The Chrysler Minivan Fan Club Forums banner
1 - 9 of 9 Posts

·
Registered
Joined
·
71 Posts
Discussion Starter · #1 ·
Ok, 2014 Ram CV, threw a P0128 code on my way home. Context: Been 10-15 degrees F for 48 hours, warmed up to 32 degrees F late afternoon, noticed on the drive home it was running a bit colder than normal, assumed that was due to cold temps as this thing takes forever to warm up. At the end of 25 highway miles at 55mph, threw this code just as I was turning off the highway onto my road. After I parked it, checked the AF level, was 2-3 inches above the "MIN" mark, hose across the front (top) was hot, radiator itself was pretty cool.
Normally I would throw some AF in it, reset the code, and see what happens. But there is a complication. When the tranny was done in 2020, they drained the rad and refilled it. I dont know what AF they used, and the station closed right after they did the tranny due to the lockdowns. I know not to mix different types of AF, so my plan was to drain the system this year and fill it with the OAT (or HOAT, dont remember) stuff so I could then add AF safely.
The fluid I can see in the reservoiur is orange (not sure if that identifies it). I have two gallons of new Chrysler AF for it in the van. Tomorrow will be another 10 degree morning, so flushing not what I was wanting to do first light.
Also not sure if this means a bad thermostat issue, I was hoping to flush the rad then leave the cap off and see if any fluid moves, but they probably dont make rads like that anymore.
Any ideas on how I should proceed? I have a 25 mile trip to work and I dont want any overheat issues. Any quick tests I can do?
 

·
Super Moderator
Joined
·
28,481 Posts
Check the coolant level in your radiator, not the reservoir.

Orange is likely HOAT. HOAT can be yellow (Ford) or orange (Chrysler). Most Valvoline Zerex G-05 HOAT here is yellow., which is fine.
G-05 HOAT is compatible with many brands of coolant commonly available per

Mixing OAT and HOAT antifreeze doesn't seem to be a problem, Prestone (OAT) has been doing it for years. So has PEAK. A couple of safe antifreeze choices:
 
  • Like
Reactions: Mtfix20 and Scot_W

·
Registered
Joined
·
71 Posts
Discussion Starter · #3 ·
ok, first thing on the list at daylight. I will check also and see what the (new)AF I have is, I bought it for that vehicle, so whatever it is, its the correct stuff. Just scares me not knowing what is in there, the garage that did the job wasnt exactly top notch. So I am a bit hesitant to just add teh new stuff in without draining out the old.
 

·
Registered
2013 Dodge Grand Caravan
Joined
·
3,517 Posts
Messing with coolant in 10 degree weather?! F*@& that! A thermostat and flush can wait until it's a bit warmer. Top off with a universal coolant since you're unsure if it's the good stuff or evil Dexcool. I know Prestone makes a yellow universal coolant that mixes with everything, says so right on the label and I've put it to the test. If you're low, you know you have work to do when it gets warmer. If not, it could really just be the cold.

To prevent losing so much heat to wind at highway speeds. Get a sheet of cardboard and block off about a third to half of your radiator. Don't do more than half unless you live and work right off the highway and won't be in city traffic for more than a few minutes. I wouldn't do more than a third if you plan on going to any drive-throughs. You should monitor your temps regardless. Higher than 210 means you need to trim your sheet (your goal is 203). If you size it just right, you can get it to hold itself in place between the power steering cooler loop (bottom), upper support bracket, and the radiator. A sheet folded in half vertically that fits in the gap around the latch will unfold to cover roughly half of the radiator.

I'm currently running this in 30-40 degree weather with no thermostat because of engine troubles. I get up to about 180 in the city and I'm lucky to maintain 145 on the interstate. I disabled P0128 temporarily in my tune, but I did this to prevent a P2181 which makes the PCM freak out and think there's an issue with the sensor ground circuit... which is shared by the throttle body and makes the throttle control error light come on. Ah, the joys of rigging it. :p
 

·
Registered
Joined
·
71 Posts
Discussion Starter · #5 ·
With the top hose hot, I thinking the thermostat is probably ok, am I thinking that right? I will pick up one anyway, just to have a spare with me, but not in a hurry to change that out right now unless there is a real possibility of a failure.
 

·
Registered
2013 Dodge Grand Caravan
Joined
·
3,517 Posts
As long as you're getting in the ballpark of 200 and then dropping, the thermostat is working. It's just there to speed up warm up. It's very possible that your code is just weather related. Before I did the cardboard, I was dropping from 140 in city to below 100 on the interstate with my thermostat removed, and it's 30s/40s here. If yours was stuck full open in 10 degrees, you'd never see the needle get past 1/4.
 
  • Like
Reactions: Jeepman

·
Registered
Joined
·
71 Posts
Discussion Starter · #7 ·
Cold weather pretty much the case I believe. I opened up the radiator and fluid is visible in the neck, so low fluid was not the issue, then decided to pull the t-stat just to check on it, looks fine, side benefit I drained alot of AF out, clearly orange stuff, so I think I am ok with what the parts store said I needed (Mopar concentrate coolant MS90032 "embittered" , looks like its OAT) although the container says to still "check owners manual for specified antifreeze type". Never saw an owners manual with this van other than a CD. I am going to Advance auto when they open and pick up a thermostat, but I will keep the old one as it looks fine.
 

·
Super Moderator
Joined
·
28,481 Posts
How to Fix P0128 Engine Code in 3 Minutes [2 DIY Methods / Only $7.34] :)

ECT sensor = CTS sensor (coolant temperature sensor)

Mixing OAT and HOAT antifreeze doesn't seem to be a problem, Prestone (OAT) has been doing it for years. So has PEAK. A couple of safe antifreeze choices:
 
  • Like
Reactions: Scot_W

·
Registered
Joined
·
71 Posts
Discussion Starter · #9 ·
Put a new t-stat in and refilled, reset the codes, just drove it to work (25 miles highway) no codes, temp dead center of the gauge. heat works good. will recheck the bolts when i get back home later. kept the old t-stat as this new carquest one may not last as long.
I think it had to do with the cold road temps that day, but with another round of zero degrees coming, I thought this was the best solution.
 
1 - 9 of 9 Posts
Top