2013 GMC Acadia Transmission Hot Idle Engine transmission overheat

Today I had a 2013 GMC Acadia in the shop with some transmission problems and I never thought this would be the issue even actually fix the problem. The customer said the "Transmission Hot Idle Engine" message came on after driving an hour on the highway. They pulled over and let the engine idle for 15 mins and the light went out but came back on after some more driving. They took it to a big box quick lube store and the service writer recommended a transmission flush because the fluid was dirty. They decided to come to our shop instead and I checked it out.
First thing I did was check the fluid level and then drove it around the block and noticed a slight shift flare from 2-3 and 3-4. pulled it back into the shop scan it with my Snapon Modis Scanner and found to codes in transmission or engine modules. I then went to data and logged the transmission information while driving on the highway about 15 miles. I noticed that the transmission fluid temp reached a temperature of 240 F and the engine coolant only reached ~205 F. The transmission cooler is built into the coolant radiator so the coolant has to cool the transmission fluid.
I was pretty sure the transmission was failing but wanted to make sure so I then checked the fluid again and notice some aeration of the fluid. I was think that the filter may be plugged causing the issue but decided to search the web and found a blog post about fluid level being too high causing the issue. I then checked the fluid again and noticed the fluid was actually over the full mark. This dipstick is very hard to read and even with dirty fluid I couldn't see that the fluid was several inches overfull. I found that if you use a paper towel and lay the dipstick down flat on the paper you can see how high the fluid level actually is.
So now we need to drain some fluid off and test it again. Since the customer wanted a flush I went ahead and performed the service and then used the drain on the machine to let the transmission line pressure push the fluid out. I drain a total of 4 quarts out of this transmission to get it at the proper level. It was probably 3.5 qts over but I has put about .5 qts of cleaner and conditioner in the fluid.
Now that the fluid was clean and at the correct level I drove the vehicle on the same route and at the same speed and the transmission fluid stayed at 200 F. WOW a 40 degree difference on a 20 minute test drive.
I think the fluid aeration was causing cooling inefficiency and the shift flares witch also builds more heat.
If you found this information helpful then please like the video and/or share it to you favorite GMC acadia forum.
This information also applies to any vehicle. Saturn Aura, Pontiac G6, GMC Acadia, Buick Enclave and LaCrosse, Cadillac SRX and the Chevrolet Equinox, Malibu, Traverse and Impala. and any vehicle with the 6T75 transmission are highly affected by the overfilled fluid.
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[@jaywebb3105]

2007 acadia owner I got the same message but after climbing up a mountain. I pulled over and let it idle and after a while I was able to continue. I just watched this and then went out and checked my level with the paper towel and sure enough it was over full. Two weeks ago the gear selection cable pulled out but I was able to just pull the clip and reinstall. I'm thinking the extra heat caused it to pop out. Great video the paper towel trick was spot on.

[@ThePracticalMechanic]

I wish those dipsticks were easier to see when over full. I have had several since this video that were at least a qt over filled.

[@stevebrackett2676]

This is an excellent video & explanation of how/why the trans had an issue. Thank your for the effort to make it.

[@ThePracticalMechanic]

Thank you!!! And your very welcome.👍🏻

[@justmy2cents_]

I had this issue in my 2004 GMC Envoy some years back it ended up being my transmission cooler lines needed replacing!! Love my Envoy it's hard to beat!!

[@lesliejonesjackson7051]

Thank you so much for this video! Same thing is happing with my Acadia. I’ll be taking mine in tomorrow.

[@lts7565]

Excellent video and explanation. Thank you.

[@namjanamja747]

as my cars transmission get hot the engine stalls... what do you think it is causing that problem?

[@MarkSmith-js2pu]

I just changed my 2012 Acadia Trans fluid yesterday and I think I got a little too much in there. It’s hard to tell on the dipstick. It shifts better, it wasn’t bad in the first place. I’m wondering if a little too much is bad.

[@ThePracticalMechanic]

how much is too much? 1/4"? 1"? I think a quart over full would probably be ok. im guessing a quart would raise the dipstick 1/2" or so.

[@alikareem1997]

Hello, I also have a problem with the high temperature of the tcm gearbox, and also the gearbox oil, which reaches 273 F. Is the reason for this being the high oil level or another reason, please answer code is P0989 obd2

[@destinyd1308]

i was reading that 175-210 was a recommended trans temp i imagine it being to full was probably not a good start i wonder if the client added more

[@jobanirubio5683]

Hi I have this same car, My question is, can I replace my Transmission Filter thru the side transmission pan?

[@LiRicard-up2ww]

Question… I have a 2017 gmc Acadia V6 slt The transmission FLUID, temp reaches 217-219 from sitting in traffic too often… The knob between the C and H, never moves even though my transmission fluid temp increases… What should I do? I’ve taken it in for a gasket leak and it was fixed. The coolant is fine The transmission fluid temp still gets too high no mechanic can tell me what’s wrong with it I smell burning all the time while driving and a clearing gas comes from the car, not too much but you can see it

[@ThePracticalMechanic]

Since this transmission is cooled by engine coolant you may see 220* temps when sitting in traffic or in a drive-thru. I would check to see if any engine oil is leaking onto the exhaust causing the hot smell.

[@alkarim5890]

Did you figure it out ?

[@abelardoduarte4082]

Great video, thanks for sharing, a few questions, how do you proper check the fluid level on the stick? Should the level be between the XXX marks? When it's at normal hot tempreatures, should the fluid cover the Hot mark (covering all the three letters) ? I see on your video that you move your finger on the stick but I'm not sure where should be the right level. Thanks in advance.

[@ThePracticalMechanic]

Your best range would be in the cross hatches. If the fluid is up past the HOT letters and you go up a long hill or drive with the car loaded the fluid level may rise even higher as the fluid will get hotter when heavy loads are applied. Mine was over an inch up the dipstick cable and that is what caused the issue. Just into the HOT letters when checking it on a hot car might work just fine for most driving.

[@Roniesantosbr]

Thanks a lot for the video!

[@ironfistarrival]

Dear friend hi again what are for example Electrical or sensor issues that could cause transmission to slip or stall once in a while beside Mechanical or ove fill issues ? Thank you .

[@terrytabosa2513]

Great video, thank you so much

[@hamedali3232]

That good bro, I had same issue in my vehicle Acadia 2012. In highway with RPM 3000. Show transmissions hot edile, I will Change fluid and check it ,

[@ThePracticalMechanic]

How did you make out? Temps lower after fluid change or level correction?

[@Davidh741]

Love the video can i ask separate question i have gnc Acadia 2013 head wheel bearing replaced apparently they broke the abs sensor but replaced with after market but did not work there was grading noise when break was applied and abs was on with all wheel drive off and stabilitrak off. Head to drive car like this to get to work but next day they replaced everything abd sensor with original part and all works fine but i can still hear slight low level grind or skip like when i apply break all the way down in low speed it does not happen all the time but it does happen any ideas much appreciated

[@ThePracticalMechanic]

If the abs is still having “false activations” then the bearing that was installed might be faulty. If the vehicle has a lot of rust then the rust may be interfering with proper installation of the bearing and/or speed sensor. It would probably be best to take a mechanic from the shop on a test drive and show them what’s happening.

[@TheMochaangel]

I'm here because my 2011 buick enclave cxl just alert the "transmission hot, idle engine " signal.... so is the resolution simply to check the levels and get a transmission flush??

[@gregorytamanimusictv8834]

Very informative nice video

[@10secondsofnature31]

Had that message today and I think I think it had to do with my gas tank running on fumes..idk I never had that message before and today I didn’t noticed my gas gauge was on low so I think the trans was working twice as hard but again idk ...

[@fernandovazquez5296]

WHATS THE NAME OF TRANSMISSION CLEANER

[@lesliejonesjackson7051]

BG Transmission Cleaner

[@leorodz1268]

I have a 2010 buick lacrosse what else can cause this problem?

[@chrisbranch231]

Bout to let some fluid out of mine tomorrow

[@ShaunCruzNYC]

Is there a follow up to this solution? Does it truly work?

[@ThePracticalMechanic]

Shaun Cruz The owner of the vehicle hasn’t had an issue with it since I serviced the transmission and corrected the fluid level. The biggest issue was the fluid level. If you have one that is having issues the double check that you fluid isn’t overfilled. If your fluid level is correct and you are having overheating or shifting issues then this probably won’t help you. I believe there is a “wave plate “ problem internal of the transmission that require more intensive repairs to fix. Hope this help.

[@ironfistarrival]

Hi , so any overfill of the Transmission could cause Slipping of the transmission of any car model ?

[@ThePracticalMechanic]

It depends. Some vehicles like trucks and larger SUV’s have deeper transmission oil pans that are less susceptible to fluid aeration. Many smaller vehicles will have issues with a slightly over filled transmission.

[@ironfistarrival]

@@ThePracticalMechanic ..What about Hummer H3 Transmission overfill of Transmission ? Could it cause the Shifting gear to have problem to shift gears sometimes and slipping ? Thanks .

[@ThePracticalMechanic]

@@ironfistarrival it possible but I do see lots of bad transmission in those vehicles. Are you running an aftermarket air filter setup? There is a sensor that measures the air entering the engine(MAF sensor) and if it get dirty or oily then the reading will be off and the transmission may not shift properly.

[@ironfistarrival]

@@ThePracticalMechanic ..Hi there , thank you for your help , the MAF is New , i think it is either the too much oil in there [ the Fluid was changed with its filter ] , or some transmission sensors or other electrical parts of it , or transmission getting old ? or any other mechanical parts connected via transmission ? Hard to tell for me for now ..

[@davidmartinez6759]

I got the GMC Acadia with the same problem

[@johnnyjesus8]

Ive got the same car same year and it's a peice of crap if I drive around 70 80 miles an hour that stupid warning comes on pull over and idle engine it's a pain. I pull over for about 5 minutes till the light goes off it happens every 8 to 12 miles. I'll never have another one of these cars again.

[@herockhernandez2794]

What kind of scanner is that

[@ThePracticalMechanic]

Herock Hernandez scan data was captured with a snapon modis edge and the reviewed on my computer using shopstream connect from snapon.

[@davidmartinez6759]

Hey my friend where are you located?

[@ThePracticalMechanic]

Southern Colorado

[@ishish9283]

2014 Chevy Traverse transmission problems 2013 GMC Acadia transmission problems Chevy cars and trucks transmission problems I love the old-school Chevys always new school Chevys trash how do you fix a transmission problem from a Chevy these days buy a Toyota or Kia.

[@ThePracticalMechanic]

Ish Ish very true. I own several Toyota’s and love them although I’m beginning to question the newer ones. They aren’t as tough as the older ones.

[@ishish9283]

@@ThePracticalMechanic you got that right my friend the old ones are a whole lot better

[@jeronimosantos2632]

Hello all, I was driving on the highway yesterday while elevation was increasing and noticed that at 80MPH on the freeway if the RPM’s were over 4000 consistently for maybe 10 mins, that is when the message came on. I stoped let the engine Idle and then after 15 mins got on the highway again and drove at 70 MPH and the RPM’s never reached over 4000 and the message didn’t come on. I wanted to test of that is the problem and after 1 hour of driving, I stopped waited 15 mins. I was coming up to more elevation increase and that is when I pushed the car again and when the RPM’s were over 4000 consistently , it gave me the alert. I will be more careful and not get the RPM’s that high consistently.

[@natashalyons5488]

I am having this issue right now😢

[@eloyquero4913]

It happened to me yesterday