Jump to content

Recommended Posts

Posted

New to site and first time owning a truck. Unsure if this is normal or not

 

2012 GMC Sierra 1500 Crew Cab 4.8L 4x4

Truck runs at about 108 degrees for normal running transmission temp when in 2x4 which is low from what I am reading. When I put it into 4x4 temps jump to 150-155 degrees. Today when parked in 4x4 temps starting increasing into the 180 range and only had it in 4x4 for maybe 1 mile. I turned off the truck to let it cool down and put it back into 2x4. Temps started to drop down to the 140 range. Is this normal for both my normal running temp of 108 in 2x4 and fast increase when in 4x4?

Posted

I've never personally tried to watch my transmission temps when in 2WD and in 4WD, mainly because I leave the truck in 4AUTO if it's snowing.

 

But it does make sense that the temps get higher because the engine/transmission is working harder with 4WD engaged. I wouldn't be worried at those temps at all. Unless you are seeing 215-220+ on the regular basis in 4WD, there is nothing to worry about.

 

I can barely get above 100-110 degrees in my short commute to work in the winter time. Takes long trips just to hit 130's right now.

  • Like 2
Posted

You have got to remember when you are not moving you are not getting the airflow across the coolers so that may be some of the issue. 
 

I was always told about 100 degrees over ambient is normal temperature under normal driving. 

  • 1 month later...
Posted
On 1/8/2021 at 7:41 PM, Gray Fox said:

You have got to remember when you are not moving you are not getting the airflow across the coolers so that may be some of the issue. 
 

I was always told about 100 degrees over ambient is normal temperature under normal driving. 

This is likely what you're experiencing. I hauled an enclosed trailer from KY to VA and noticed exactly this as I was monitoring the trans temps. When I was driving on the interstate, temps would be fine. As soon as I got off an exit to get gas/food, the temps would start to rise. On short fuel stops, the temperature would actually be higher after I restarted the truck to leave. This is because the fluid where the sensor is located, was absorbing the heat from the trans. Temps never got too hot but, it was interesting to watch them rise and fall with vehicle speed and the fan kicking on and off. What was really wild was watching how quickly they dropped when it started raining.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Latest Articles

  • Posts

    • You need a better code reader/scanner.  You are missing codes.  Did the dealer give you a copy of the SAVI scan from that visit?     If the fluid hasn't been changed, change it.  Shudder will likely go away.  
    • TLDR to my other post...   Hard. Pass.  Too many what ifs.     Are you set on a 3.0 Duramax?  Have you considered anything not GM just in case?  If you don't have to have a pickup, lots of other options for $27,000 out there.   
    • I see some red flags.   - No mention in the Carfax if the oil pump belt was changed.  LM2s had a 150,000mi service interval, and its got 164,245mi on it.  So right out the gate it needs about $3000-3500 for that to be done before driving it another 150,000mi.  Belt is at the rear of the engine.     - If something happens to the transmission valve body, the special coverage is expired by mileage.  That will likely be an out of pocket expense, with zero or near zero GM participation if something happened even though its in by time.   - 2020 LM2s seem to need timing chains after 80,000mi at some point.  They fixed this end of 2020/starting 2021 model year engines.  They will usually set a P0016 I think?  There is another $8000-10,000 if it needs a chain.  The main chain is at the back, secondary at the front so the pump belt would be done at the same time if it needed chains.     - Long oil change intervals.  7,000-8,000mi on average, probably close to 0% or perhaps to or beyond 0% on the OLM.  Lots of them not at the dealer which makes me wonder how much of the oil ran through that truck was the proper Dexos D rated 0w20 oil and not just gas engine 0w20, which is not the same at all.     - Long fuel filter changes, again likely taking the fuel filter life to 0% or more.  First one went 28,603, second was done 43,094 miles later at 71,697, from there another 46,452mi to 118,149mi, and then the most recent one 37,026mi later at 155,175mi.  So counting its original fuel filter, its had only 4 fuel filters on it.  No bueno IMO.         Good news?    - It has had only two warranty trips to the dealer.  The first free service (end of December 2020 on the Carfax), and the transmission reprogram recall (end of August 2025 on the Carfax).     - Truck did a LOT of moving, so that might explain the lack of emissions related repairs like bad NOX sensors, bad exhaust temp sensors, bad glow plugs, etc.         The "emissions system checked" could just be how something was flagged for Carfax.  GM dealers have to do SAVI reports for warranty repair orders so they scan the truck.  So its possible that is there for that?  
    • Thank you, @Z45!   NOTE - No all repair shop/Dealers reports to Carfax   That is my main concern.  The CARFAX looks way too clean for a 6 year old anything with 164,245 miles.  Even something known for reliability (like many Toyotas) typically has a lot more replaced, like a Nav screen, interior trim, shock/strut, or brake pads.  And surely the last set of tires (installed at ~58k miles) would be bald unless those were all highway miles.   I'm tempted to pay a local dealer to look up the VIN, but am not sure if that will be worthwhile.  Last time I did this, it was 100% useless, and I felt scammed - they noted the bumper was replaced years ago and that's it.  A 5-year old could spot the accident damage, even though nothing was on the CARFAX.   After giving the dealer a call, the truck may have a hard shift, but they have to verify with their mechanic if that's even a concern.  And I've test driven about a dozen of these now, many near Chicago, and half the trucks shift hard/odd at all throttle positions.  The ones with aftermarket lifts/larger tires shift terrible, and 3 stock trucks shifted so violently I thought the transmission valve body was going out.   At this point I'm conflicted, as I need a vehicle, and am coming up short locally.  Northern trucks in this price range tend to have either multiple owners, a lot of mods (lifts/oversized tires without re-gearing), and are generally in rougher shape.   If this truck showed up in your neighborhood for $27k and you had to purchase it sight-unseen, with the possibility of needing a 10L80 rebuild, torque converter, or rear end - would you do it?  I'm convinced most of the 10L80 trucks I test drove are broken, they can't all shift so bad, with massive flares/slipping/lurching and mis-matched downshifts like a teen driver learning stick.
    • From the spy shots, the front end does look like it's borrowing some styling cues from the Canyon. I'm more interested in the powertrain news than the screens though. If the 3.0 diesel survives into the next generation, that alone will keep a lot of current owners interested.  
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...