Coolant Changes - Latest Thought?

[Passages]

My mechanic and the "experts" at RPM Diesels in Fort Lauderdale can not agree. Since my boat never sees cold weather, freeze protection is not essential.

Currently, my 8-92TA's are charged with Dexcool. Everyone is in agreement that that stuff is not good for Detroits.

My mechanic insists that after a proper flush, I need to recharge coolant with Ethylene Glycol (PowerCool) and stabilizers (NorCool 2000). Dilute with distilled water.

RPM Diesel guy thinks I only need stabilizer. Says Norcool is obsolete and PenCool is the latest greatest. Oh, and don't waste money on distilled water because Fort Lauderdale water is clean enough for Detroits. (??? FLL water comes out of the tap with a yellow tint)


Who's right?

(ps: It's true that NorCool is now rebranded as PenCool)

[Boatsb]

You have some cool ideas.

So just to be clear. You want more opinions on a subject that has many levels of interpretation.

I use napacool and distilled water. No issues and my 1966 engines seem to like it.

Water is superior to antifreeze for heat transfer. The Napacool has the addictive package so I'd recommend you go that way but what do I know?

[racclarkson@gmail.com]

I’m now 30% fully formulated Chevron (Power Cool) equivalent and distilled water after Penray flush. Why on God’s green earth would a mechanic be against $0.89/gal distilled water?

[Passages]

I’m now 30% fully formulated Chevron (Power Cool) equivalent and distilled water after Penray flush. Why on God’s green earth would a mechanic be against $0.89/gal distilled water?

My mechanic is for distilled water. It's RPM Diesel that thinks the yellow tea that comes out the tap is OK.

[rsmith]

In non freezing environment Detroit recommendation is water only with a anti rust additive
RTFM

[oscarvan]

In non freezing environment Detroit recommendation is water only with a anti rust additive
RTFM

Hmmm, that's not the way I read their publication on the matter. It is "approved" not "recommended" I have it in a PDF file and will be happy to send it to anyone.... Here's the important part:

[jim rosenthal]

I'd use distilled water- every engine manual I've ever read favored distilled water over tap water, no question about it. As far as the additive to use, I'd use what your mechanic recommends. A 50/50 blend of distilled water and AF is what I use here in MD, and although it doesn't get as hot here as it does in FL, we do get water temps in the 80s.

I think your mechanic is right, and you should follow his recommendations. As to RPM diesel, I have no idea why anyone would ever recommend tap water being used in the cooling system of an engine. Florida tap water, as you pointed out, is not exactly five-star quality from all I've heard and experienced.

[madhatter1]

For the 92 series the powercool and equivalents is required to prevent damage to block and wet liner from I think boiling that can over time create problems. Just what I was told and also read. My mechanic says to use the right coolant although he did not specify a brand. We won’t be cleaning heat exchanger until next year.

[rsmith]

Hmmm, that's not the way I read their publication on the matter. It is "approved" not "recommended" I have it in a PDF file and will be happy to send it to anyone.... Here's the important part:

Approved vs recommended seriously? Would they recommend something they didn’t approve?

[Passages]

First a shout out Thank You to Oscarvan for emailing the DD guidelines on cooling systems.

Been doing a bunch of reading.

First - All traces of Dexcool needs to be flushed from Detroits.
To accomplish that, we'll remove the core and manually pressure wash the interior of the Hx cavity. This will be followed by 2 cycles of flush with tap water at the dock.
After the 2nd flush is complete, I'll top off with a "Water & Stabilizer Only" mix. This is Pencool 2000 and distilled water.
The W&S mix will remain in the system for a couple trips where I can be assured all remaining traces of Dexcool are suspended.
After that, I'll drain the water only mix, and replace it with distilled water & Pencool 3000 & Powercool (ethylene glycol) at 30%.

Side note - Pencool 2000 is used for a water/stablizer mix while Pencool 3000 is for water/ethylene glycol/stabilizer mix. Since Dexcool is so incompatable with other chemistry's, this is the safest way to purge and restore my coolant.