Which antifreeze to buy

[dieselpilot1969]

So what kind of antifreeze is best to use in an 03, Ive heard of fleetguard 50/50premix (spendy stuff), any others work? And where in the heck can I get de-mineralized water?

 

[RobbieH]

Do you need antifreeze already???



You gotta use the Hybrid Organic, it tells you in the manual. They call it HOAT. Zerex G-05 is compatible.



Mix 50/50.



According to the manual, replacement takes place at 100,000 miles. If you are there already you drive more than me!

 

[dieselpilot1969]

well in all honesty the reason I asked is I had the leaky head plug thing fixed on the truck and popped the radiator cap and noticed some gelling from the dexcool, did not care for that so I am going to replace it probly next week

 

[RobbieH]

Dexcool is totally the wrong stuff.

 

[dieselpilot1969]

thats what the dc service said was the factory fill

 

[RobbieH]

HAHA! You gotta love the dang service people at the dealership. They see something that resembles pink and they immediately guess Dexcool. The color of the factory fill is actually "orange", but I'd debate that too.



You might look at this:

https://www.turbodieselregister.com/forums/archive/topic/82475.html

 

[Rosco]

I've seen Rotella pre-mix antifreeze at Pep Boys but I don't know if it meet's our spec's.

 

[dieselpilot1969]

so for a low silicate antifreeze, whats a good # or percent of silicate?

 

[rbattelle]

My opinion

Call me old-fashioned, but I just don't trust that HOAT stuff. And as far as I'm concerned "100,000 mile coolant" is just like "lifetime-lubricated U-joints".



I plan to have the local Cummins shop flush my system in the Spring (at the 1 year mark) and refill with Fleetguard premix. I can think of no reason why HOAT would be required. I believe the only really important thing is to use distilled water to help keep mineral deposits at bay.



By "de-mineralized" they mean distilled. It shouldn't be hard to find a source for distilled water. Or, if you decide to go with the Fleetguard premix, it's premixed using distilled water.

 

[rbattelle]

One other thing

Also, the service manual states the antifreeze must be glycol-based. That tells me you can use either ethylene glycol or propylene glycol. I like ethylene better.

 

[Tony T.]

(HOAT)

(Page 306) of the 2003 Owners Manual shows a (caution note). Mixing of coolants other than the specified (HOAT), may result in engine damage that may not be covered under the new vehicle warranty, and decreased corrosion protection. Also states, This vehicle has not been designed for use with Propylene Glycol based coolants. Use of Propylene Glycol based coolants is not recommened.

 

[rbattelle]

Good catch on the Propylene glycol, Tony!



As far as the "mixing of coolants other than the specified HOAT" statement, I take that to mean "if you're topping off your coolant, don't use anything but HOAT", which is good advice. However, if you're going to flush the system clear of HOAT, then put in regular Ethylene Glycol, you're perfectly fine.



What does everyone else think?

 

[RobbieH]

I looked in the Factory Service Manual. I will make a long story short.



CAUTION: Use of Propylene-Glycol based coolants is not recommended, as they provide less freeze protection and less corrosion protection.



The use of Mopar coolant (MS-9769) or equivalent is recommended. This coolant contains organic corrosion inhibitors (HOAT) and offers the best cooling without corrosion when mixed 50% coolant and 50% distilled water.



The above paragraph (paraphrased) is repeated 3 times in 2 pages.



Pages 7 - 36 and 7 - 37 in the 2003 FSM.



Page 7 - 38 starts with:

CAUTION: Do not use coolant additives that are claimed to improve engine cooling.

 

[RobbieH]

Originally posted by rbattelle

Good catch on the Propylene glycol, Tony!



As far as the "mixing of coolants other than the specified HOAT" statement, I take that to mean "if you're topping off your coolant, don't use anything but HOAT", which is good advice. However, if you're going to flush the system clear of HOAT, then put in regular Ethylene Glycol, you're perfectly fine.



What does everyone else think?

Well, since you asked here is the direct paragraph quote. I found it 3 times. I think they were trying to make a point.



The use of aluminum cylinder blocks, cylinder

heads and water pumps requires special corrosion

protection. Only Mopar Antifreeze/Coolant, 5 year/

100,000 Mile Formula (ethylene-glycol base coolant

with corrosion inhibitors called HOAT, for Hybrid

Additive Technology) is recommended. This coolant

offers the best engine cooling without corrosion when

mixed with 50% distilled water to obtain a freeze

point of -37°C (-35°F).

 

[rbattelle]

Robbie,



We don't have aluminum cylinder heads or blocks. We have aluminum water pump impeller (I think) and of course an aluminum radiator and heater core, just like every other vehicle on the road. I submit the following quote from the product literature on Fleetguard premix EG coolant:



FLEETGUARD ES COMPLEAT™ EG Antifreeze/Coolants are Extended Life formulations that

contain Ethylene Glycol base fluids and are designed specifically for Extended Service use in heavy-duty

diesel engines. ES COMPLEAT™ contains conventional heavy-duty chemical inhibitors and organic corrosion

inhibitors that provide enhanced diesel engine liner pitting protection and eliminates hard water scale

deposits. ES COMPLEAT™ products are formulated with the highest liner pitting protection available in the

marketplace, with low TDS and silicate levels. ES COMPLEAT™ is specifically designed for use with ES

Slow Release coolant filters or liquid ES Extender to provide simplified coolant maintenance while extending

coolant service intervals to 12 months or 150,000 miles. ES COMPLEAT™ can also be used in standard

service maintenance intervals with the use of SCAs and standard coolant filters.

ES COMPLEAT ™ EG CONCENTRATE mixes readily with clean tap water or demineralized water, while

ES COMPLEAT™ EG PREMIX is formulated with demineralized water and is ready to use. Both EG coolant

products are low silicate, contain a full charge of heavy-duty chemical inhibitors, and are compatible with ES

Coolant chemical filters and conventional SCA’s. ES COMPLEAT™ EG antifreezes are universal products

highly recommended for use in all Cummins and similar types of heavy-duty diesel engines, and also for use

in automobile and light duty applications.



Notice in the 1st paragraph they mention "organic corrosion inhibitors". Maybe they're refering to HOAT?

 

[DPKetchum]

I wont change mine for at least three years. Good green stuff is a three year fliud. You can overdo some maintance. New coolant fliuds are designed with a LOT longer life from years back. Same as oils/gear oils etc.

 

[rbattelle]

DP,



Normally I would agree, but I've seen that HOAT stuff turn to jelly in under 3 years. I know, everyone's got a "I knew a guy who had an uncle whose coolant turned to jelly", but I really mean it!

 

[dieselpilot1969]

check this out, my truck was only seven months old in this photo. This will back up the turns to jelly thing!

 

[RobbieH]

rbattelle,



You have to take what I posted in context. I was posting from the FSM. I'm just saying, you shouldn't try to run the 'wrong' stuff.

 

[RobbieH]

DieselPilot,



Did you not say earlier that you had Dexcool in there?



That would totally negate your complaint about the factory fill?