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· Registered
1 Posts
Discussion Starter · #1 · (Edited)
Flushed the coolant in 2021. I suspect there was air I didn't get out. I haven't opened the rad cap until today and it wasn't like this even before I flushed it... Not sure if it's the radiator or heater core. The next day after I flushed it, when I went to drive it, I heard a sloshing noise. So I popped the rad cap open and let it go for a little while. Can't remember if I was running the heat or not. The sloshing noise went away after.

I could have sworn I got all the air out, so I'm kind of confused. I did use water and a chemical cleaner before draining and filling with coolant, so maybe I didn't get all the plain water out?

Any feedback would be appreciated.


· Super Moderator
2004 TL Magna(aka Diamante) AWD, 6g75 engine, F5A51 automatic trans.
484 Posts
I am not sure why the rust is there.

Possibly it is an incorrect mix of coolant, or poor quality.

Is the water where you live "hard"?

i.e. Does it contain a high % of minerals?

Some manufacturers/mechanics specify only distilled water to be used in radiators, but I believe that is going too far & too expensive.

From an Australian source:

The best/easiest way to get rid of air in the system is to put a car jack underneath the front.

Or park the car on a slope with the front pointing up the hill.

The air will eventually rise to the highest point, which will be the radiator cap hole.

Fill the cooling system slowly with the engine running, and the excess air will gradually escape through the hole.

Alternatively, use the "bleeder" nipple, which should be in/near the thermostat housing.

You might also want to check your overflow bottle, and clean it out before refilling the system.

· Registered
2001 Eclipse Spyder GT. V-6 [6G72].
86 Posts
If there is rust, there is [or has been] air in the system. Simple chemistry. Oxygen mixing with steel. The oxygen, oxidizes the steel, and forms rust. Coolant has a rust inhibitor in it, but you still have to keep the air out. ...J.D.
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