Diesel coolant additive

[Vaman]

Talking with the Cummins rep he swears every ISB should be using DCA in the coolant even though we're sleeveless. He says it's based on the heat level in our engines. My Dodge manual says doesn't mention it and I believe it actually says do not use an additive. The rep says Dodge, as usual, is wrong. How many of you use a DCA or buy coolant with DCA in it?

 

[Cooker]

The additives I thought were to extended the life of the coolant. The John Deere antifreeze mentioned nothing about an additive other then to add it if the coolant test out not up to spec. This was recommended at annual intervals.

 

[illflem]

I add DCA (Nalcool) yearly and never change the anti-freeze. Both my '95s have the stock AF as most of my seven tractors, one John Deere has had the same AF at least 12 years. Used to test but found once a year works just fine, this is not rocket science. This is the system most OTR trucks use to avoid AT changes. If you have just one engine to deal with change the AF, as I understand it all extended life AFs are now approved for Cummins.

 

[Dave Fritz]

I use Cummins Fleet Charge antifreeze (which has already DCA it) in my tractors and diesel trucks. The Ford gas truck gets regular antifreeze. FWIW: I change all coolant every two years.



Dave

 

[RustyJC]

Originally posted by Vaman

Talking with the Cummins rep he swears every ISB should be using DCA in the coolant even though we're sleeveless. He says it's based on the heat level in our engines. My Dodge manual says doesn't mention it and I believe it actually says do not use an additive. The rep says Dodge, as usual, is wrong. How many of you use a DCA or buy coolant with DCA in it?

Well, I just bought some coolant from Cummins Southern Plains last week. The parts manager (seemed to be a knowledgable "old hand") asked what vehicle I was buying it for. When I told him an ISB in a Dodge, he was very emphatic in saying that the Dodge version of the ISB is designed to run on low-silicate ethylene glycol coolant, and that no ISB engines (even the ones that run on propylene glycol) need DCA since they are sleeveless engines - the cavitation inhibitor in DCA is essential for wet-sleeve engines. Cummins Southern Plains even stocks low-silicate ethylene glycol just for the Dodge ISB applications (branded as Pyroil, a division of Valvoline).



Just my recent experience... .



Rusty

 

[Vaman]

The more I see the more I think that the silicate level is the big issue here. Apparently at high temps, the silicate tends to precipitate out. The DCA is supposed to contain something that bonds to the metal and protects it at the high temps.

 

[Archive]

The only press release I've personally seen from Cummins about extended life coolant is for approval of Equilon (Texaco) brand only. I don't know how similar the other brands would be to Equilon's formulation.

 

[The patriot]

I changes my AF once, and it's just about due now. I called the local big truck dealer (Mack in Trenton) and they delivered Quaker State AF, (low silicate).

I didnt go to them for any paticular reason other than they'll deliver to my house, being I dealt with them when I had my own trucking bidness.

I have DCA in the garage that I never added, it's made by Fleetguard DCA 4 (DCA 60-L). I got this about two years ago, but I think the salesman told me to NOT use more than a half a bottle in one change.

I now have Rotella pre mixed AF waiting for me to use. It was $25. 00 a case at the local BJ's.

Eric

 

[HEYBOSS]

Originally posted by Vaman

Talking with the Cummins rep he swears every ISB should be using DCA in the coolant even though we're sleeveless. He says it's based on the heat level in our engines. My Dodge manual says doesn't mention it and I believe it actually says do not use an additive. The rep says Dodge, as usual, is wrong. How many of you use a DCA or buy coolant with DCA in it?

Here's right out of the horse's mouth

 

[DPelletier]

I am more confused than ever. The Pwrstrk is also sleeveless, yet it definitely needs the additives. So when Cummins says "since the engine in the Dodge Diesel has no liners, it does not require and additive" like thier saying " 2+1=3", it doesn't make sense that some linerless engines need them and some do not.

If our engines truly do not require an additive, it is not because they don't have liners

So the question remains



Dave

 

[RustyJC]

Pardon the Long Post!

Originally posted by DPelletier

I am more confused than ever. The Pwrstrk is also sleeveless, yet it definitely needs the additives... If our engines truly do not require an additive, it is not because they don't have liners

So the question remains...

Dave,



You're exactly right. What determines the need for DCA is the question, "Is this engine design subject to cavitation?"



Cavitation is damage to the water jacket side of a cylinder surface caused by a vibration phenomenon known as "bell ringing". Wet liner engines are most prone to cavitation since their liners are normally supported by block fits at the top and bottom of the liner. So, what happens to produce cavitation? When that particular cylinder fires, the piston will move through its clearance with the liner, and the thrust face of the piston will (for want of a better term) "slap" the cylinder wall. This produces the same effect as striking a bell with a hammer - the liner vibrates or "rings". On the coolant side, as the vibration of the liner moves the liner surface away from the coolant, the area at the liner/coolant surface will drop below the vapor pressure of the coolant, and a gas bubble will form. When the liner moves back into this void, the pressure increases, the bubble implodes, and a high velocity "jet" of coolant strikes the cylinder wall. This will tend to blast away a few molecules of the liner surface, just like a high pressure washer. Over time, pits will form which can progress all the way through the liner - then coolant will leak into the combustion area, and things go downhill fast! Depending on the stiffness of the cylinder walls in the block casting, some linerless engines (i. e. , the PowerStroke) may be subject to this same "bell-ringing" phenomenon and resultant cavitation damage.



DCA protects against cavitation with an additive called "cavitation inhibitor". In effect, cavitation inhibitor plates out on the surfaces (including the wet liners or cylinders) in the cooling system. This plating is sacrificial in that the plating instead of the liner/cylinder surface is blasted away when the coolant bubbles implode. Of course, after the coolant is in contact with the liner/cylinder again, more cavitation inhibitor will replate the liner/cylinder surface. This sacrificial action is why the cavitation inhibitor package in DCA can be depleted, and is why DCA must be tested and "doped" if the additives fall too low.



So, to our ISB's. Apparently Cummins' service experience is that the cylinder walls of the ISB are sufficiently rigid (unlike the PowerStroke) that they are not prone to "bell-ringing" and resultant cavitation damage. Therefore, DCA is not required in our engines.



Rusty

 

[DPelletier]

Rusty,



Thanks for the extremely detailed explanation. This, I can believe!

In simple terms, our motors don't need the additives because experience has shown that our engines are not prone to this kind of damage, unlike the pwrstroke. The likely reason for this being increased rigidity of the cylinders. Not sure why Cummins couldn't have said that instead of, no liners = no problem. All right! I buy it!

Dave

 

[HEYBOSS]

Originally posted by DPelletier

I am more confused than ever. The Pwrstrk is also sleeveless, yet it definitely needs the additives. So when Cummins says "since the engine in the Dodge Diesel has no liners, it does not require and additive" like thier saying " 2+1=3", it doesn't make sense that some linerless engines need them and some do not.

If our engines truly do not require an additive, it is not because they don't have liners

So the question remains



Dave

OK. I will try to explain what I've learned from my machine shop guy.



Wet liners like used on bigger diesels=bad cavitation

Powerstrokers don't have wet liners and their cylinders are part of the block like a gas engine, therefore there's nothing between cylinder wall and block, so cavitation will eat through bock cylinder wall. Our Cummins have liners that are pressed into block, so cavitation would have to eat away through block and then through the press fit liner. call it double wall. I guess due to our engines having a press fit liner into a cylinder block are less prone to cavitation because there's a lot less vibration from pistons.



Did I confuse anyone? Hope it cleared up some