Dirt Hammer

What coolant have you switched to in your JK model Jeep? (3.8 and 3.6 engines)

I know there is a rainbow of colors and OAT and HOAT and IAT coolants out there.

I drained and refilled my 2015 JK with old school green IAT 50/50 mix earlier this year, going to flush the block and radiator again soon to make sure I can get most of the HOAT coolant out of the system. Refill with IAT green 50/50 mix.

Besides extended service life I can't see any reason to run the OAT or HOAT type coolant, and it seems that the HOAT coolant is causing some of the debris in the cooling system and clogging up heater cores.

Rednroll

I had to do some coolant system work on my wife's Jeep Renegade which uses OAT this weekend, and not being able to just drop into any store and pick up a jug of coolant is definitely an inconvenience. When I was looking at the jugs of coolant on the shelves at the local retail stores, there seemed to be so many different flavors being sold under the same brand besides HOAT/OAT, it made my head spin.

I haven't ventured outside of the Mopar factory box but interested in what others have to say.

I'm going to say HOAT coolant causing debris in the cooling system and clogging up heater cores is likely some made up internet speculation rumor. Coolant doesn't cause sand to form.

Dirt Hammer

Some of the reports were that the HOAT was separating from the coolant (chemical reaction). For me besides extended service life I can't see why old school coolant would not work. It's ready available at all stores and has been around forever and works. I'm going to try an flush the engine block of all coolant and radiator, and go back with IAT green 50/50 mix coolant, I'm ok with changing it every few years.

resharp001

I've just stuck with the Mopar OAT on my 2013. Big part of that though was 1) I really didn't care to worry about getting every last bit of the old flushed out, and 2) it doesn't cost THAT much more than another good quality offering. I use Zerex in two Fords that I own for the kids. I'm kinda surprised by the cost of that stuff at ~$17/gallon. If I recall, I pay about $23/gallon for my OAT concentrate at the dealer.

EHarris

I stuck with the HOAT from Quadratec and mixed it myself. Zerex 50/50 if I needed some in a pinch.

Subscribed to see how this goes. Very interested. I've heard both ways. Green clogs. Orange clogs. This will be a good test.

Riptide9

Take the info with a grain of salt but I wouldn't mix that shit in my rig

https://wayalife.com/showthread.php/...e-Your-Engine!

And here is a TSB from Chrysler (note the Caution):


TSB - 07-004-12 REV. A
SUBJECT:
Attention! Release Of New Engine Coolant Organic Additive Technology (OAT)
MODELS:
2013 (D2) Ram Truck (3500 Pick Up)
2013 (DD) Ram Truck (3500 Chassis Cab)
2013 (DJ) Ram Truck (2500 Pick Up)
2013 (DP) Ram Truck (4500 / 5500 Chassis Cab)
2013 (DX) Ram Truck (Mexico)
2013 (DS) Ram Truck (1500)
2013 (FF) Fiat 500
2013 (JC) Journey
2013 (JK) Wrangler
2013 (JS) Avenger/200
2013 (LC) Challenger
2013 (LD) Charger
2013 (LX) 300
2013 (MK) Compass/Patriot
2013 (PF) Dart
2013 (RT) Town & Country/Grand Caravan
2013 (WD) Durango
2013 (WK) Grand Cherokee
2013 (ZD) Viper
NOTE: This bulletins applies to all vehicle listed above for every engine application
EXCEPT the 2013 MK equipped with the 2.2L Diesel engine (sales code ENE)
and the JC vehicle equipped with the 2.0L Diesel engine (sales code EBT).
NUMBER:
07-004-12 REV. A

GROUP:
Cooling

DATE:
November 03, 2012

DISCUSSION:
Chrysler Corporation LLC. has released a new engine coolant for the 2013 model year
vehicles and beyond, for all engine applications except the ones listed in the note above.
This new coolant is an Organic Additive Technology (OAT) (
Fig. 1). OAT coolants have a
service interval of 10 years or 150,000 miles. For heavy duty truck and extreme duty cycle
applications refer to the Service Information or Owner's Manual for proper maintenance
schedules.

CAUTION: Vehicle Damage may occur if dissimilar coolants are mixed!
Coolants of different technologies are not compatible nor interchangeable (OAT, HOAT or
IAT).
Mixing these coolants could result in:
• accelerated corrosion within the engine and cooling systems.
• the coolant having an ammonia smell.
• debris (particles) floating in the coolant.
Further inspection by the technician may find corrosion in the system. This could show up
as aluminum pipes turning black in the coolant system, engine overheat, or leaks in the
coolant system.

NOTE: If OAT (MOPAR P/N 68163848AA Purple) has been Mixed with HOAT (MOPAR
P/N 68048953AB Pink Or Factory Fill HOAT Orange (
Fig. 2) or (Fig. 3)) or any
other coolants have been mixed, it will be necessary to flush the cooling

system.

Rednroll

Yeah, that sounds like some B.S. redneck diagnosis. Many of us have the 3.8L engine which uses HOAT and have been using it for well over 200K miles. The only chemical reaction I am aware of is in regards to HOAT is that if HOAT gets mixed OAT. Mixing them will cause a chemical reaction and cause gel to form within the cooling system.