Cooling Issue

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WyoRedNek

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06 tahoe, have replaced thermostat, radiator, fans, water pump....yet it still seems to slightly wanna run a little high still. Doesn't overheat immediately but does after a prolonged day of use. Would this be a bad sensor problem?
 

swathdiver

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06 tahoe, have replaced thermostat, radiator, fans, water pump....yet it still seems to slightly wanna run a little high still. Doesn't overheat immediately but does after a prolonged day of use. Would this be a bad sensor problem?
Welcome to the forum. Do you have castech heads?
 

OR VietVet

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Welcome to forum. Suspect flow problem across condensor not allowing enough air flow but the problem not showing till late in day could be fans sensor or just a bad temp sensor.
 

swathdiver

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Welcome to forum. Suspect flow problem across condensor not allowing enough air flow but the problem not showing till late in day could be fans sensor or just a bad temp sensor.
If the baffling on either side of the radiator or below it has fallen away, this will create the air flow problem that Ron mentions. Too much air goes around the radiator and not through it.
 

rockola1971

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What does "overheat" mean? Temp gauge showing it is running hot? What temp? Coolant overflow tank is boiling over? What we are getting at here is temp gauge could be lying to you which could be a messed up gauge or sensor that feeds that temp gauge. Or you are legitamately running hotter than normal. If you arent boiling over then I would get a scanner on the Tahoe and see what temp is being reported and compare to temp gauge reading. You have Electric fans OR Clutch mechanical fan. Are efans running? Check clutch if you have mechanical fan.
 
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Matahoe

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06 tahoe, have replaced thermostat, radiator, fans, water pump....yet it still seems to slightly wanna run a little high still. Doesn't overheat immediately but does after a prolonged day of use. Would this be a bad sensor problem?

Doesn't overheat immediately? So it is overheating? That's strange.... What are your temps reaching? Sounds like low speed efan isn't working or turning on. Highspeed efam turns on around 230F. Don't go by the dash temp gauge.

Turn off AC so the efans don't come on and park it running at idle. Is that when you notice it getting a little hot on the dash?
 

Matthew Jeschke

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I'm with @rockola1971 need to:

Main thing, verify your temperature and tell us what you get. You can do this with a scan tool to see what computer reports and compare to dash. I'm skeptical of a bad sensor, but you might pull it and see if it's corroded, check it's resistance, etc. If you go that far than heck, I guess why not replace it.

Also check your fan shrouds, etc. etc. etc. as mentioned by others. However, I'm curious did you also run radiator flush through the block and system while you were doing all this work? Motors can get really goobered up and block coolant passages if somebody put in radiator stop leak or any of that stuff.

Another thing, maybe you have an intermittently operating fan. I had only one of two go out years ago, and it overheated at times until I figured out that was it.
 

SnowDrifter

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I'm with @rockola1971 need to:

Main thing, verify your temperature and tell us what you get. You can do this with a scan tool to see what computer reports and compare to dash. I'm skeptical of a bad sensor, but you might pull it and see if it's corroded, check it's resistance, etc. If you go that far than heck, I guess why not replace it.

Also check your fan shrouds, etc. etc. etc. as mentioned by others. However, I'm curious did you also run radiator flush through the block and system while you were doing all this work? Motors can get really goobered up and block coolant passages if somebody put in radiator stop leak or any of that stuff.

Another thing, maybe you have an intermittently operating fan. I had only one of two go out years ago, and it overheated at times until I figured out that was it.
This
Lets sort the nature of the issue before we load up the parts cannon.
OP, if I may, for each part - what was both the reason for replacement of each part, and which part did you replace it with? Product link would be helpful here. Do you have any other special / unique configs on your vehicle? Any specifics on driving conditions when it does read high-temp? e.g. on the highway, sitting in traffic, after coming to a stop, etc.
 

rockola1971

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Ive been jinxed by this thread! Now my temp gauge swings to the right and apparently my Tahoe is running close to 400 deg now! :p

Stupid stepper motors in the cluster are all alomost dead. Now I gotta yank it and rebuild. Guess the set I have on the shelf for it are going to be used. Good thing I bought one of those fancy hot air soldering tools for working on surface mount electronics. They work well for this type of job.
 
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