Ronin7709

Welcome, I am new here so I will appreciate all answers on my problem. I have 2004 Chevrolet TB 4.2L engine, and engine getting hot when I am driving during hot days. When I stay on highway and speed is around 60-70 mph everything is good, as soon as I am off the highway (downtown roads) temp razes to around 230 F, and stay. When I pull over and stay approximately 10 min drops to 210 and stay. No fluctuation.
When the temp is 230 and I will go on highway one more time temp drops to 210 F.

If anyone can help me, I will appreciate it.
Michal

SWHouston

Thermostat not opening fully,
Dirty Cooling System heavy dirt deposits in engine,
Radiator clogged (internal/external), excessive Tube repair/closure,
Hoses deteriorating inside/collapsing, blocking flow,
Improper Coolant Mix,
Captured Air in Engine,
Combustion Gas Leak into Cooling System,
Engine Timing set excessively in advance,
Fuel Mixture too lean,
Bad Water Pump,
Belt slipping,
Air Flow blocked in frontal Air Ram, (forward of Radiator)
Incorrect information from temperature sensor/gauge,
Shroud missing/improperly set to fan positon,
Bad Thematic Clutch on Fan,
Heater bypassed with hose loop,
Excessive temperature contribution from Automatic Transmission, via Radiator Capsule.
Then, a Bad Radiator Cap, but, you didn't mention any major loss of Coolant.

Lots of things to check Michal
Some things more likely than others, but all are possible.

RB Auto Service

230 is not overheating or running hot. I would consider that within the range of normal operation. Many modern engines try to maintain and elevated temperature compared to past engines this is to improve fuel economy and reduce emissions. And many delay the fan actuation to allow the cooling system to operate with the thermostat fully open to reduce drag on the water pump. This strategy also improves fuel economy. To be safe check the coolant level when the engine is cold and look for any leaks. But, 230 would not alarm me at all. The fan on that engine doesn't reach full speed until 264 degrees. And if the coolant type and concentration is correct and the system holds pressure there won't be any boil over at 230 or 264.