.

Their is a 3rd type of coolant called HOAT (Hybrid Organic Acid Technology). It is similar to OAT with the 5 year life, but can be mixed with the standard green without ill effects.
This is what I use.

Well it isn't quite as bad as $10.60 for a single strip. There are 4 strips in the package. To be honest I didn't look at the link you posted. I was in a hurry when writing my post, dinner was nearly ready. I was trying to help all here understand how important coolant chemistry is. And point out some sources for test strips.

Simi 60 said:

Geez they dont miss you there
Single strip for $10.60 / each
Vs
$25 for the castrol ones I linked to above and you get 50

Click to expand...

Having been through cleaning up a gel mess, not of my making. A flush may not be enough. It took hours if disassembly and rodding out to get the mess cleared up.

AusCan said:

Simi,
Sounds like your coolant is OAT type. (Organic Acid Technology). No need to test or add extra additives to this. Unlike standard coolants these don't use nitrites in their mix. It will last the 5 years the way it is.

Just make sure you don't mix your OAT type coolant with the standard green coolant with nitrites. It will gel and need a good flush and change.

Their is a 3rd type of coolant called HOAT (Hybrid Organic Acid Technology). It is similar to OAT with the 5 year life, but can be mixed with the standard green without ill effects.
This is what I use.

Click to expand...

Most engines that have replaceable cylinders need the DCA or SCA additives or similar.
That additive concentration needs to be maintained.
Just changing a filter that has the additive does NOt mean you are OK.
You need the testing strips to ensure the concentration is OK.

If too low you are not protecting the engine adequately.
If to high the coolant becomes alkaline and can do damage.

I test mine when I change coolant to ensure it is OK. After the first actual run I test it again for the same reason. SOmetimes more of the additive is used than expected.
If on the low side I may elect to change the filter or may add some directly from the bottle.

Even if you use the ready mixed coolant with the additives you still need to test to ensure the concentration is within the limits. Do not just assume the use of the ready mix is all you need to do.

None of this is hard, it just takes a few minutes to do.

My last comment is it is a lot easier to add more additive to raise the concentration if a bit on the low side. It is a BEEG PIA to lower the concentration if you install too much.

AusCan said:

Simi,
Sounds like your coolant is OAT type. (Organic Acid Technology). No need to test or add extra additives to this. Unlike standard coolants these don't use nitrites in their mix. It will last the 5 years the way it is.

Click to expand...

Are you sure about that?
I could find nothing to actually confirm that, not saying you aren't correct but would like evidence.
Testing strips, filters and coolant are cheap.
Wet liners and and and are not.

Just make sure you don't mix your OAT type coolant with the standard green coolant with nitrites. It will gel and need a good flush and change.

Click to expand...

Been there done that.
Got a pair of never done work cummins diesels back at the dirt house from another project.
I need to pull hoses off, rod out HE and give a good clean before doing whatever with.

On any engine that uses exposed cylinder liners the danger is caused by the cylinders ringing , vibrating , and causing a spot vacuum on the liner.

This can eventually form a hole in the cylinder, much ungood!

The "cure" is antifreeze that forms a slime on the cylinder wall, which is replaced as it erodes .

Like anything , too much can plug passages and coolers, to little the cylinder outside walls still get eaten.

This is why most engines recommend a good usually 2 part flushing , to remove the old slime and the installation of fresh at intervals .

Time in engine is sometimes used , not running hours. Read Da Book!

Just for info, the Cummins B series (like the 6BTA) are not wet lined and are not "coolant sensitive". You can use any "name brand" EG based coolant mixed 50/50 with distilled water. Change when servicing the raw water components which should not exceed 5 years, more like 3 depending on a number of factors. Obviously be careful if changing coolant types or brands, as this can lead to gelling issues.

This is info from Tony Athens and his staff.

Strips turned up today
1 second dip, 15 second wait and all good

I should have added that once I am satisfied about the initial charge concentration I check every 4- 6 months.