Jump to content

2017 Silverado 5.3 - Temp Gauge Fluctuation

Mr. Pibb

By Mr. Pibb
in Troubleshooting & Recalls

 Share

Recommended Posts

Mr. Pibb Enthusiast

Mr. Pibb

Posted
Posted

Need Help Please!!!!  I truly appreciate anyone that reads this long post.  Hopefully someone can help me figure this out.  

 

Bought my 2017 Silverado CrewCab LT Z71 new.  For 5 yr & 10 mo. the temp gauge sat at 210 with no issues and no variation. Then, in June 2023 the temp started rising about 10 degrees and would fluctuate from there back to normal. 

  1. Thermostat was replaced, didn’t resolve the issue.  
  2. Temp sensor was replaced, didn’t resolve the issue. 
     

Truck is well maintained, radiator/coolant flushes done a normal intervals with no issues found. 

 

Dealership has checked out this issue 3 times and says it’s operating as normal, temp fluctuation is normal.

 

I have been calling BS on this since June, how is this normal? Almost 6 years with no variance but now it’s normal?  

 

So here I am in October, with continued temp issues that are anything but “normal” The temp gauge has progressively increased, the gauge goes up to 245-250 then will drop back down to 210 and fluctuates between 210 - 230/235 as the drive continues.  

 

Things to note:

  1. I have never had a Check Engine light, adding to the frustration. 
  2. Coolant level doesn’t change, no leaks whatsoever.  
  3. This temp issue does not happen when idling.  I’ve idled for 20-30 min both from cold and after driving with the issue happening, no fluctuation. 

 

I have thought through some other possible issues but then wonder could it be “this” when the issue is not consistent or throwing codes. 

  • Are the active shutters not opening / operating correctly, that should throw the check engine light 
  • Belt is loose, again should be a more consistent issue with sounds and other functions having issues.  
  • Water pump going out, again I think that would cause more consistent issues and would overheat the engine.  
  • Fan(s) going out, wouldn’t that be more of an issue when idling vs driving and would be a more consistent issue.  
  • Could this be some other sensor, relay, electrical issue. 


Any help, experience, and/or suggestions you have on this issue are greatly appreciated. 

 

rav3 Senior Enthusiast

rav3

Posted
Posted

How many miles on it. Have any modes been done?

mikeyk101 Senior Enthusiast

mikeyk101

Posted
Posted

I agree that something is going on. If you were hauling a trailer in some more challenging areas, the higher temps would make sense. But if you are just driving around in average areas, I agree that it's not normal. In my case, last winter, my OEM thermostat went bad and my dash gauge wouldn't get up to the 210⁰ like it had done for years even on the coldest days. I decided I wanted to change from the OEM 207⁰ to an aftermarket Motorad 194⁰ thermostat. I switched to a cooler one because I sometimes tow a toyhauler and had experienced some higher than normal temps especially in areas with steep grades and figured if the thermostat opened a little sooner, the radiator would help with keeping coolant cooler. It worked well for a couple months and the dash gauge showed the steady 210⁰ all the time. Then several months after installing, I experienced the motor running hotter than normal especially when running at higher speeds or accelerating a little faster than regular. I switched it out for an OEM 194⁰ that is found in several Corvettes and Cadillac CTS models and haven't had a problem since. Dash gauge normally stays at the 210⁰ except for occasional temp increases when towing toyhauler in more challenging terrain.

 

 

One thing I would mention is that the dash gauge is very generic. When it shows 210⁰, the coolant can actually be anywhere from 185⁰ to about 225⁰. So if it moves higher, it is already well past the 210⁰ temp. The best way to monitor the current coolant temps is through an OBDII reader. I use a BAFX Bluetooth reader and Torque Pro app on my phone.

 

But yours is odd. I'm wondering if maybe the replacement thermostat is defective? Any chance you are having an issue with your cooling fans running all the time?

  • Like 1
Mr. Pibb Enthusiast

Mr. Pibb

Posted
  • Author
Posted

I had experienced the fans running even after the engine was off before the temp sensor change.  They still seem to be running more than usual but haven’t been running after the engine is off.

  • 9 months later...
2018z71midnight New Member

2018z71midnight

Posted
Posted

Hi there, did you ever resolve your issue with the fluctuating temp I am having the exact same issue you are. I had the dealer do a full coolant flush and fill and also have them change the thermostat and housing to OEM and the fluctuation hasn’t changed. I’m afraid that when I do end up towing it will exceed past the recommended operating temperature, any advice would be much appreciated. Thanks. 

Edgar Salvatierra New Member

Edgar Salvatierra

Posted
Posted

I'm havi.g the exact same issues and can't find the problem did a thermostat change from the oem to 160. Also new tempsonsor and also a new radiatir fan assembly and still won't resolve the issue. Dealer told me they can't reproduce the problem.

Buckwild27 Enthusiast

Buckwild27

Posted
Posted
6 hours ago, Edgar Salvatierra said:

I'm havi.g the exact same issues and can't find the problem did a thermostat change from the oem to 160. Also new tempsonsor and also a new radiatir fan assembly and still won't resolve the issue. Dealer told me they can't reproduce the problem.

There's a good chance the head gasket is bad. Are you loosing coolant at all? The direct injected engine is harder to diagnosis a bad head gasket if it's a tiny bad spot. Coolant won't show up on spark plugs and most likely won't get in the oil pan. 

Yotaman Enthusiast

Yotaman

Posted
Posted

My 2014 temp started fluctuating down from 215 and back up while running a few years ago. I did  search and found out the thermostat was defective. I think GM updated maybe to a new part number. I replaced mine and no issue since. Search for radiator cracking it was caused by the cycling T'stats.

Yotaman Enthusiast

Yotaman

Posted
Posted

My 2014 temp started fluctuating down from 215 and back up while running a few years ago. I did  search and found out the thermostat was defective. I think GM updated maybe to a new part number. I replaced mine and no issue since. Search for radiator cracking it was caused by the cycling T'stats.

 

Found this from when I swapped mine may help

Mr. Pibb Enthusiast

Mr. Pibb

Posted
  • Author
Posted

I have not been able to resolve the issue.  I continue to be told that it’s “normal”.

 

This issue continues to puzzle and frustrate me.  I’ve read the comments about head gaskets, radiator leaks, etc and that’s solid information but I have a wrench to throw in that.  

1st, I  have no coolant loss and 2nd,

Wouldn’t those issues persist at any and all times when the engine is running (Hwy, City, or Idle) which is not the case here. This is happening during acceleration, from a stop light/sign, getting on the hwy, or passing.  
 

I’m obviously not an expert and I apologize if I sound like an idiot here. I still think this could be the fan or shutters. Fan doesn’t show any issues on a diagnostic. However, maybe someone can answer this;  If the fans are functioning but either the high / low speed isn’t, (I believe the fans have multiple speeds) would that show on a diagnostic.  Basically could it not be operating correctly but enough to fool the diagnostic.

 

2nd idiot question, I know the dealer has told me if there is any issue with the shudders, it will immediately throw a check engine.  Well is it possible they are not opening as quickly as they should, allowing the engine temp to climb higher than expected.  
 

The aftermarket thermostat is an interesting thought.  I guess the question here is are there any negatives to running a 160 vs. OEM. I know several have noted that this didn’t fix the problem but maybe it would at least help counter the higher temps until the issue is identified. 
 

I truly appreciate all the time and info provided by everyone.  I hope that a clear resolution can be found & documented at some point to help everyone impacted. 

Buckwild27 Enthusiast

Buckwild27

Posted
Posted (edited)
6 hours ago, Mr. Pibb said:

I have not been able to resolve the issue.  I continue to be told that it’s “normal”.

 

This issue continues to puzzle and frustrate me.  I’ve read the comments about head gaskets, radiator leaks, etc and that’s solid information but I have a wrench to throw in that.  

1st, I  have no coolant loss and 2nd,

Wouldn’t those issues persist at any and all times when the engine is running (Hwy, City, or Idle) which is not the case here. This is happening during acceleration, from a stop light/sign, getting on the hwy, or passing.  
 

I’m obviously not an expert and I apologize if I sound like an idiot here. I still think this could be the fan or shutters. Fan doesn’t show any issues on a diagnostic. However, maybe someone can answer this;  If the fans are functioning but either the high / low speed isn’t, (I believe the fans have multiple speeds) would that show on a diagnostic.  Basically could it not be operating correctly but enough to fool the diagnostic.

 

2nd idiot question, I know the dealer has told me if there is any issue with the shudders, it will immediately throw a check engine.  Well is it possible they are not opening as quickly as they should, allowing the engine temp to climb higher than expected.  
 

The aftermarket thermostat is an interesting thought.  I guess the question here is are there any negatives to running a 160 vs. OEM. I know several have noted that this didn’t fix the problem but maybe it would at least help counter the higher temps until the issue is identified. 
 

I truly appreciate all the time and info provided by everyone.  I hope that a clear resolution can be found & documented at some point to help everyone impacted. 

As I stated in my post bad head gasket is harder to diagnosis on the direct injection engine. No it doesn't present itself all the time, it's mostly present under a load. My truck is a 2014 I don't have shutters, it has the same problem the dealer said it was a head gasket. A mechanic friend of mine said it is the head gasket. As far as the thermostat goes I don't like these thermostats and will eventually swap it and the housing for one I'll include a link for it. The 160° will work fine if you are south of the Mason Dixon or in California. Northern winters with a 160° thermostat you won't have any heat coming out the vents. Also the truck needs to be tuned for the 160° so the fans work properly and it doesn't throw codes for not getting to temp fast enough. 

 

https://www.montmotorsports.com/dms-billet-thermostat-housing-w-ls3-style-160-degree-thermostat-gen-v-lt/

Edited by Homewrecker007
  • 2 months later...
Kolbert1922 New Member

Kolbert1922

Posted
Posted

Hello all, I am also having this same issue with my 2017 Sierra with the 6.2. I have gotten both the radiator and the thermostat replaced and it still continues to fluctuate up and down, above 210. I’m not what I should check next. I had a 2014 with the 5.3 and it always sat a little below the 210 mark and never moved from there. Just trying to see what the next step should be. So irritating!

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
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      In the 80's 90's I'd run Honda's 7,500 miles between changes using Red Line HP 5W20 and do it for hundreds of thousands of miles with issues. Back in the day it was an SAE 20 with the HTHS of a SAE 30 and SN add load. It was also very polar. Oxidation VOA was over 120. Besides those motors were SPFI and lean burn tech. I could have likely run it longer but never did.    We had a Toyota bought new I ran on Pennzoil's latest and greatest synthetic of the day with "Penthane". A made up word for a very low dose of PAO. Tried 7,500 mile OCI's in that Group III/VI chemistry and the rings tapped out at 90K. Rocker box wasn't as bad as the one Punch put up but it wasn't good either. Also a SPFI motor.    I'm around 3,750 across the board on these GDI monsters and the oil it tapped out by then usually on TBN/TAN crossover and color. Red Line HP Euro.    The AMSOIL SS brochures tell you to follow the OEM values for the service class but that it can be run up to 25K if monitored. I can't imagine what motor could go that distance and not tap out. I've never owned one.    Yes, I know. Lot's of people do. I'm just not going to be one of them. 
    • Grumpy Bear
      OCI, not when but why?

      By Grumpy Bear · Posted

      I knew a guy in the early 80's that bought a new Monte Carlo and ran it a 100,000 miles without ever changing the filter or the oil. Just kept adding. It looked like that inside.     
    • whenindoubtuseahammer
      My First Project and GMC has me stumped

      By whenindoubtuseahammer · Posted

      Good evening. I was lucky enough to get passed down to me a 2007 GMC LBZ that was my great uncle's. While the underside and rockers are more or less gone I feel like with time I can restore it to working order since it only has 110,000 miles and he put nearly every option he could get without getting the new body style since he did not trust DEF. So far I have done everything I can think of but when I put the key into the ignition nothing happens. I put 2 brand new batteries in it. Cleaned the terminals. Check all the fuses and relays and they all pass with my multimeter. I know I'm missing something that I just cant think of. The only odd thing is the OBD2 port works which makes me think its not the mega fuse. Any advice would be greatly appreciated. 
    • PunchT37
      Casey from the Texas Hill Country

      By PunchT37 · Posted

      Looks nice. I still have my 2000, 1500. Bought a 2025, 1500 for retirement. Feels solid. These trucks have a bad rap on the internet. My brother has a `24 1500, 5.3 with 52,000 miles. No problems at all. Mine hasn`t either but mine`s only at 12,700 miles. Have seen some of these things with 100,000 miles with no problems.
    • Fish_truck
      Casey from the Texas Hill Country

      By Fish_truck · Posted

      Howdy! New to the forum of course! My name is Casey, just picked up a 2024 high country midnight edition. First “new” truck in 24 years for me. Driving a 1998 Z71 since 2002. Have been on the GMT400 forum with lots of good info and help there. Nervous about driving these newer trucks and all their electronics…. Did a lot of work on the Z71 myself over the years. New truck is definitely a nice upgrade after 24 years. Photo of the old and new, still keeping the Z71 - has 320,000 miles on her and still running well!  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...