coolant high temperature
I have an 04 trail blazer. Yesterday a high coolant temperature warning message came on and the temp gauge had moved from 210(normal) to 260 (red zone). I shut off the engine and checked under the hood. Coolant reservoir was full. No apparent leaks anywhere. After cooling down I removed radiator cap, radiator full. I restarted and drove home, about 20 minutes, with no problem. Left engine idling for about 30 minutes. No problem, normal temperature, cooling fan running. Any thoughts?
It could be a few things. Maybe your thermostat was sticking. The relay for your fan could be going out or the sensor is going bad. Unfortunately it is hard to tell with the one occurrence. If it happens again, check to see if the fan is on. then feel the upper radiator hose and see if you feel coolant going through it. No coolant could mean that the thermostat is stuck.
Or, perhaps the pump has decided to stop working.
Originally Posted by Pikey
If the coolant has never been flushed, now might be a good time to do it. The factory fill is only good for 5 years.
And, if your doing the flush, that would be a good time to toss the old t-stat.