Temperature

Double check your coolant level, also make sure the cooling fan is coming on at the right temperature, you will need to use a scanner for that they are pretty cheap in amazon.

Sounds like low coolant but if not check the temp gauge the sender could be going bad

Did you get the correct thermostat?

Coolant temperature sensor working?

It was the right one according to Advanced Autoparts. They were all I passed crippling on the way home that day. The coolant level is good. Just hoping and praying it's not a head gasket

Did thermostat have burp nipple? If so did you install it in the up position?

I don't think that it did, no. From what I've been told, the only way to bleed the cooling system on this model truck, is to park the reservoir slightly uphill, and leave the cap off while the engine cycles the coolant. There's no bleeder valve or anything.

So nobody thinks it could be the head gasket? My oil seems clean and I'm not blowing white smoke from my exhaust. I don't know a whole lot about them, other than they're hell to repair

no its not a head gasket, when you drive the temp is good ? if so and you have checked everything else you need to make sure the fan is coming on at the right temp and turning at full speed. also when the truck is at op temp take your hand and touch the rad at the top middle and bottom it should be the same temp in all places, this will let you know if the coolant is flowing through the rad evenly

I'll try that, thanks. Yes though, it never does it when I'm driving. Only time it does it is when I'm parked idling, or in heavy traffic

See if the water pump bearings are good. Free and smooth

Did u find out what the problem was I’m having the same problem with my Silverado 2011 4.8

I never found what was causing it, no. Having throttle issues now. Check engine light comes and goes, saying throttle position sensor. I've changed it 3 times so far. Now their print out for the code is suggesting changing throttle body assembly

Oh man but you think I can drive it far ? Because I been driving it on the freeway and everything and it’s at 210 but just when I’m at a drive through or stop somewhere it goes up to like 225 and the fans go on and it goes back down to 210 u think it’s normal?

I just got the truck I just don’t want it to be something bad !

AntCrisp remove and clean the throttle body then check the throttle position sensor voltage it should be between 0.5 and 1.0 volt if not remove plug covering the base idle screw then adjust to spec. 210 degrees isn't overheating in modern engines as a matter of fact they are more efficient at that temp or even a little higher.

That's what I was thinking about doing before actually replaced the whole assembly

OP, I have the same exact issue with my 2011 4.8 It’s been happening for about 2 years now and still can’t figure it out.. I’ve flushed the coolant, replace radiator, radiator hoses, thermostat, housing, and coolant temp sensor. Has anyone found out how to fix this issue? I’ve taken it to 2 shops and they just say it’s operating at the correct temp while hooked up to their computer. It’s unnerving to not know if I need to pull over or if I’m going to overheat and do some real damage to my engine. They recommend sending my cluster in to Chevy to be tested, but that costs $300 just to be checked out!! I had throttle issue recently as well. I changed spark plugs, wires, replaced the throttle position sensor, air filter, and removed/cleaned the throttle body thoroughly - all super easy to do yourself and it runs/idles perfectly now (besides the temp rising while at idle..)

I would be suspecting the water pump. These can underperform and not leak. Did you or anyone do a head gasket test? Blockage in your heater core? I Just had a similar issue with a Chrysler T&C that I figured out that sounds like yours. Backflushed heater core and burped system for 50 minutes with front end jacked 24” higher than back. Fixed. 2 shops couldn’t figure out

Could you solve the problem? i have the same problem change thermostat sensor for cooland fans and the problem continues

I have the same problem! I've done everything!

AC Condenser

do you have the same problem? with the increase in temperature of silverado?

Yes. Putting a new ac condenser in as soon as it arrives.

thanks brother! This problem in my silverado has cost me a great headache and also to be aware if the silverado is going to heat up!

I’m having the same issue with my 2006 GMC Sierra with the 5.3L having an issue with cooling, truck has the electrical fans. I’ve replaced the water pump, thermostat, coolant change, radiator, engine coolant sensor, ac condenser. I was sitting in the drive through had the windows down with the ac off and saw the temp go past 210 and I shut it off and waited one minute and it was below 210. I’ve tried bleeding the coolant again but no luck. The cooling fans kick on after 210 witch is strange. Runs cool when driving.

I’m having the same issue only in heavy traffic or park. I’ve replaced the thermostat, sensor and relay still a problem . Been on the phone with Jeep I’m trading this in for the Jeep gladiator 2021 eco diesel . Sierra your not my problem anymore . This truck has been good until now , a solid 100k no problems. My Jeep is finally coming here 2021

I'm having the same problem with my 2007 chevrolet silverado. Temp is slightly higher sometimes at stop lights, while idling, etc. Then the fan will kick on and the temp will go down. It also causes the ac to not work in this condition. Ac works fine until engine is allowed to get up to that temp. Then on the highway, the engine seems to get good airflow, and the ac starts to work. I've done the easy stuff - changed the engine coolant sensor, all fan relays and fuses, thermostat, coolant flush. Its never done this and the ac has always been like ice. Tonight, I just sat in my truck and started with a cold engine. Started it up, ran the ac, and just idled in my driveway. The fan and ac were running fine. Then, after idling for a while, the fan turned off and the ac slowly blew hot air. Then, the temp started to rise. Then the fan kicked on and the temp went down, but the ac continued to blow hot air. Something is not right, but I'm not sure what yet.

Air in coolant? Pressure test system for leaks. If none I would start suspecting the water pump.

I have the same problem with my 2007 Silverado temp will go up to 220 fans kick on and it will go back down usually when im going up a steep hill ...... ???? sounds like a wide spread problem, If someone finds the answer for the fix let us know please !!!! I've changed the coolant, hoses, thermostat still doing it . Has anyone changed the water pump and solved the problem ?

Here's the answer that I found for my truck and it worked. It was a loose connection on the AC pressure switch on the evaporator. First, I replaced the switch and thought that was it. Then, I replaced the wired connection and thought that was it. Then I "jiggled" the connector while plugged in to the switch, and it kicked on and stayed on. I got the wires to stay connected and it's worked ever since.

So I have a 2011 Chevy Silverado 4.8L having same problem and trans temp has reached up to 218 on the digital and on the gauge it goes up a lil passed halfway but on my water pump it has a thread to put on a clutch fan so I was thinking of trying that? What ya think?

I considered an extra fan until I found the problem was a wired connection at the AC pressure switch which prevented the fan engaging (and turned off the AC) when at idle or moving slow. This made the engine temp rise until I moved at highway speeds (which naturally cooled the engine). Are you having any AC issues? It might be worth ruling out this problem...

Honestly I’m not having any a/c issues just the overheating problems

But after a while of driving say I go to a Walmart parking lot when I just gently push the gas it jumps to 1500rpm quick then slowly comes down

Not sure about your trans temp. Engine idle problem could be the mass air flow sensor, according to Google.

Look up intermittent idle surge or occasional surge in rpm from mass air flow sensor

Thank ya

Gurulqqdx same problem did you figure out what it was?? Took it to two shops and they said it's running at the right temperature and the fans is kicking on at 220 . . But my temperature gauge goes past halfway when sitting still..

I have seen this many times where radiator is either clogged inside or fan motor does not ramp up to correct speed. It come on but not high speed if ECU is calling for it. Also how old is water pump? Underperforming? I would say 1 of these 3 is your issue.

I have the same problem on my 04 4.8. I was reading on some forums that a bad crank position sensor can cause this.

ECM is delaying the fans. Anything past 210 when fans engage is considered emergency cool down mode in ECM. Also when your vehicle idles high then slowly comes down to normal idle replace throttle body and Accelerator pedal position sensor.

Can you put distilled water or tap water make the big difference supposed to put distilled water if adding antifreeze and water. I didn't see no one say to do this it's worth flushing radiator I'm using distilled water with antifreeze not 50/50 . Had same problem now fixed. Good luck

Really? I’m running Prestone dexcool pre mixed.

2007 Silverado 4.8 Im having the same problem with the overheating at low idle , just like the rest of you . I've had the truck since new and it should run at 210 not over. Anyone figure it out ?? . changed thermostat , flushed radiator & new hoses still the same ...... transmission also shifts hard went out at 59000 miles but was covered under warranty . I am now at 120000 miles and its acting up again . Good Luck !!!

I’m having Same problem after I change coolant from green antifreeze to orange deck cool, I’m thinking it might be blocked because I accidentally mixed the green and orange together

Got the Same problem 2009 Chevy Silverado goes up then down on temperature gauge… since everyone replaced everything BUT the water pump I’m going to replace it and see but it still weird the fans won’t come on until 220