CarTalk.com Best of Deals Car Reviews Repair Shops Cars A-Z Radio Show

Jeep 2015 Coolant - Still safe?

Hi so I recently got a 2015 Jeep Wrangler Sport, and I noticed that the coolant was low after arriving with it from the dealer. I searched up in the user manual that the required coolant for this jeep is the MOPAR 10 Year/150,000 OAT formula. However when I went to get the coolant from NAPA autoparts the guy told me that the PRESTONE 50/50 predicated antifreeze/coolant 5 year/150,000 will do just fine since they did not have the MOPAR. I proceeded to add the new coolant and mixed it with the previous one. Which I believe was the pink coolant. Will the new green antifreeze harm my jeep? and should I just take it to get flushed? after searching online and seeing mixed reviews over this I am unsure on what to do. Many say that its harmful and others that it is completely fine to do that.

I would have returned to the dealer to find out why the coolant is low on a 5 year old car. Prestone, and other makers claim there “universal” coolants are fine mixed with anything. Others are adamant not to mix coolant types. I don’t have the expertise to know so I would not do it. The Mopar coolant is sold at your Chrysler, Dodge or Jeep dealer.

How much coolant did you add? Did you get a warranty? I would keep a close eye on the coolant lever in both the recovery bottle and the radiator.

You need to look at the label on the jug, I could not determine the coolant type from your description. Call them and ask prestone 888.269.0750

If it’s the coolant labeled as good for “all makes” that you added, it should be fine. I added some to the notorious GM dexcool in my Lesabre when I did a radiator flush 100k miles ago and have suffered no ill effects. I probably put in a gallon or so of the Prestone “universal” coolant. I’ve since done more work on the cooling system, and it’s now probably 90% prestone universal / 10% old dexcool in the system. In the future, I recommend (and plan to myself) stick with the manufacturers recommended coolant. But I don’t think you added enough for it to be a problem, even if it was a problem. I used dexcool (the manufacturer recommended stuff) in my truck when I flushed the system in it, just to be safe. But I’ve had no problems mixing the universal prestone with oem coolant, and haven’t heard confirmed stories of anyone who has.

You would use dexcool? not on my life watch, peak global is what I switched to, and sleeping well!

Yep. I figure if it was fine for the first 140k miles before I got the truck, should be ok for the next 50-100k I plan to keep it. I thought about switching to something else, but was afraid I wouldn’t get all the Dex out, then I’d have a mixture. Which I haven’t had a problem with either (dex plus universal), but horror stories abound.

If you only used a pint or so, no harm done. Generally if you mix coolants, expect the coolant to last as long as the shortest specified coolant. In other words, if you had put in a half gallon of Prestone 5 year/150k mile coolant into the Mopar 10 year/150k mile coolant, your coolant is now a 5 year coolant so you will need to change it next year.

Since this is a used vehicle, who knows what’s in it now. Suggest to drain & flush the cooling system & refill w/fresh coolant corresponding to the oem specs. As you say Jeep appears to recommends an OAT coolant for this engine, a version meeting Chrysler Material Standard MS-12106. I wouldn’t cheap-out on the coolant, as it comes in contact w/ many many surfaces inside the engine. Chrysler engineers have designed the engine so a coolant meeting those specs suffers no adverse effects from that coolant. Once the coolant is replaced and at the correct level you can monitor it over time to measure how much you are losing. Without any leaks it would be unusual to lose more than about a cup of coolant in 6 months/5000 miles.

pretty sure autocorrect issue here: the word should be “prediluted.”

Prestone 50/50
prestone