Which coolant change interval should I follow? manual or product label?

[leoblack9]

I have a 2017 Isuzu d-max, 3.0L diesel engine, with oem intervals saying that i change coolant (using genuine Isuzu coolant) every 2 years regardless of distance.

One of the recommended fluids in the manual, Havoline XLC, specifies that it could be used for 5 years of 150k miles/250k kilometers.

I'm torn whether I should adhere to the 2 years interval or I stick to what Havoline claims. Any advice appreciated, thanks.

 

[Greasymechtech]

Manual!

 

[Gimpy1]

The manual.

 

[Oro_O]

Your manual is probably written for your climate, and specific to the Philippines, where two years would be safer.

Milder climates can go much more with modern coolants.

 

[2EHA]

XLC is also known as dexcool. it is usually stated as a 5 year coolant by gm and a 10 year coolant by ford

 

[leoblack9]

Your manual is probably written for your climate, and specific to the Philippines, where two years would be safer.

Milder climates can go much more with modern coolants.

With the advancements of modern coolant tech I wondered if I could go more than 2 years since it reminds me of having those old school IAT coolants. Heck modern PHOAT coolants are claimed to last for 10 years!

XLC is also known as dexcool. it is usually stated as a 5 year coolant by gm and a 10 year coolant by ford

Yes, it specifically states that the coolant must have a GM6227M certification. I just wondered if I could go with their claim for 5 years for my japanese light truck.

 

[Oro_O]

Yeah, I would *think* so. But whereas most all modern makers say to go five years on the initial fill, they are distinctly NOT saying that. I have to wonder if they know something we do not...

This caught my eye because I also have an Isuzu (not a d-max, which unfortunately we do not have here). It is an older gas model and I run a modern pHOAT in it now for longer intervals. I would perhaps split the difference and not do a complete system flush, but just remove the radiator petcock (or lower radiator hose if your radiator doesn't have a petcock) and do a drain/fill vs. a full system flush. That would substantially renew the inhibitor content of the coolant with a lot less effort. This is what I do - albeit on a longer schedule than two years.

 

[leoblack9]

Yeah, I would *think* so. But whereas most all modern makers say to go five years on the initial fill, they are distinctly NOT saying that. I have to wonder if they know something we do not...

This caught my eye because I also have an Isuzu (not a d-max, which unfortunately we do not have here). It is an older gas model and I run a modern pHOAT in it now for longer intervals. I would perhaps split the difference and not do a complete system flush, but just remove the radiator petcock (or lower radiator hose if your radiator doesn't have a petcock) and do a drain/fill vs. a full system flush. That would substantially renew the inhibitor content of the coolant with a lot less effort. This is what I do - albeit on a longer schedule than two years.

How long do you run your pHoat coolant? and how did you transition from the old IAT coolant to modern coolant?

I'm also on that fence, since mine originally came with green coolant from the factory I plan to do 2-3 flushes with pure distilled water before putting in the orange havoline dexclone in it. The dealer just pulls the petcock from the radiator and drains the old fluid. Add 8L of coolant and calls it a "flush."

 

[Donald]

Manual!

+1

 

[PandaBear]

When in doubt follow the shorter one

 

[Krieg]

I would follow the Owner's Manual. Engineers are smarter than me.

 

[RyanY]

Email the coolant manufacturer and describe your specific situation. Then, if they recommend a longer service than the owner's manual, save that email in case the coolant fails.

 

[ARB1977]

What I don’t get is my book states 10 years or 100K for the first change. Then 5 years or 50K after that. It’s the same coolant.

 

[circuitsmith]

What I don’t get is my book states 10 years or 100K for the first change. Then 5 years or 50K after that. It’s the same coolant.

They assume you doing a simple drain and fill, leaving about half the old coolant in.
My previous Tooyota manual said a similar 7 years on the original fill, but I did a D&F at 5 years and 10 years.