Antifreeze question ???

[rameye]

I'm getting ready to do a flush and fill, the more I read, the more confused I get about the type of antifreeze to use.

Can I use dexcool or equivalent? and if I do, do I need to put in a diesel additive to prevent cylinder cavitation??

Thanks for the help

[DmaxMaverick]

I suggest using Dexcool if that's what you are removing. Problems you hear about Dexcool usually involve improper use, or mixing with other types. You can use it if you do a good flush with distilled water, and use distilled water for your 50/50 fill. Distilled water should be used, no matter which coolant you choose. Be sure to bleed all the air out. I've used Dexcool successfully for years.

Another option is Evans NPG. Contact Greg at www.lubespecialist.com/ (http://www.lubespecialist.com/) for details on that. Expensive, but has its advantages.

The additive is not necessary in any GM Diesel engine, regardless of coolant. Cavitation has never been an issue with them. Some people use it, but it's not necessary.

[rameye]

Got it..Thanks

[ucdavis]

Air bleed is important to avoid cavitation & corrosion which is apparently accelerated w/presence of air in DexCool & absent to the point of near permanence w/good attention to the air bleed. Air bleed screw is on the crossover.

[damork]

Rameye,
I flushed my 95 over 100,000 miles ago and refilled with Dexcool. I also switched my wife's Explorer and before that she had an old BMW. All continue to work just fine and I don't have the silicates building up in the cooling system.

There is a lot of controversy out there, but if you do it right and really flush it out good, you should not have problems. I know some manufacturers are not clear on what you should do, so I chose to find out myself and haven't seen a downside yet. We've successfully logged over 200,000 miles with Dexcool in vehicles that didn't come with it.

A note of caution - I used distilled water exclusively - to flush AND to fill. If you've ever run a distiller you'll see what kind of junk is really in tap water.

[eracers999]

Cavitation and corrsion as some call it is electrolisis. Diesel engines, gas engines, all radiator and heater cores, dont care who's it is are all suseptable to electrolisis. Its nothing more than the a/f gradually turning acidic. The DCA additive is a great counter measure for the dex cool. Once the DCA is used then you can keep a eye on it with the test strips, as dex cool will not strip test new out of the bottle. Just a point to make, all of the 00 and 01, 3800 series 2 engines that i have put intake sets on that still have the factory fill of dex cool and are well with in the mileage window show mild to moderate but detectable electrolisis. Every vehicle i own has DCA in it and i have 7, 5 gas 2 diesel. And if i were a d max owner id have it in that too. Just couldent stand to one day see the pock marks in those aluminum heads.

Kent

[rameye]

Thank-you to all...I was under the impression that the cavitation occurred as the cylinder fired off. I assumed that it was the intense vibration that resulted, caused a momentary vaccum condition which caused a low temperature boil and that the additive helped prevent that.

Know all I have to do is figure how to get the lower hose off the radiator....what a pain in the @$$!

Thanks again

[DmaxMaverick]

The condition Kent speaks of is very different than your original concern regarding the additive.

While his recommendation has merit, it is not going to help with cavitation, if you have that issue. Cavitation causes cracked cylinder walls without concern to the acidic level in the coolant.

Diesel engine cylinder wall cavitation is caused by surface boiling and outgassing of the coolant at the outer surface of the cylinder wall. The violent Diesel combustion processes causes the cylinder wall to pulse, or "flex". This flex results in a rapid rebound of the cylinder wall, causing a "vacuum" at that point. That vacuum causes outgassing and surface boiling of the coolant, resulting in etching of the surface from the air bubbles peening the cylinder wall. The end result is a weakened cylinder wall, and eventual rupture.

This is a common condition in many Navistar engines, including all Powerstroke and the Ford installed 6.9L and 7.3L IDI engines but NOT in GM engines. If you have a Ford Diesel vehicle, DO use the additive. This condition ONLY effects the cylinder wall area, and is totally independent from corrosion and degradation of the rest of the system.

While Kent's remedy may be very useful in some cases, it is not necessary with a properly serviced and maintained system with Dexcool. Dexcool contains the necessary additives to prevent these conditions, if it remains unadulterated and serviced properly. This applies to GM Diesel engines, which is what we are talking about.

[rameye]

Gotcha..

thanks to all for the input, it is really appreciated.

[eracers999]

While Dmax Maverick is correct in what he has written, the GM diesels head gasket , raiator and heater core are suseptable to the effects of electrolisis. The tiny air bubbles that result from the violent combustion in a diesel will burrow holes in the cylinder walls of diesels that have a steel liner, ONLY when the a/f has become acidic. Electrolisis is not confined to this area. My problem is with this statement. Quote: The additive is not necessary in any GM Diesel engine, regardless of coolant. If you are only looking at the cylinder walls then you are correct. If you are talking any aluminum, or head gasket, or radiator, or heater core then you are mistaken. Green a/f is junk not long after new simply because it has nothing to counter acidicy. Mavericks maintenence of dex-cool is unique and i dont dought that he has great results. However, the dex-cool with the additive is a great combo because you can test it and it doesent have to be changed when maintained with the additive. On a seperate note i have often questioned the quality and consistency of dex-cool because of the way every thing else has been made, as cheap as possible. There is no way i would run 5yr 150 k on dex-cools claim. 1/2 that yes untreated you should be ok. Using the DCA you will be ok.
Kent