2016 temp gauge not working and fans running high speed

[Jasper2307]

Hi all, long time lurker but first time posting. I have a 2016 Tahoe LTZ that has a new issue that happened tonight. The wife and I had an appt about 7 miles from our house. On the way to it everything was fine, however on the way home about halfway I heard the fans kick on. Did think anything was wrong just the fans running. Then I noticed the temp gauge hadn't move from 0 degrees. I stopped to check to see if it was actually getting hot. It was stone cold. The overflow tank was at normal level and just barely warm. We finished the ride home pulled in the driveway and I checked again, still cold! Also the fans were running full tilt engine off. I restarted it a couple of time no change. fans on and temp gauge didnt budge. As I was looking for the fan relay to pull it the fans shut off after about 10 minutes with the engine off. Also no CEL light. Any Ideas before I waste more money at the dealer? Thanks in advance!

 

[Miami-Dade]

You need a new Thermostat. Happened to me on a long trip. Took it to the Chevrolet dealer. They flushed out the radiator also as they said it overheated. Just happened to my friends 2017 Tahoe as he was on a long trip. He took his to the Chevrolet dealer.

 

[Beeker702]

In

You need a new Thermostat. Happened to me on a long trip. Took it to the Chevrolet dealer. They flushed out the radiator also as they said it overheated. Just happened to my friends 2017 Tahoe as he was on a long trip. He took his to the Chevrolet dealer.

Once you replace the thermostat your gonna need a scan tool to clear the code even tho the check engine isn’t on

 

[Jasper2307]

Thanks for the replies. It seems that this is a common problem with these 5.3s. I'll be changing it as soon as I can find a thermostat. They seem to be in rather short supply right now. Probably will change the coolant temp sensor at the same time. I'll let you know how it goes. Thank for the help!

 

[p1zaul]

https://www.napaonline.com/en/p/THMHT207518

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[Bagherra]

This exact same thing happened to me this morning.
Temp gauge went to 0 and fans kicked on. Pulled over and fans ran for about 5-10 min. Restarted, and temp came back to normal.
And no CEL...

So this is the thermostat goin bad?

Btw, this is a 2016 Denali...

 

[jimbmorris67]

Anyone know the logic in the system that when a thermostat is stuck open, the fans get kicked to full speed? The computer must know temperature didn't get to operating range quickly enough so it kicks the fans on to max cooling as a fail safe?

 

[Fless]

The logic is probably determining that there is a possibility that the coolant temp sensor is malfunctioning, so it goes to failsafe. Just a WAG on my part, but it makes sense in my small brain.

 

[TChas999]

Hi all, long time lurker but first time posting. I have a 2016 Tahoe LTZ that has a new issue that happened tonight. The wife and I had an appt about 7 miles from our house. On the way to it everything was fine, however on the way home about halfway I heard the fans kick on. Did think anything was wrong just the fans running. Then I noticed the temp gauge hadn't move from 0 degrees. I stopped to check to see if it was actually getting hot. It was stone cold. The overflow tank was at normal level and just barely warm. We finished the ride home pulled in the driveway and I checked again, still cold! Also the fans were running full tilt engine off. I restarted it a couple of time no change. fans on and temp gauge didnt budge. As I was looking for the fan relay to pull it the fans shut off after about 10 minutes with the engine off. Also no CEL light. Any Ideas before I waste more money at the dealer? Thanks in advance!

This is NOT a thermostat issue. It is the temperature sensor which is a very easy fix. Follow this link for step by step instructions. I just fixed mine with no issues, in less than an hour.