View Full Version : Oil cooling for engines possible??

05-05-2007, 11:41 AM
I was thinking about a beater mod this morning but I'm not sure if its possible.

Basically drain all the coolant out of the motor and replace it with either lightweight oil or auto tranny fluid.

Could this work?, or would it eat the rad hoses.

Seriously now, I need to know about silly **** like this.

05-05-2007, 02:38 PM
Im curious because in the event that an older engine starts seeping oil into the coolant and coolant into the oil this may be a decent idea to get a longer life from the beater car without investing in major repairs like a head gasket or replacment head for a cracked head.

Would the hoses burst I wonder though.

My 88 Doge Aries beater with a 2.5L is showing signs of a cracked head but runs fine and isn't worth a proper repair.

05-05-2007, 02:42 PM
From what I know about coolant fluid, all it does is raise the boiling temperature of water. Like for my dirt bike, for example, youre supposed to mix the coolant and water 50/50%. Instead of water boiling at 100 celcius, its not above that, and it is now more effective at cooling because its harder to make it come to a boil.

Just coolant does nothing, and just water boils too fast, but between them they make a good coolant.

I doubt oil raises the boiling temperature of water.

05-05-2007, 02:57 PM
My idea was to completely replace all the coolant with oil, literally filling the radiator with oil, boiling would definately not be a problem I just worry about the oil breaking down the rubber hoses.

In the event of a cracked head the oil will get into the coolant which doesnt bother me at all, its just the coolant getting into the engine and ruining the engine oil then in turn the main bearings, rings and getting coolant derposits on the plugs. If the cooling system is full of oil then these problems are taken care of except a little soot of the sparkplugs from burning off any oil in the combustion chambers if its getting in there at all.

What would be most suitable?, Tranny fluid, 5w30, baby oil(mineral oil)??

05-05-2007, 02:59 PM
Doesnt sound like a good idea. Coolant is made for one reason, and oil for another...

05-05-2007, 03:05 PM
Oil cooling works, its just not used in cars because its heavier and using oil for the coolant is more expensive then water and antifreeze.
Auto designers want the cheapest lightest options for auto's thats why you don't see any cars with them, it would be nice if they did though, you would never have any corrosion problems with your cooling system and your car would never boil over.

05-05-2007, 05:52 PM
so.... would the hoses burst?

05-05-2007, 06:00 PM
I think you'd be looking at the opposite problem. I doubt the water pump could pump the oil with enough pressure for a hose to burst.

Oil is made for lubrication, not for cooling.

05-05-2007, 06:23 PM
The cars only worth 150 bucks and I think it would make a good experiment.

05-05-2007, 06:26 PM
You're an r-tard.


05-05-2007, 06:27 PM
sound like a waste of time...

05-06-2007, 02:43 AM
I went ahead and tried it then tested it with a one hour hell rip.

Drained every last drop of coolant I could removed the thermostat, then poured in a gallon and a bit of cheap no name 10w30.

Started her up and went driving.
Idle is very hot but doesn't overheat, with highway driving or higher rpms the temp comes down probably due to the slower flow rate of the oil a higher rpm is needed to push the fluid at a proper rate.
Heater didn't work (no matter its springtime), air bubble trapped in heater core probably needs to work loose (dodge 2.2 and 2.5 were bad for this)

After shutdown the residual water in the system boils into the overflow and will eventually completely evaporate.

The crack in question that caused this is in top of the head allowing steam to escape into the area under the valve cover (PCV valve is removed and replaced with a filtered valve cover vent), now nothing but oil can seep into the engine or vice versa.

This is just a spare beater car of mine and if I can get to go for another 6 months I'll be happy, if it blows up I'll sell it for parts give an update.