2004 Chevy Tahoe temp issues

[Robbie3]

Have a 2004 Tahoe and I had it for about a year and the water pump was previously replaced before I purchased it and since then I’ve replaced the radiator first after that ran fine for a few months then the heater core T fittings started to leak replaced those with the metal ones instead of the plastic ones and once again it was fine for like a week or two was running between 180 and 210 never going above 210 but recently I was driving and I noticed sitting still it would stay at that temp but driving or turning the ac on while driving would spike it up and it would jump from between there to 220 and would just fluctuate back down and then go back up so I replaced the thermostat and housing and gasket and it’s still having the same problem if anyone could help as to what the problem could be thanks

 

[Fless]

Some of that temp swing is normal, as long as you're looking at a scan tool, not the dash gauge.

Has it been converted to electric fans, or does it still use the clutch fan?

If the clutch fan, are both sections of the fan shroud (top and bottom) in place and secure?

If the clutch fan, warm up the engine and shut it off. Try to move the fan blade with your hand; it should be very difficult if not impossible to turn it. If it turns easily when the engine is warm, it's time to replace the clutch. Stick with OE since we've heard complaints that aftermarket clutches are much noisier.

 

[nonickatall]

I had a similar problem before and was searching for a solution.

In my case, it was a corroded connector on the temperature sensor located on the steering pump.

After unplugging and replugging the connector a few times, the faulty connection was fixed, and my temperature has been stable ever since.

And as for the temperature fluctuations: I had a cheaper thermostat, and my temperature also fluctuated slightly.

While troubleshooting, I installed a better thermostat, and my temperature has been stable ever since.

 

[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.