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Transmission temp

Thatguy233
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Thatguy233 New Member

Thatguy233

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How's it going , new to forum and hoping someone could shed some light. I have a 2019 silverado custom 5.3 w/ 6 speed trans with about 37k. A month ago  the truck threw error p0741, it  would Rev high and not want to shift so dealer replaced tcm and new fluid.  A few weeks past and code comes back with trans temp running around 215* when it did so dealer replaced torque converter  and said it was good to go. I took for a extended  drive of so.e city and a Lil hwy for around d 1hr and Temps climbed to 225*.  Is 225* high? Doesn't seem normal and dealer is saying they. Ant find anything wrong 

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Thatguy233 New Member

Thatguy233

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How's it going , new to forum and hoping someone could shed some light. I have a 2019 silverado custom 5.3 w/ 6 speed trans with about 37k. A month ago  the truck threw error p0741, it  would Rev high and not want to shift so dealer replaced tcm and new fluid.  A few weeks past and code comes back with trans temp running around 215* when it did so dealer replaced torque converter  and said it was good to go. I took for a extended  drive of so.e city and a Lil hwy for around d 1hr and Temps climbed to 225*.  Is 225* high? Doesn't seem normal and dealer is saying they. Ant find anything wrong 

CamGTP Senior Enthusiast

CamGTP

Posted
Posted

That is high for standard driving. Without load just driving around they are usually around 180-195 and it's pretty typical to see 210-225 while towing.

Thatguy233 New Member

Thatguy233

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Temp probably  would have kept climbing   But I pulled over to cool it down Dealership is telling me nothing wrong with my truck

Edited by Thatguy233
Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted

Mine use to do that then I bypassed the thermostat and BINGO. Runs 160 F on 95 F days. (Not towing). 

JimCost2014 Senior Enthusiast

JimCost2014

Posted
Posted
2 hours ago, Thatguy233 said:

How's it going , new to forum and hoping someone could shed some light. I have a 2019 silverado custom 5.3 w/ 6 speed trans with about 37k. A month ago  the truck threw error p0741, it  would Rev high and not want to shift so dealer replaced tcm and new fluid.  A few weeks past and code comes back with trans temp running around 215* when it did so dealer replaced torque converter  and said it was good to go. I took for a extended  drive of so.e city and a Lil hwy for around d 1hr and Temps climbed to 225*.  Is 225* high? Doesn't seem normal and dealer is saying they. Ant find anything wrong 

How much powertrain warranty left? Do you have a backup ride to get to work?

 

Drive it till it dies (transmission) or go get a second opinion from a better dealership who values your business.

 

Sometimes they will balk at inheriting someone else's crappy work/attitude, but some will. 

MRP Enthusiast

MRP

Posted
Posted
9 hours ago, Grumpy Bear said:

Mine use to do that then I bypassed the thermostat and BINGO. Runs 160 F on 95 F days. (Not towing). 

Hi Grumpy Bear, I have been following you posts about the thermostat delete.  Tried to find the exact posts again, but could not by managed to find the thread.  I have a 2019 GMC with the 8L90 box. 30000km on the clock so far and no issues.  Wanting to keep the truck for as long as possible, I have been following threads about the problems experienced with this transmission.  I came across your threads on the thermostat delete and have been going through them with interest.  Having originally come from  Africa where keeping transmissions cool whilst working them hard was a top priority.  I found it interesting that GM put a thermostat in the cooler lines.  It just so happened that yesterday I had to take a trip to the nearest town, 250km away so I thought I would watch the transmission fluid temp in line with what I had read in your posts.  The ambient temp was 35F.  Transmission was 64F when I took the truck out the garage.  I had driven for 2 hours and covered 190km before the transmission temp reached 169F.  It stayed there for the remainder of the trip.  The trip on the way back was pretty much the same with the ambient temp having gone up marginally to 40F.  Transmission temp remained the same.  In this case, the thermostat would not have even opened?  I was surprise that it did not build more heat, and was even more surprised, as you have said previously how long it takes to get to running temperature.

 

With thermostat removed I can see how it would warm up more quickly pulling heat from the radiator as you mentioned.  Under the conditions above, what do you recon the truck would run at with the thermostat removed?

 

Something else that I have been doing some research on is the proactive upgrading of the oil from the current Dexron HP to the improved Mobil 1LV ATF HP now rather than the planned 70000km based on the problems experienced with these boxes.  Speaking to GM they are sort of downplaying it.  Have you any thoughts or experience with transmission oils and any thought on additives like Lubeguard that are meant to improve oil and transmission performance? 

 

Although I still have three years left on the drivetrain warranty, I do not want to allow a problem to start now, that I will have to live for for the life of the truck.  Similar to your outlook on longevity of the vehicle and doing that's right now to ensure this.

 

Any insight greatly appreciated 

Thatguy233 New Member

Thatguy233

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Thanks for input,   Yeah I'm thinking when that torque converter was going out it also started doing damage to the tranny.   I got about 23000 miles left on the warranty

JimCost2014 Senior Enthusiast

JimCost2014

Posted
Posted
20 minutes ago, Thatguy233 said:

Thanks for input,   Yeah I'm thinking when that torque converter was going out it also started doing damage to the tranny.   I got about 23000 miles left on the warranty

Take it to another dealership while it is still covered by GM.

Black02Silverado Senior Enthusiast

Black02Silverado

Posted
Posted
59 minutes ago, Thatguy233 said:

Thanks for input,   Yeah I'm thinking when that torque converter was going out it also started doing damage to the tranny.   I got about 23000 miles left on the warranty

As stated above, I would take it to another dealer. 

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