2019 Acadia thermostat replacement help

At zero...
More like a temp sensor.
If it had failed close= overheat.
If it failed open = P0128

P0128, means the computer has detected that the engine HAS NOT reached a preset engine temp in a certain amount of time on multiple occasions...
Meaning the thermostat is open and coolant is freely flowing at all times..
Especially on cokd engine starts, not warming up because its literally being cooled as soon as you start driving.

So since you dont mention a check engine light, Id think the sensor 1st.

The '19 thermostat is know to fail. $1300 is not out of line to replace it. The days of 2 bolts and a gasket are long gone.

divotdug said:

The '19 thermostat is know to fail. $1300 is not out of line to replace it. The days of 2 bolts and a gasket are long gone.

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Great, I have a '19! Warranty?
I kinda miss the 2 bolts, and a $6 thermostat including gasket.

Grantv said:

Great, I have a '19! Warranty?
I kinda miss the 2 bolts, and a $6 thermostat including gasket.

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I'm always scratching my head wondering about modern engine design. It's like who wakes up and decides to stick starters and thermostats under the intake manifold.

Exact same issue w/ my ‘18 SLT2 @ 82k. Had ‘Reduced Steering Assist‘, cooling fan on max speed, temp gauge at zero, + no AC also. P0128 showed up as ‘pending’ when scanned, thus unlit CEL. Had thermostat changed out for $1200, problem solved. You can clear code, or remove negative battery terminal, over and over till [email protected] freezes over, but problem will keep on reappearing till thermostat is replaced.

I did it myself in an afternoon. It wasn't hard. Make sure you replace the thermostat and the temp sensor.

F

jeromeh said:

I did it myself in an afternoon. It wasn't hard. Make sure you replace the thermostat and the temp sensor.

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Thanks, I'll come back to this if/when mine fails. $1300 US generally works out to around $2000 CAD, I'll take a day off work.

My 2017 SLT does it once a year. I just clear codes and move on. I really believe it is a computer glitch and not a sensor.

penster1 said:

My 2017 SLT does it once a year. I just clear codes and move on. I really believe it is a computer glitch and not a sensor.

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If the code pops up randomly ONCE, like you say and everything works perfectly in reality, then sure, it sounds like a glitch on your end.

Proper diagnoses of the problem needs to be done, honestly, like checking if it’s a sensor issue or a dash tachometer issue or the thermostat physically not working properly. 🤷🏻‍♂️

Bucko61 said:

Exact same issue w/ my ‘18 SLT2 @ 82k. Had ‘Reduced Steering Assist‘, cooling fan on max speed, temp gauge at zero, + no AC also. P0128 showed up as ‘pending’ when scanned, thus unlit CEL. Had thermostat changed out for $1200, problem solved. You can clear code, or remove negative battery terminal, over and over till [email protected] freezes over, but problem will keep on reappearing till thermostat is replaced.

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Have the exact same thing with my 18 SLT2 of 82000 plus miles on it and had it fixed today for $1326 Including the Coolant flush.

coachgio said:

My car has 68000 miles and I recently noticed temperature gauge pegged at zero. Checked online and I get multiple opinion’s including thermostat is bad. I called dealer and the quoted me $1300 to replace the thermostat. Yikes!!!! Anyone else having similar issue and or replaced their own?

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Yes just had it done to my 2018 GMC Acadia With 82000 miles on it and it was $1326 have to flush the radiator Too Included in the Price

Just had my 2019 SLT2 replaced today by my mechanic. Nobody had any inventory but the dealer so even with that it cost me $776 with flush. Was not happy with that until seeing the norm here is $1,300. So I am happy now, sort of.....

divotdug said:

The '19 thermostat is know to fail. $1300 is not out of line to replace it. The days of 2 bolts and a gasket are long gone.

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GM Cash Cow $$$$

DaHobbs said:

GM Cash Cow $$$$

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Not really. It's still just two bolts and a gasket. They just happen to be under the intake.

$1300 to replace a Thermostat (and coolant) sounds like they’re saying it’s $1100 in labor. At a dealership, that probably represents 8 hours of labor! A professional mechanic, with a professional lift, and all his professional tools right there at his professional fingertips … needs a full day in the shop to change a Thermostat?

Someone needs to do a time study here …

Colt Hero said:

$1300 to replace a Thermostat (and coolant) sounds like they’re saying it’s $1100 in labor. At a dealership, that probably represents 8 hours of labor! A professional mechanic, with a professional lift, and all his professional tools right there at his professional fingertips … needs a full day in the shop to change a Thermostat?

Someone needs to do a time study here …

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More like around 6 hours. Not very many shops still have a $135 an hour labor rate. In my neck of the woods it's not hard to find rates nearing $185.

Colt Hero said:

$1300 to replace a Thermostat (and coolant) sounds like they’re saying it’s $1100 in labor. At a dealership, that probably represents 8 hours of labor! A professional mechanic, with a professional lift, and all his professional tools right there at his professional fingertips … needs a full day in the shop to change a Thermostat?

Someone needs to do a time study here …

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You can get a AC Delco complete assembly with pipe for $50 on Amazon. It is a pain but do i yourself. Time consuming but not hard.

DaHobbs said:

GM Cash Cow $$$$

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Blame the engineers for this fiasco. The thermostat "assembly" runs from the front (left side) to the back of the engine. It is buried under the fuel rails. The proper procedure is to remove the intake. remove the fuel rails and fuel injectors just to get to the thermostat. And you will find that the thermostat is broken when you get there. Between plenum gaskets, injector seals, thermostat and a semi-required coolant flush $1300 is about right.

GMCbroke said:

You can get a AC Delco complete assembly with pipe for $50 on Amazon. It is a pain but do i yourself. Time consuming but not hard.

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Mind giving a link to where this assembly is available? I'm not finding it anywhere, including anywhere on Amazon.