Help....mixed Hoat with OAT

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I have a 2017 Chrysler Pacifica and did an oil change yesterday.
I noticed the antifreeze reservoir was a little low so I topped it off.
I had a jug of G-05 HOAT and thought that it was the proper antifreeze to use.
Today I read that Chrysler switched to a OAT antifreeze and you should not mix them.

I probably only added a few cups of the G-05......do you think I will have any troubles from mixing the two ??
 
If you just topped off the overflow bottle you are fine, but I would pull up on the overflow bottle which just sits in slots on the radiator, disconnect the hose going to the Rad-Cap neck and pour out the bottle and then refill with OAT. That's not enough HOAT to cause any problems.

I accidentally did the same thing to my Journey as I had left over HOAT from my dad's 2012 Caravan which required HOAT and I poured that into my Journey overflow bottle when it was low and then read the manual and realized I goofed because my Journey took OAT. I just poured out my bottle and refilled with OAT and it was fine. I did drive about 1,000km (600 miles) with it that way though.

The coolants are compatible with each other but the problem is HOAT can cause problems in OAT only systems if used instead because of it reacting with materials found in the cooling system if you were to fill the entire system with HOAT. OAT coolant can be used in place of HOAT but HOAT can't be used in place of OAT. (Again a little won't hurt anything, but refilling the entire system with HOAT will not have the same anti-corrosive effectiveness over time, you won't end up with Dexcool type sludge or anything though)

It was stupid of Mopar to use the same colour for both HOAT and OAT when they sound similar and could easily be mixed up. Also doesn't help that it looks orange as your are pouring it but purple in the overflow bottle.

You are good to go, just dump the overflow bottle and refill.
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Originally Posted by zrxkawboy
I don't believe those two coolants are compatible. I would flush it.

HOAT contains OAT in it. HOAT = Hybrid Organic Acid Technology. OAT = Organic Acid Technology This is why you can use OAT in a HOAT system but can't use HOAT in an OAT system.
It's due to the compatibility of the materials in the cooling system not playing nice with HOAT if they were designed for OAT but will play nice with OAT if they were designed for HOAT.
 
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Originally Posted by fins
I have a 2017 Chrysler Pacifica and did an oil change yesterday.
I noticed the antifreeze reservoir was a little low so I topped it off.
I had a jug of G-05 HOAT and thought that it was the proper antifreeze to use.
Today I read that Chrysler switched to a OAT antifreeze and you should not mix them.

I probably only added a few cups of the G-05......do you think I will have any troubles from mixing the two ??

A lot of horror stories on Jeep and other Chrysler forums from the two being mixed in error. They are not compatible, and bad things have happened, even with dealers topping off overflow tanks with the wrong coolant during PDI checks. I'll refrain from commenting on what I would do, but would strongly suggest you read up on it, then decide.
 
How does mixing one chemical (HOAT) with another chemical (OAT) when both contain the same (OAT) coolant cause problems? If the whole system was filled sure because the HOAT isn't compatible with materials in the system and over a period of time can cause a problem but the small amount added by by topping off the overflow bottle isn't enough over the gallons of fluid in the whole system to cause any problem if he simply empties out the overflow bottle and refills it with OAT. Even if some of it was sucked into the system.

I would argue (not with you demarpaint) but with the forums that either we aren't getting the whole story or they are embellishing the story in this instance because of something stupid they did and didn't want to admit to like using some one size fits all coolant that claims to meet the OAT spec or some cooling system additive. There is OAT in both Mopar formulations of HOAT/OAT so it makes no sense that HOAT wouldn't be compatible with OAT in terms of mixing them together accidentally (not in terms of cooling system material compadibility.) In the 2012 Caravan it says you can use HOAT or OAT coolant but that it was originally filled with HOAT, it makes no mention of having to completely eliminate one coolant by flushing before adding the other either. In my 2018 Caravan it says OAT only coolant only because of material changes somewhere in the system.

Further I did this myself and drove 1,000km (600 miles) which is more than enough time for the radiator to expand into the overflow bottle and then suck back this mixture into the system as it cooled down and my Journey had no issues. (60,000 miles later)
 
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I believe you have misunderstood ...OAT is not an ingredient ("contains OAT").

I have no desire to argue. Chrysler service manuals warn against mixing the two...that's enough for me.
 
Originally Posted by zrxkawboy
I believe you have misunderstood ...OAT is not an ingredient ("contains OAT").

I have no desire to argue. Chrysler service manuals warn against mixing the two...that's enough for me.

Not because they are incompatible with each other but because using HOAT in an OAT system won't offer the lifelong corrosion protection for certain materials. THAT'S IT. Not because they will turn into Dexcool sludge monsters.

Further the 2012 Caravan manual said you could use either OAT or HOAT without flushing. How would that be possible?
 
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Originally Posted by StevieC
If you just topped off the overflow bottle you are fine, but I would pull up on the overflow bottle which just sits in slots on the radiator, disconnect the hose going to the Rad-Cap neck and pour out the bottle and then refill with OAT. That's not enough HOAT to cause any problems.


This is not correct. On the new gen Pacifica, the "overflow" bottle is a pressurized member of the coolant system.
 
Originally Posted by StevieC
If you just topped off the overflow bottle you are fine, but I would pull up on the overflow bottle which just sits in slots on the radiator, disconnect the hose going to the Rad-Cap neck and pour out the bottle and then refill with OAT. That's not enough HOAT to cause any problems.
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If you did *not* drive it and if you simply topped up the overflow tank: it did not circulate. Simply empty the overflow tank, clean it and replace with proper coolant. I did the same once, but with windshield wiper fluid!....
 
HOAT is a combination of OAT and IAT (IAT is traditional green coolant)

OAT is simply without IAT.

Nothing disastrous will happen, just less corrosion protection if you use HOAT where OAT is called for. Seriously folks here need to calm down. It's not DEXCOOL.
 
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Originally Posted by StevieC
How does mixing one chemical (HOAT) with another chemical (OAT) when both contain the same (OAT) coolant cause problems?


They don't necessarily contain the same organic acids. OAT is not an "ingredient," its a class of coolants based on organic acids for corrosion prevention. Not all organic acids behave exactly the same, and when you throw in the non-organic components that exist in a HOAT, you can get all sorts of weirdness, like solids precipitating out of the liquid solution. The organic acids picked for a HOAT, such as G-05, are known to be compatible with the inorganic components used in it (silicates, nitrites, etc.) The organic acids used in the pure OAT might be incompatible with those inorganics found in the HOAT, causing them to drop out of solution. Or they might not play nice with the other organic acids. Without knowing the exact chemicals involved, its impossible to say. Well, even then it would be impossible for me, my daughter the chemist might be able to tell you what happens.

Bottom line, the safest thing is to drain and refill.

Originally Posted by StevieC
HOAT is a combination of OAT and IAT (IAT is traditional green coolant)

OAT is simply without IAT.


Simply not true. You cant just mix conventional IAT with DexCool and have a coolant that behaves the same as G-05 or another HOAT.
 
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I know OAT is not an ingredient what I was getting at is that HOAT contains OAT along with IAT. It's a combination of the two types of coolant in MOPAR's case. So mixing HOAT (OAT+IAT) with OAT = FINE in terms of compatibility just not with the materials in his system long term and when I say not with the materials I mean the whole system being filled with this mixture and not just a minuscule amount that may have made it from the overflow bottle to the circulating coolant.

If it was the whole system filled with HOAT, or it were Dexcool and something else I would advise a complete system flush and refill but this isn't the case here.

You are also forgetting I did this myself and drove it like that far longer than he did and my cooling system was just fine 60,000 miles later.
 
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Originally Posted by StevieC
If you just topped off the overflow bottle you are fine, but I would pull up on the overflow bottle which just sits in slots on the radiator, disconnect the hose going to the Rad-Cap neck and pour out the bottle and then refill with OAT. That's not enough HOAT to cause any problems.

(Edited out for space)

You are good to go, just dump the overflow bottle and refill.
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This is what I was about to recommend. You said it was yesterday that you did this. As long as the vehicle has not been driven much, I doubt any appreciable amount of it has really left the overflow. Dump the overflow and refill.
 
Originally Posted by StevieC
Originally Posted by zrxkawboy
I believe you have misunderstood ...OAT is not an ingredient ("contains OAT").

I have no desire to argue. Chrysler service manuals warn against mixing the two...that's enough for me.

Not because they are incompatible with each other but because using HOAT in an OAT system won't offer the lifelong corrosion protection for certain materials. THAT'S IT. Not because they will turn into Dexcool sludge monsters.

Further the 2012 Caravan manual said you could use either OAT or HOAT without flushing. How would that be possible?

Do a search on the www, the outcome of mixing the two is very bad, and can be very costly to fix. The outcome of the mix is a mess, which I've seen first hand in a family member's Caravan.
 
Because it's on the internet it must be true right?

Furthermore I will say again. HOAT = OAT + IAT ............. OAT is without IAT. It's not chemically possible for it to be incompatible with each other and to cause a problem. It's why OAT can be used anywhere HOAT can but not the other way around because of material compatibility with the IAT in HOAT not being compatible in OAT only systems. It has nothing to do with the chemical itself compatible with each other.
 
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Maybe the confusion is with mixing things with NOAT type which is Dexcool. That is disastrous because of the Nitrite not playing nicely with other substances.
 
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