Why is my car overheating when my radiator is good

Connie, Were the radiator,water pump and thermostat replaced to try and fix the over heat issue or as maintenance. Engine overheating can be caused by a lot of things, Leak in cooling system, air in system, bad rad. cap, slipping belt, faulty thermostat or installed upside down, faulty water pump, plugged radiator (inside/outside), collapsing rad hose, faulty cooling fan, leaking head gasket, sludge plugging engine water passages, poorly tuned engine, etc..
Take into a good shop for diagnoses and estimate for repair. Check the attached links,instruction and guides, Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."
How to Troubleshoot an Overheating Engine
Steve Litt Overheating Guide
Diagnose Engine Overheating Auto Repair Help
How to Troubleshoot an Overheating Engine DoItYourself com

Anna, thermostats don't fail all that often. If you are overheating after a new one, the problem most likely resides inside the radiator. Radiators can get plugged with gunk over time if they are not flushed at least occasionally. Have you tried that yet?

Does the overheating happen while the car is moving or only when at idle for a period of time?

Is the coolant less than two years old? If it is more, I recommend replacing it after doing a cooling system flush.

If you still experience overheating after that, I recommend having a good radiator shop give it a look.

Good luck.

might be head gasket have a pressure test done and check the coolant for oil and the oil for coolant

Check the radiator cap make sure the seal is good and it holds pressure. Or radiator pluging up maybe circulation is not good.

first step find where the fluid is going
1 if in oilo it has a bad head gasket and possible craked or warped head
and if oil is in radiator same thing headgasket
if leaking else where could be
1. radiator
2. radiator hoses
3. freeze plug
4. heater core leaking in cabin

Overheating can be Because of
1. Bad or No Fluid in Radiator 2. A damage in Radiator / Radiator Fan 3. Chocked air filter 4. bad Quality Lubrication
Make sure your Radiator fluid is filled . make sure Radiator belt is ok and Radiator Fan running well . always use Good Quality Gas . Renew air filter regularly . Check Lube oil Quality.
My Solution above is not a definite advice until it is Physically inspected .
Please Rate my answer Fairly and Support me . Thanks and Regards Deepak Richard

The coolant flush on radiator doesn't do any good. Since you have changed all the key components and still gotten overheated, then the root cause of the problem is the radiator. It got clogged up in small tubes blocking coolant flow. No matter how good the water pump is working but the radiator got clogged up, coolant is not circulating therefore the heat from the engine can't be dissipated to the radiator. Replace your radiator, don't even think about rebuild it. It has been used for 11 years. Make sure to have the correct coolant/water ratio to keep radiator life for years. Good luck.

I had the same problem. My Chrysler LHS kept overheating. I had the thermostat changed out first and it didn't help. Then I had the water pump changed out and still did no good. Then changed out the radiator, still overheated. Come to find out the people that changed my thermostat put it in backwards. Evidently, the thermostats for these cars look different from all the others and people are not sure how to put them in. I took mine to a Chrysler dealer and they fixed it for me.

Two possiblities; a blown head gasket, or a freeze plug leaking. If possible take it to a trusted shop and have the pressure checked on the radiator, they can tell you if your radiator is stopped up, or the freeze plug is leaking, and if it's blowing back in the radiator when you remove the cap then it's a blown head gasket.

start the car from cold,with the radiator cap off.Let the car warm up ,if bubbles apear in the top of the radiator this usualy means the head gasket has gone.

hope this helps.