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Discussion Starter #1 (Edited)
I've been reading up and watching videos on how to do a coolant change and in some of the videos, they talk about idling and waiting for the radiator fan(s) to cycle on. But I've noticed that my fan comes on right after starting the engine and stays on as long as I idle. I have no idea if/when it turns off when driving (is there a way to tell?). The engine is stone cold when this happens and the A/C is not on. The fan doesn't come on if I just turn the key forward without starting the engine. It comes on after starting the engine. The temp gauge is at the lowest point.

No codes. No overheating. Seems to drive fine. Temp gauge rises until it reaches just a hair passed half and stays there (which I read is normal and these gauges are not really showing actual temp all the time but should show overheating). Coolant looks fine in reservoir and radiator cap. But I'll see what comes out when I drain it.

Last year the water pump was replaced at the dealer after I noticed a noise and could see the fan moving off-balance.

Is the behavior I describe the normal operation of the fan? Or should the fan only be coming on when reaching certain temp?
 

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This fan is controlled by a viscous clutch, which means that is will always spin because the viscous material always causes some friction. It is normal for the fan to rotate when the engine is running, as the temperature of the coolant increases beyond around 220 - 230 degrees, the PCM will signal the fan clutch to increase the fan's speed.
 

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Discussion Starter #3
This fan is controlled by a viscous clutch, which means that is will always spin because the viscous material always causes some friction. It is normal for the fan to rotate when the engine is running, as the temperature of the coolant increases beyond around 220 - 230 degrees, the PCM will signal the fan clutch to increase the fan's speed.
Thanks! So during the point of the flush where the online instructions say to wait for the fan to come on, I'll be listening for the fan to spin faster?
 

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Yes, but I don't know what that is supposed to do with doing a flush. All that needs to happen is for the thermostat to open and allow coolant to circulate.
 

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I'll have to go back and watch the videos but I think it had something to do with the burping after filling.
 

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In order to "burp" the cooling system (remove air), the thermostat must be open. That means that the engine needs to be at operating temperature.
 

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Discussion Starter #7
In order to "burp" the cooling system (remove air), the thermostat must be open. That means that the engine needs to be at operating temperature.
I just did the coolant change. As far as I'm aware, the cooling system was never touched until last year when the pump was replaced. It wasn't my car at the time and I don't have an invoice of what all was done so I called the place. They couldn't help. Said the only info they can see about the visit was the notes that the pump was replaced. I asked if new coolant is put in when they do the replacement and they said yes, but only what they lose which might be about a gallon. Is that really all they'd lose? So hearing that and knowing the rest of the coolant is probably 14 years old, I decided to do change. I think it went ok but it's the first one I've done so I don't know,

I pulled the caps and bottom hose and drained it. The fluid that came out looked perfect. As did what was in the reservoir (which I removed with a pump). No sludge, no crud, no cloudiness- nothing. 2 gallons of kool-aid with a handful of tiny black specks at the very bottom. That was all. I was pretty amazed. I'm wondering if maybe they changed most of the fluid with the pump. But even if they did, I'm glad to see everything so clean a year later.

I put the hose back on. I used one of those no spill funnels and started pouring in the new coolant (I went with Prestone 50/50 Dex) until it was up into the funnel. Then I massaged hoses, bumped the vehicle a bit, tapped some areas and air bubbles were coming out. Then topped some more off as it went down. Once it seemed I got out all the bubbles I could with the car off, I started it up. More bubbles started coming out. I did some more messing with the hoses and bumping the vehicle and air kept coming out. Then I turned on the heater for a while. Then I ran it at 2k for a bout 30 seconds or so a couple times. At one point, the fan started blowing faster/louder. I'm not sure how long it was up to temp, but the gauge was showing 210 and stayed there when I looked at it.

It wasn't burping anymore air on its own, but when I'd knock the vehicle around a bit while it was running, big bubbles would come out. It did this every time. I started to think I was introducing that air somewhere like having it come from the reservoir hose or something. Because messing with the hoses, idling or running at 2k produced no more air and I wasn't sure how long I should be idling it so I stopped at that point.

I drove it, everything seemed fine. No lights, gauge stayed smack in the middle, no sounds, etc. What I took out filled back up the 2 gallon jugs I used. I think there is slightly more in the ones I filled back up and I spilled a little draining it, but the reservoir is also a little lower than it was before I drained so I'm real close to exactly what I took out. My reservoir was a quarter inch below the full line before I started. Now it's maybe 3/8. Instead of opening up the 3rd gallon just to top it off, I'm going to put back in a little of what I took out since it looked so good. I'm leaving the jug sit overnight to settle and then will pour some off the top in the morning.

If you've read this far, thank you! And I have a question. Is there another round of burping I should do now after driving it a bit? Will it burp itself any while I drive (into the reservoir)? Or does that only happen with the cap off?
 
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