2017 Chevy Impala 3.6 coolant change/flush

[irv]

My wife's car, 2017 Impala 3.6, is due for a coolant change as it is over the 5yr mark and is getting somewhat discolored/weak.
Is there much to this, much to be cautious about or is it pretty much straight forward? I believe there is a drain petcock on the lower portion of the rad on the passenger side?
When refilling, as there is no rad cap, is all new coolant just added through the pressure bottle/tank? The manual reads 9.4L's or almost 10 qrts. of fluid. I plan on mixing it 50/50 (Dex-cool concentrate) but was thinking 60/40 (coolant to water) because of living in southern Ontario. Thoughts?

Also, is just draining out the old then refilling new good enough or should it be flushed? If flushed is the answer, is that just adding it full of water, running it for a few minutes or so then draining that out or is it something completely different than that? I've never done this on these types of cars before, only older ones where you remove the lower rad hose and then fill through the rad cap. Very little info on youtube that I could find specifically for this car.

Thanks in advance.

 

[Slick3914]

A drain & fill will be just fine.

 

[irv]

A drain & fill will be just fine.

Like I asked above, it is straight forward? Drain and just refill in the overflow/pressure bottle/tank or is there more to it if you know?
Thanks.

 

[Plawan]

If it has a radiator cap on the radiator it’s a simple traditional type coolant system. You can just drain and fill the radiator. Let it bleed the air out until it remains full. Drain the reservoir tank and fill to full line.
Keep an eye on the level in radiator for a couple weeks.


If it doesn’t have a radiator cap its probably a closed system and will have a separate burp valve somewhere.
If that’s the case you just drain the radiator through the petcock and close it. Find the the burp valve and open it while filling iup through the reservoir tank. Leave the burp valve open until coolant comes out. close burp valve. Continue letting air bubbl out through the reservoir tank. and keep topping off till the level stays full. Take a 20 min drive and check level. Keep an eye on the level for a couple weeks and top off as needed.

 

[irv]

If it has a radiator cap on the radiator it’s a simple traditional type coolant system. You can just drain and fill the radiator. Let it bleed the air out until it remains full. Drain the reservoir tank and fill to full line.
Keep an eye on the level in radiator for a couple weeks.


If it doesn’t have a radiator cap its probably a closed system and will have a separate burp valve somewhere.
If that’s the case you just drain the radiator through the petcock and close it. Find the the burp valve and open it while filling iup through the reservoir tank. Leave the burp valve open until coolant comes out. close burp valve. Continue letting air bubbl out through the reservoir tank. and keep topping off till the level stays full. Take a 20 min drive and check level. Keep an eye on the level for a couple weeks and top off as needed.

Sorry for the late reply.

No rad cap, just surge/reservoir tank. I haven't gotten around to it yet but had a look at things the other day while draining out the trans fluid. Lots to remove to access the petcock, (which makes me nervous to utilize due to breakage stories), but the lower rad hose, imo, even if I remove everything, is still going to be real tough to access due to cooler lines and the like in the way.
I did find a burp valve, or likely better described as a vent, that I found on the upper rad passenger side. Glad to see it. Curious, how many people have had issues breaking the petcock while trying to loosen it? It was a friend of mine who use to work at/run a rad shop that told me to try the lower rad hose instead so I tend to believe him. I likely should have taken it to him initially but I've already purchased 2 jugs of dex-cool and was hoping to do it myself.

 

[Plawan]

Sorry for the late reply.

No rad cap, just surge/reservoir tank. I haven't gotten around to it yet but had a look at things the other day while draining out the trans fluid. Lots to remove to access the petcock, (which makes me nervous to utilize due to breakage stories), but the lower rad hose, imo, even if I remove everything, is still going to be real tough to access due to cooler lines and the like in the way.
I did find a burp valve, or likely better described as a vent, that I found on the upper rad passenger side. Glad to see it. Curious, how many people have had issues breaking the petcock while trying to loosen it? It was a friend of mine who use to work at/run a rad shop that told me to try the lower rad hose instead so I tend to believe him. I likely should have taken it to him initially but I've already purchased 2 jugs of dex-cool and was hoping to do it myself.

Yep the lower radiator hose will work fine too.
I dunno why they gotta go and make a simple maintenance/repairs hard these days by putting things in the way.
On my old fusion, ya have to remove the intake to change the Pcv valve.
Gotta remove the upper intake to change spark plugs on my 2019 grand caravan . No dipstick on the transmission on the grand caravan and no dipstick or even a dipstick tube on my 2020 Ram.
It’s really not necessary even with all the stuff they pack under the hood theses days. They’re making it so most people won’t or can’t preform simple maintenance or repairs now. Making other wise affordable & simple repairs expensive and time consuming.

 

[KrisZ]

I never had an issue with the radiator petcock. But you need to use the widest flat screwdriver head or the biggest cross head. It’s easy to mangle up the plastic screw head with a small screwdriver head.

If you never did it before, makes sure you have full visibility of what you’re doing. Press the screwdriver in pretty hard while turning to avoid slipping it and damaging the petcock.

 

[irv]

I never had an issue with the radiator petcock. But you need to use the widest flat screwdriver head or the biggest cross head. It’s easy to mangle up the plastic screw head with a small screwdriver head.

If you never did it before, makes sure you have full visibility of what you’re doing. Press the screwdriver in pretty hard while turning to avoid slipping it and damaging the petcock.

The vent looks like it will need/take a screwdriver but the petcock looks like this. Twist/turn to loosen and tighten. Some reading I've done said a pair of pliers may be required to loosen it. Read this is where, if one doesn't go gingerly, that things can head south on you if you're not careful.

https://www.amazon.ca/Dorman-61123-HELP-Radiator-Drain/dp/B000C5E7JI?ref_=Oct_d_orecs_d_9163384011_2&pd_rd_w=U2YtT&content-id=amzn1.sym.e9443a82-1e85-46ac-a327-f05a3d24bc0e&pf_rd_p=e9443a82-1e85-46ac-a327-f05a3d24bc0e&pf_rd_r=6SNW4TGNSC09GFKP6K93&pd_rd_wg=HV3ry&pd_rd_r=c8f6adb1-730a-4bdd-ab15-3a4246ee5aac&pd_rd_i=B000C5E7JI

 

[irv]

Finally got around to doing it a few days ago. Simply removed three 7mm bolts on the underbody cover, reached up and turned the spigot a bit, attached a small hose then opened the spigot the rest of the way. I drained out about 5 ltr's/quarts then applied a bit of air to the surge tank (but was hesitant to apply to much) but did manage to get a bit more out. Buttoned everything up. Added enough Dex-Cool to fill surge tank, started car, squeezed upper rad hose, turned heat on high and re-filled as the surge tank went down. All went well. Surge tank is staying full after a few drives. Total amount on a completely empty engine/rad/hose is around 9 ltr's they say so I guess I only got about half out. I did not do a flush. I will the next time, maybe this fall/next spring add more air.