2006 RAM 1500 Coolant question

[chebyrashka]

Hi all,

I am sorry if this is the wrong place to post - my questions are so basic that it's a bit embarrassing to ask. I really don't know much about cars at all, but need to figure out best steps to take.
I have 2006 Dodge RAM 1500, 5.7L I believe. It was bought used, from craigslist in 2020, and I have no clue exactly what coolant is in it right now. The orange coolant in the reservoir is half way between "full" and "add" lines, so I was going to add more. Manual recommends Mopar Antifreeze/Coolant 5 Year/100,000 Mile Formula HOAT (Hybrid Organic Additive Technology) P/N 5011764AB or equivalent. Of course I don't have that on hand. What I did find in the truck is open jug of Super Tech extended life 50/50, also orange in color, that my ex left there. It does not say anywhere on the bottle if it's OAT or HOAT, but after a little research it appears to be OAT. (I could be totally wrong) My ex does not remember for sure if he has added this Super Tech coolant/changed coolant since we bought the truck.
I read that both HOAT and OAT coolants can be orange, so color is not a good indicator, and that mixing them together can create a sludge... Sooo I am afraid to top the coolant off with the wrong stuff, since I have no idea if it's OAT or HOAT coolant in there (I am hoping it's HOAT like it suppose to be, but who knows).

Here are my questions:
1. Is there a way to figure out for sure what coolant is in the truck? May be some sort of chemical reaction test (I can get a bit of the stuff out of the reservoir for that)
2. If not, I am assuming the best way to prevent damage is take truck to the shop and do the radiator flush? Or can I just top it off with HOAT type and hope for the best?
3. Shop is using NAPA fluids. Should I bother ordering Mopar coolant instead? (looks like Mopar changed part number, I can't find 5011764AB for sale anywhere, but from one of the forums it appears 68048953AA would be the new part number - correct me if I am wrong) Found info that Zerex Hoat G-05 is basically the same stuff but twice cheaper.
4. In the meantime, is it safe to drive with coolant being half way between "full" and "add" marks? I might need to drive about 150 mi before I can get to the shop to flush the radiator.

If this topic was already discussed somewhere please point me to the right thread. Thanks for all your help!

 

[Daw14]

Get some distilled water and use that to top off with . No harm that way .

 

[chebyrashka]

It's pretty cold where I am and the truck is sitting outside under the carport. The 50/50 Super Tech coolant, for example, says it goes to -34. It got down to -37 here a few weeks ago... Considering the weather is it advisable to dilute the existing coolant with water?

 

[GTyankee]

Valvoline actually made the MOPAR HOAT

Whether you're topping off your radiator or doing a complete system flush, trust Zerex G05 Antifreeze/Coolant. Made for your car. Made by Valvoline.

G05 coolant is HOAT

 

[chebyrashka]

So since my truck is at 176K mi and manual recommends flushing cooling system every 60K mi + I don't know what coolant is in right now, I decided to make appointment and bring it for a radiator flush, bought 5 gal 50/50 Zerex G05 (system capacity is at 18.7 qt). Shop is going to use conditioner to flush it, I am not sure if they have a machine or just going to drain and flush with water.

But now I am reading horror stories about shops botching the process, introducing air into the system, about how difficult it is to remove all liquid out and there will be some left in the block and possibly thermostat (which kinda makes it pointless to flush, since my main reason for flushing is not wanting to mix different coolants). Also if they are going to flush with water and if some water left behind this will dilute the 50/50 mix, which is bad idea with temps like -37 outside. (based on research this can be mitigated with filling half of the amount with 100% concentrate and topping the rest with water, but I am having doubts shop is going to listen to my suggestions) I am so confused now and having second thoughts about this whole radiator flush at the shop thing.

Would it better to just wait till spring and try the DIY method with distilled water? I'll be driving with coolant filled 1/3 above the "add" line in the meantime. (it expands and measures 2/3 above "add" line when hot) I have a feeling have been driving like that for the last 3 years...