2017 silverado 1500 V6 4.3L

Noah H9 · January 21, 2024

So I have a 2017 Silverado 1500 V6 4.3. My transmission temperature gets very high at times even driving 10 to 20 minutes. I installed the superior solutions bypass valve but nothing has changed temperature wise. Then doing some research I realize that a lot of people are saying that the 4.3 won’t help with the superior solutions because it does not have an aux trans cooler. My first question is that correct? And my second is what else can I do to lower the temp?

CamGTP · January 21, 2024

I believe you are correct, there isn't a factory cooler like the V8 trucks.

You can install an aftermarket cooler to help with temps. But if only 10-20 min worth of driving is getting the transmission hot, you may have other issues. But you also didn't say how hot it is getting either.

newdude · January 21, 2024

1 hour ago, Noah H9 said:

So I have a 2017 Silverado 1500 V6 4.3. My transmission temperature gets very high at times even driving 10 to 20 minutes. I installed the superior solutions bypass valve but nothing has changed temperature wise. Then doing some research I realize that a lot of people are saying that the 4.3 won’t help with the superior solutions because it does not have an aux trans cooler. My first question is that correct? And my second is what else can I do to lower the temp?

How high we talking? Over 195-205F?

Noah H9 · January 21, 2024

Yes, if I drive for a good 45 mins we will be in the 200 range.
as of right now, I don’t see it settle until it gets up to that range, it just continues to get hotter and doesn’t just rest.

Noah H9 · January 21, 2024

Yes, if I drive for a good 45 mins we will be in the 200 range.
as of right now, I don’t see it settle until it gets up to that range, it just continues to get hotter and doesn’t just rest. Sometimes if I drive 15 mins it will be around 145 but like I said it just continues to climb.

Almost like the radiator isn’t cooling it off?

CamGTP · January 21, 2024

Technically seeing 200 degrees isn't an issue as the fluid can more than handle that temp but the fluid life is reduced.

It's always going to continue to climb if you don't have a real transmission cooler installed. Install an aftermarket cooler and the temps will stop going as high.

And you are right, the radiator won't cool it off because the coolant is staying at 200 degrees.

Edited January 21, 2024 by CamGTP

Grumpy Bear · January 21, 2024

The V6 transmission cooler is in the cold tank which will run 25 to 35 degrees cooler than the thermostat temperature. Factory water thermostat is 207 F so the cold side will run something like 175-ish. Transmisson fluid cooler inside the cold tank is a 6 or 7-plate stacked plate exchanger that runs 'counter current' to the fluid which means it will get within a few degrees of the cold side tank temperature. I'm guessing you live somewhere that is currently quite hot as on a cold Midwest day here it takes a very long time to reach operating temperature. If fact in the current subzero conditions, it won't.

In town it may run a bit warmer or on a very hot day or with a big load or running very fast. Don't know where you are or how you drive so I'm guessing a bit.

Check the simple stuff first. Kinked lines. Plugged cooler. Is the water temperature 'normal'. Fluid level. Fluid condition. Stuff like that. If it all checks out good, then this like will buy you about 25-30 degrees. It requires no programing and is drop in and as reliable as the factory unit.

Katech 174 Degree Gen 5 LT Thermostat (katechengines.com)

I run a similar setup in my 2015 V6 with very good results on any day under 100 F. Fact is, the ATF never gets hotter than 145F on any day under 75F. Cheaper and easier than a cooler. Which can also be added down the road. I'll be adding more this spring. We have plenty of days over 75F.

You have more than 40K on that fluid? Change it.

Noah H9 · January 21, 2024

1 hour ago, Grumpy Bear said:

The V6 transmission cooler is in the cold tank which will run 25 to 35 degrees cooler than the thermostat temperature. Factory water thermostat is 207 F so the cold side will run something like 175-ish. Transmisson fluid cooler inside the cold tank is a 6 or 7-plate stacked plate exchanger that runs 'counter current' to the fluid which means it will get within a few degrees of the cold side tank temperature. I'm guessing you live somewhere that is currently quite hot as on a cold Midwest day here it takes a very long time to reach operating temperature. If fact in the current subzero conditions, it won't.

In town it may run a bit warmer or on a very hot day or with a big load or running very fast. Don't know where you are or how you drive so I'm guessing a bit.

Check the simple stuff first. Kinked lines. Plugged cooler. Is the water temperature 'normal'. Fluid level. Fluid condition. Stuff like that. If it all checks out good, then this like will buy you about 25-30 degrees. It requires no programing and is drop in and as reliable as the factory unit.

Katech 174 Degree Gen 5 LT Thermostat (katechengines.com)

I run a similar setup in my 2015 V6 with very good results on any day under 100 F. Fact is, the ATF never gets hotter than 145F on any day under 75F. Cheaper and easier than a cooler. Which can also be added down the road. I'll be adding more this spring. We have plenty of days over 75F.

You have more than 40K on that fluid? Change it.

Thanks so much. So the link you sent me I don’t think will fit my truck. I have a 4.3L and it doesn’t show that the thermostat will fit that? Do you know of any other ones that will fit my truck?

Grumpy Bear · January 21, 2024

51 minutes ago, Noah H9 said:

Thanks so much. So the link you sent me I don’t think will fit my truck. I have a 4.3L and it doesn’t show that the thermostat will fit that? Do you know of any other ones that will fit my truck?

It fits.

Ubiquity · January 21, 2024

Thanks to Grumpy and others, I got my 2015 v6 work truck sorted out.

If by some chance they are out of stock and you can't wait, you might consider this as an alternative: Mishimoto MMTS-VET-180 Racing 180 Thermostat fits Chevrolet So far it has proved itself to be of value.

Noah H9 · January 21, 2024

1 hour ago, Grumpy Bear said:

It fits.

Awesome!! And you think this is will help lower my trans temp?

Noah H9 · January 21, 2024

1 hour ago, Ubiquity said:

Thanks to Grumpy and others, I got my 2015 v6 work truck sorted out.

If by some chance they are out of stock and you can't wait, you might consider this as an alternative: Mishimoto MMTS-VET-180 Racing 180 Thermostat fits Chevrolet So far it has proved itself to be of value.

Side question. I recently installed the superior solution bypass valve but it’s not keeping the temp down as I would like. After installing the new thermostat like you said should I replace the bypass with the original part and return the superior solution one?

Ubiquity · January 21, 2024

Noah H9: I also first did the SURE COOL SYSTEM SUPERIOR STL010; then I followed it up by converting to the lower temperature thermostat. I had not even considered returning it to the original setup.

I haven't towed much with my truck, so I can't say how it would keep up with shedding the excess heat. If I were to tow on a regular basis, that is, anything of considerable weight, I think I would be adding an additional aux radiator. But as it stands now I'll cross that bridge when and if that time comes.

I also plan on changing my transmission fluid on a tighter schedule. I currently have a total 65k easy miles on the truck; and if I recall correctly, its about 1k miles since I changed the fluid/filter and did the bypass valve.

Edited January 21, 2024 by Ubiquity
My English teacher said I should try it again.

Noah H9 · January 21, 2024

5 hours ago, Grumpy Bear said:

The V6 transmission cooler is in the cold tank which will run 25 to 35 degrees cooler than the thermostat temperature. Factory water thermostat is 207 F so the cold side will run something like 175-ish. Transmisson fluid cooler inside the cold tank is a 6 or 7-plate stacked plate exchanger that runs 'counter current' to the fluid which means it will get within a few degrees of the cold side tank temperature. I'm guessing you live somewhere that is currently quite hot as on a cold Midwest day here it takes a very long time to reach operating temperature. If fact in the current subzero conditions, it won't.

In town it may run a bit warmer or on a very hot day or with a big load or running very fast. Don't know where you are or how you drive so I'm guessing a bit.

Check the simple stuff first. Kinked lines. Plugged cooler. Is the water temperature 'normal'. Fluid level. Fluid condition. Stuff like that. If it all checks out good, then this like will buy you about 25-30 degrees. It requires no programing and is drop in and as reliable as the factory unit.

Katech 174 Degree Gen 5 LT Thermostat (katechengines.com)

I run a similar setup in my 2015 V6 with very good results on any day under 100 F. Fact is, the ATF never gets hotter than 145F on any day under 75F. Cheaper and easier than a cooler. Which can also be added down the road. I'll be adding more this spring. We have plenty of days over 75F.

You have more than 40K on that fluid? Change it.

Side question. I recently installed the superior solution bypass valve but it’s not keeping the temp down as I would like. After installing the new thermostat like you said should I replace the bypass with the original part and return the superior solution one?

Noah H9 · January 21, 2024

59 minutes ago, Ubiquity said:

Noah H9: I also first did the SURE COOL SYSTEM SUPERIOR STL010; then I followed it up by converting to the lower temperature thermostat. I had not even considered returning it to the original setup.

I haven't towed much with my truck, so I can't say how it would keep up with shedding the excess heat. If I were to tow on a regular basis, that is, anything of considerable weight, I think I would be adding an additional aux radiator. But as it stands now I'll cross that bridge when and if that time comes.

I also plan on changing my transmission fluid on a tighter schedule. I currently have a total 65k easy miles on the truck; and if I recall correctly, its about 1k miles since I changed the fluid/filter and did the bypass valve.

What’s your trans temp at now? Better?