My LS5 454 engine temp runs between 220-240. Is that too hot? When I idle the temp lowers to 220 but driving increases it to 230-240. When I slow down it lowers back to 220. Any suggestions?
Thanks

That is too hot. First check the radiator for corrosion in the tubes. If they are blocked the engine will run hot in traffic as the unblocked vanes are not enough to handle the heat of the reving engine while at idle thy can keep up.

An engine running to lean will also have possible similar conditions. Pull the plugs. If they are near white in color you are too lean.

Where are you taking the readings from, the head or the intake?

Are you sure the gauge is accurate?

Fixed...thanks guys. Pulled the radiator, replaced the core, new tanks on both sides, replaced the sending unit and thermostat.

Now she is running 180 all day long!

Thank you!

Also read somewhere certain brands of sending units for guages can be as much as 40 off. I think the AC brand?

New temp readings from engine and gauges!