Onan generator coolant

[jpapddp]

Any thoughts on using this coolant in my onon 7.5k generator? Seems like a better coolant but I am new to these things.

[vito.a]

You should be careful mixing coolants. Some coolants will form gel when mixed with incompatible coolants.
Good video in post #3.
https://www.irv2.com/forums/f258/ori...or-292407.html

I'd check the color of the coolant already in there and assuming it's standard ethylene glycol I'd stick with it.

[Bigd9]

I flushed out the coolant in the Onan and then filled it with the same coolant I use in the engine, which is Shell Rotella ELC Antifreeze/Coolant. Just makes it easier to remember when topping off the coolant.

[shootist]

The command is oat coolant. You can use it in the engine and in the gen set. The generator isn't a wet sleeve motor that I know of so don't put a silicate type wet sleeve antifreeze in it.

[Bigd9]

Just keep in mind that Freightliner does not recommend using anything but Low Silicate Ethylene Glycol based diesel coolant. Freightliner's sensors they installed in the coolant and dash heating systems systems do not like OAT coolants.

[jpapddp]

Great thank you for your help on this. I will be taking it back and stick to the simple stuff.

[shootist]

Originally Posted by Bigd9

Just keep in mind that Freightliner does not recommend using anything but Low Silicate Ethylene Glycol based diesel coolant. Freightliner's sensors they installed in the coolant and dash heating systems systems do not like OAT coolants.

Do you have a link to that statement about freightliner? I looked and can not find anything of the sort. Putting silicate in a dry sleeve engine wouldn't be good at all, referring to the onan.

[Bigd9]

Originally Posted by Bigd9

Just keep in mind that Freightliner does not recommend using anything but Low Silicate Ethylene Glycol based diesel coolant. Freightliner's sensors they installed in the coolant and dash heating systems systems do not like OAT coolants.

Originally Posted by shootist

Do you have a link to that statement about freightliner? I looked and can not find anything of the sort. Putting silicate in a dry sleeve engine wouldn't be good at all, referring to the Onan.

Unfortunately no. When I called them a few years ago that is what they told me. Then several others on this forum indicated more recently they were told the same thing when called. The reasoning always seems the same "our sensors do not like the ELC type of coolants".

I know the engine manufactures do recommend ELC coolants, but I suspect it is because a lot of owners never check or change the coolant for years and years, so ELC are designed to last longer.

BTW, my 2006 Cat engine and Freightliner recommend using only Low Silicate Ethylene Glycol based diesel coolant. My original statement was worded a bit confusing.

[shootist]

I believe it is the nitrate that causes problems. The prestone command is nitrate free as are many other oat coolants. I did find a thread on freightliners past problem. It has to do with copper and lead in the radiator and other metals in their sensors. It's a nitrate induced problem from what I can research.

[Tyee]

I called Cummins and they recommended there own Fleetguard ES Compleat OAT for maximum protection, especially with an aluminum radiator. It is nitrite free and also recommended for parent bore (no sleeves) engines. It's been in there 2 years, no sign of any sensor issues. Nice thing is it should outlast the motorhome.

[Jake21]

From the Onan manual:

5.7.3 Coolant Recommendations

Use the best quality ethylene glycol antifreeze available.

• Antifreeze should be fully formulated with rust inhibitors and coolant stabilizers.

• Mixed with fresh (distilled) water that is low in minerals and corrosive chemicals.

A 50/50 mixture is recommended for all climates and is suitable for temperatures down to –37 o C (–34 o F).