2007 Tundra Cooling problems

[YJJPWrangler]

07 Tundra with the 5.7l. 173k in the motor. Original everything. Temperature will fluctuate randomly. Driving home today it pegged it in the red zone, warning lights lit up and as I was getting ready to pull over, the gauge went back down rapidly to normal. No acceleration issues, no leaks that I can see. I did check my coolant overflow and it was super low. Could I be getting air pockets in the system due to the low reservoir level?

 

[a_kelley]

No you've got a leak if you're resi was low. Check radiator tank seams, water pump weep holes, & all hose connections, as well as all other fluids for cross contamination. It may be a minor minor leak onto a hot surface to where it burns off before it drips. I would pressure test it if you have access to a kit (advance loans them, hazard fraught sells a decent kit) low fluid level will cause the gauge to ping pong. But if it's low, it didn't magically evaporate.

 

[YJJPWrangler]

Radiator is leaking near the upper inlet hose. New radiator is about $300 from Advance. It's a very, very slow leak. Put a gallon of Toyota red in the radiator/reservoir and no more issues. I'll get around to replacing it eventually. Thanks for the help.