Which Coolant Do I Have?

[annihil8ted]

Hello! I'm about to do a coolant flush/swap and/or system clean this weekend. I've heard that mixing coolant colors is not a good idea but I'm not sure what was originally in there. This is a 98 TJ Sahara 4.0

Does this matter that much if I drain (don't plan to pull the engine block plugs) and refill with the wrong one?

And based on the photos, does a system clean seem like a good idea? My process is drain, flush, and fill with distilled + Prestone (should I add additional coolant?), drain, flush, and fill with Thermocure (do I need coolant here?), drain, flush, and fill with Zerex

 

[KennethS]

Drain and flush until the water comes out clear, then fill with whatever coolant you choose.

 

[annihil8ted]

Zer

Drain and flush until the water comes out clear, then fill with whatever coolant you choose.

Given that Zerex G05 is colorless, is there another HOAT that is good to mix for coloring?

 

[TheBoogieman]

Given that Zerex G05 is colorless

It's not.

 

[TheBoogieman]

Hello! I'm about to do a coolant flush/swap and/or system clean this weekend. I've heard that mixing coolant colors is not a good idea but I'm not sure what was originally in there. This is a 98 TJ Sahara 4.0

Does this matter that much if I drain (don't plan to pull the engine block plugs) and refill with the wrong one?

And based on the photos, does a system clean seem like a good idea? My process is drain, flush, and fill with distilled + Prestone (should I add additional coolant?), drain, flush, and fill with Thermocure (do I need coolant here?), drain, flush, and fill with Zerex

View attachment 446804

That hose looks filthy. Drain, fill with Thermocure and water, drive it for whatever the bottle says. Rinse and repeat until everything is clear. The Blue Devil stuff I used calls for 6 hours of driving. I did it twice to clean it.

 

[annihil8ted]

It's not.

Sorry, lightly colored; I misread somewhere that it's colorless but it's lightly orange/yellow right?

Yeah I definitely plan to flush clean; when I bought the TJ from the last owner, it looked like it had sat for years (still fired right up though and the oil change looked pretty fresh

 

[TheBoogieman]

Sorry, lightly colored; I misread somewhere that it's colorless but it's lightly orange/yellow right?

Yes. That's why I always use the Prestone All makes and models green stuff. The other antifreeze looks too must like rust to me.

 

[JEEPCJTJ]

The antifreeze I drained out into the bucket back in March 2022 is the Zerex G-05 I had used in July 2019.

The yellow stuff in the distilled water jug is the Zerex G-05 that I had just poured from that Zerex bottle that I bought in March 2022.

I did some double checking before I poured that yellow stuff in because I didn't flush anything that time. Turns out they're the same stuff and both had been available for quite a while until Zerex decided that making two different colors was too much, which kinda makes sense. What doesn't make sense is dropping production of the "peachy" color and sticking with the piss water.