Jump to content

Recommended Posts

Posted (edited)

So I have a 2017 silverado 5.3 with 102,000 miles and for some reason i cant figure out my truck overheats when i drive or put the pedal to move it over heats but at idle its back to normal.. I have put 2 thermostats in a temp sensor and flushed and filled the rad from the hose method so there would be no bubbles or air in the system.  Has anyone had this issue and could give me some pointers?? Theres no leaks anywhere the rad is full of fluid new thermostat new temp sensor im just at my wits end

Edited by ChrisM24
  • Replies 45
  • Created
  • Last Reply

Top Posters In This Topic

Posted

If i keep my foot on the gas driving for say 1 minute or 2 it will peg out hot. Or if i floor it for a few seconds it will peg out hot unless i let off the gas and it will cool down some. It stays over 210 the whole time for sure. So i have to drive on and of the pedal to keep it from getting to hot

Posted

Either the water pump can't keep up or the radiator is lacking flow.

 

That is what I'd be looking at.

Posted

Do you think the water pump went bad but just never leaked water? Ive never had that happen before and the rad i dont know what would cause it to not flow this whole thing came on a few weeks ago before that everything worked fine

  • ChrisM24 changed the title to 2017 silverado overheating while driving and normal at idle
Posted

When i did all that before it seemed to work ok. It really didnt overheat but after awhile i took the cap off one morning to top off the fluid and ever since then its back to getting hot. I put a new cap on yesterday but it made no change. Has any of this happend to any of you? I could really use some help.

Posted

Check cooling fan operation, if fans are coming on, then could be a minor head gasket leak, look for "steam sludge", pull the oil filler cap and look for "Chocolat sludge" on the cap.  If not evident, still could be head gasket problem.

Posted

It could be. Ive checked the oil and its not milky im not loosing antifreeze theres no leaks or anything dripping on the ground. I do know that when i cut my truck off my fans will run for alittle while after i cut the truck off. 

Posted (edited)

When you refilled the cooling system, which coolant did you use? And did you bleed air out of the cabin heater coil? 

In your idling, driving, and revving experiments, does the coolant level drop at all? Are you losing coolant?

 

On 6/26/2022 at 10:37 AM, ChrisM24 said:

Do you think the water pump went bad but just never leaked water?


A water pump doesn't have to leak to be bad. The impellor can, and has, spin/crack off the shaft and not pump anymore. I agree with CamGTP, if you're positive you used the right coolant, and you properly bled the entire cooling system including the heater core, then something is prohibiting the coolant from being pumped, or allowing it to dump the heat. The rad is easy to check, pull off the supply and return hoses, and you can check for communication, water goes in, water goes out, but that does not guarantee it can move the right amount of coolant through it, ie proper flow rate. 

Edited by stu_pidasso
Posted

I agree. Im changing the water pump right now. When i drained the fluid out the section of the reservoir that says rear still has fluid in it. Isnt it all supposed to drain out when you take the drain plug out??

Posted
2 hours ago, stu_pidasso said:

When you refilled the cooling system, which coolant did you use? And did you bleed air out of the cabin heater coil? 

In your idling, driving, and revving experiments, does the coolant level drop at all? Are you losing coolant?

 


A water pump doesn't have to leak to be bad. The impellor can, and has, spin/crack off the shaft and not pump anymore. I agree with CamGTP, if you're positive you used the right coolant, and you properly bled the entire cooling system including the heater core, then something is prohibiting the coolant from being pumped, or allowing it to dump the heat. The rad is easy to check, pull off the supply and return hoses, and you can check for communication, water goes in, water goes out, but that does not guarantee it can move the right amount of coolant through it, ie proper flow rate. 

When i flushed it the first time i didnt bleed the heat coil. To be honest i didnt even know about that or where to do it. As far as loosing coolant goes my tank has been just under the full line this whole time so i assumed it wasnt flowing and im using orange antifreeze mixing half and half concentrate

Posted
7 minutes ago, ChrisM24 said:

When i flushed it the first time i didnt bleed the heat coil. To be honest i didnt even know about that or where to do it. 

 

Well, don't go tearing apart the water pump and replacing it right now. This is a huge step that you missed the first time around that can cause exactly what you're experiencing. In order to bleed the heater core, the best way is to start your truck and set the heat and fan speed to high, as high as it will go, and let her rip for a few minutes. Air locking a closed loop can do exactly what you have going wrong. 1AAuto's YouTube has a lot of GM content, and has videos on how to bleed the system properly. I know its a GMT900, but the concept is the same, and the engine set up is mostly the same. Do it right this time, and if you're having trouble still, then start working it. 

 

18 minutes ago, ChrisM24 said:

I agree. Im changing the water pump right now. When i drained the fluid out the section of the reservoir that says rear still has fluid in it. Isnt it all supposed to drain out when you take the drain plug out??

 

Nah, there will always be pockets and areas of the cooling system that do not drain out even though everything is higher than the drain. Old Honda D series engines rads sit way lower than the block, but when you drain the rad the block is mostly full. Makes for a refill that requires care. I would personally use Dex-cool, I try not to screw around with coolants and just buy it right from the dealer. Your owners manual should tell you how much volume you need for coolant, if it wants 10L, and you put in 7L and the reservoir is full, well... 

Posted
2 minutes ago, stu_pidasso said:

 

Well, don't go tearing apart the water pump and replacing it right now. This is a huge step that you missed the first time around that can cause exactly what you're experiencing. In order to bleed the heater core, the best way is to start your truck and set the heat and fan speed to high, as high as it will go, and let her rip for a few minutes. Air locking a closed loop can do exactly what you have going wrong. 1AAuto's YouTube has a lot of GM content, and has videos on how to bleed the system properly. I know its a GMT900, but the concept is the same, and the engine set up is mostly the same. Do it right this time, and if you're having trouble still, then start working it. 

 

 

Nah, there will always be pockets and areas of the cooling system that do not drain out even though everything is higher than the drain. Old Honda D series engines rads sit way lower than the block, but when you drain the rad the block is mostly full. Makes for a refill that requires care. I would personally use Dex-cool, I try not to screw around with coolants and just buy it right from the dealer. Your owners manual should tell you how much volume you need for coolant, if it wants 10L, and you put in 7L and the reservoir is full, well... 

roger that. Ill do some looking up on there and do my best. Ill keep you posted when i get done and see if it worked.

Posted

Coolant flows through the heatercore all the time, there really isn't a special way to bleed the system.

 

I run it up to temp with the expansion tank cap off, turn it off for a few minutes, let it bubble, add coolant and cap the system. Done water pumps on many GM trucks without an issue.

Posted
41 minutes ago, CamGTP said:

Coolant flows through the heatercore all the time, there really isn't a special way to bleed the system.

 

I run it up to temp with the expansion tank cap off, turn it off for a few minutes, let it bubble, add coolant and cap the system. Done water pumps on many GM trucks without an issue.

So you don’t actually have to bleed the heater core?

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

    • It is possible to add your own 12v outlet to your truck.  Check out this video:   I verified via GM Upfitters that pin 31 is the same on the 1500 trucks.  The wire is GM part number 84779405.   You can get the GM 12v outlet from Amazon  https://www.amazon.com/Genuine-Accessory-Receptacle-25774623-13549530/dp/B0F1H9YRGF EWAY 12 Volt Power Adapter for GM   https://www.amazon.com/EWAY-Chevrolet-Silverado-Cigarette-Ignition/dp/B0915RRW6Q/ref=sr_1_1?   I just haven't figured out a good place to put the 12v outlet in my truck.   Some people are getting USB-C to 12V adapters  https://www.amazon.com/WYMECT-Cigarette-Lighter-Socket-Adapter/dp/B0F87WNQKB/ref=sr_1_1_sspa? Not sure if they provide the correct amperage that a device like a tire inflator would need.  
    • Thanks; I looked there a few minutes, and I think I can find something. I really never looked there, as I thought it was stuff like PTO/aftermarket bodies/accessories like snow plows.
    • This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • 2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...