PDA

View Full Version : It: re anti freeze



wtrueman
03-06-2016, 01:00 PM
Hi all. Ot because I have about 1/2 gallon each of regular auto anti freeze and about 1/2 gallon of diesel anti freeze and have been told NOT to put or use the diesel af in my gas driven truck. And not to mix them for use. Why? Thanks for your time, Wayne.

steve45
03-06-2016, 02:10 PM
I don't know about auto and diesel, but you sure don't want to mix the old green stuff with the newer orange stuff. It will gel up and plug your radiator.

kendall
03-06-2016, 02:28 PM
diesel antifreeze contains anti cavitation additives that aren't required in gasoline engines. Generally nitrate based, not sure if it's harmfull to gas engines, but it is required for diesel, available as an additive for regular antifreeze when used in diesels.

Black_Moons
03-06-2016, 10:16 PM
diesel antifreeze contains anti cavitation additives that aren't required in gasoline engines. Generally nitrate based, not sure if it's harmfull to gas engines, but it is required for diesel, available as an additive for regular antifreeze when used in diesels.

Why do diesel engines need anti-cavitation additives? Whats so special about a diesels coolant system?

Doozer
03-06-2016, 10:27 PM
I am only guessing,
but maybe vibration?

-D

Iraiam
03-06-2016, 10:56 PM
Why do diesel engines need anti-cavitation additives? Whats so special about a diesels coolant system?

I'm betting it's because many diesel engines have wet sleeves, the coolant has direct contact with the O.D of the cylinder sleeves. The coolant has additives to keep it from bubbling, and bubbling would cause the coolant pump to cavitate.

Willy
03-06-2016, 11:15 PM
I'm betting it's because many diesel engines have wet sleeves, the coolant has direct contact with the O.D of the cylinder sleeves. The coolant has additives to keep it from bubbling, and bubbling would cause the coolant pump to cavitate.

This is partly correct. The cavitation erosion is the result of vibration as Doozer already mentioned. The vibration transferred to the cylinder liner results in the liners surface first moving rapidly toward the coolant and then very rapidly away from it. This results in coolant vapor bubbles that collapse or implode on the liner's surface. This in a nutshell is cavitation erosion and how it affects diesel engines. Tiny destructive implosions that take tiny bits of metal at each implosion.

Having seen how fast this can destroy a diesel engine running on just straight water I can attest to the fact it is a very real issue. I'm talking less than a thousand hours in a high hp diesel engine that is working hard, resulting in liners that looked like they had been exposed to a strong acid.

Iraiam
03-06-2016, 11:42 PM
Ah, very good. Cavitation erosion, I saw the term cavitation and assumed it was referencing the coolant pump.

Yow Ling
03-06-2016, 11:53 PM
While we are talking antifreeze, there are glycol based and waterbased, any big advantage to either one.
We arent allowed glycol in racebikes as its a bit slipery if spilled onto the track

Iraiam
03-07-2016, 12:08 AM
While we are talking antifreeze, there are glycol based and waterbased, any big advantage to either one.
We arent allowed glycol in racebikes as its a bit slipery if spilled onto the track


I had the same restriction. Water coolants transfer heat very well but have corrosion issues, glycol coolants don't have the corrosion issues, but don"t transfer heat as well. I used to change my water based coolant regularly, I had read that the anti-corrosion additives necessary in the water coolants were consumable (they would go away somehow?).

ironmonger
03-07-2016, 12:41 AM
The 'glycol' based antifreeze you put in an engine is not pure ethylene glycol. It is treated with anti corrosion chemicals and buffering agents to keep from destroying your engine. This is particularity necessary with aluminium block engines.

A good old boy on a job site had 'procured' a few gallons of anti freeze to save money on his car. Bad idea... aluminium corrosion in an engine is not pretty. When the glycol is installed in a chilled water piping system, it is monitored for solution chemistry and treatment chemicals are added to keep the 'water' from damaging the piping. The propylene glycol, the RV non toxic antifreeze additive, is particularly aggressive towards aluminium.

Ed ke6bnl
03-07-2016, 08:48 AM
so what antifreeze is recommended for a diesel. I have a Dodge diesel and have been using the regular green stuff am I in need of a replacement.

ironmonger
03-07-2016, 09:02 AM
so what antifreeze is recommended for a diesel. I have a Dodge diesel and have been using the regular green stuff am I in need of a replacement.

Iím not trying to be snarky, but I would use whatever the manufacturer recommended.

There is no sense experimenting with a couple of thousand dollars of engine over someoneís idea of what is correct or not.

Willy
03-07-2016, 10:26 AM
Iím not trying to be snarky, but I would use whatever the manufacturer recommended.

There is no sense experimenting with a couple of thousand dollars of engine over someoneís idea of what is correct or not.


I very much agree with what Paul stated above.
Engine coolant formulations and the recommendations issued by the OEMs have become very complicated over the last 20-25 years. One cannot simply introduce any old thing into the cooling system without running the risk of doing some very expensive damage. It's not just the radiator you will risk doing damage to but everything the coolant touches, which pretty well means the entire engine.

Due to the ever increasing complexity of technology and metallurgy inherent to modern engine designs it is imperative that you at least find out what the specs are for the vehicle that you intend to replace coolant in. The chemical cocktails are so diverse for coolants that simply adding whatever is on sale at the local big box store won't cut it unless you have verified that it meets the OEM specs for your vehicle.

Seriously, do your homework. You don't have to buy the coolant from the dealership, just match up the specs.
You can do more damage to your engine in 2-3 years by running the wrong coolant than you would by using cheap engine oil. Unfortunately just like any other automotive fluid, it always "fits".

Just as an example below is a page from Ford on their various coolant specs and the warnings about using these products "only when specified". Trust me they aren't joking, other OEMs will have similar warnings.

https://www.fordparts.com/Products/Chemicals-EngineProducts-Coolants.aspx

TWiersma
03-07-2016, 10:33 AM
Low silicate antifreeze is what is called for in most older wet sleeve engines. As a side note if you have a diesel you should also be checking the DCA level with test strips and adjusting with additives. If you have a newer engine with you should check the recommendations and talk to a good supplier not the guy at the big box store.