Engine overheating

There is a pattern that is occuring. As I said, I drive mostly on the freeway betwwen my office and home. Each is located right off the freeway. Car does fine, because I am drivng with steady air flow. Once I get off and in stop and go traffic, it over heats. Something is not working at that point in time. But all has been checked per dealership. They had my car for the last week running it, testing it, and it did finally act up as they called it; it started over heating. They called me and told me they found the problem a short in the cluster, that when the needle indicated it was over heating, it actually was not, the motor never got over a certain temperature. They replaced the cluster and tested the car another two days running it; and it did fine. They called me today to pick it up said its fixed. I picked it up left, getting on the freeway; dealership is located off freeder road, I'm driving home going 65-70 mph 20 minutes exit off freeway going 55 pmh come to first light its green make a right. Continue on to the next light stop light turns go. Driving up the road, traffic starts slowing then come to a stop; looked down at temperature gauge it now rising over the half way mark (a/c is on whole time) traffic is inching, gague is continuing to rise. At the stop sign the needle has risen 3/4 of the gauge and still rising. I'm now thru the stop sign and again moving; needle starts going down. I hit another traffic pocket in front of my subdivison needle starts to risie again, it over the 3/4 of the gauge and closing in on the H. Light changes I start moving the needle kind of set there, then began to go down. Again by he time I reach my driveway the needle is down about normal.

Did you ever get this issue resolved and do you know what the problem was?

I have a 2006 Sonata and have been experiencing the same issue. After driving the car for awhile and then hitting a stop and go situation, the temperature gauge climbs up to the H! The engine gauge rises more when the car is stopped than it does when it goes.

All fluids are new in the car.

My wife has an '05 4cy Sonota. This past summer, her car started overheating. Same story, had the car towed to the dealership. We got the car back, 2 days later, guage showed running hot again. We always drive with the a/c on in the summer time in Mobile, AL. Took the car back several times, the dealership put a whole new cooling system in the car (water pump, thermostat, radiator ect.) Gauge still would read hot. My father in law has an on doard diagnostics tool, so he and I took it for a spin. Conclusion: when the a/c compressor cycles on, the temp gauge on the dash rises but the engine coolant temp on the computer stays constant, never overheating. Anyone have any ideas?

Took the 2004 Sonata to my Hyundai dealer and luckily a Hyundai certified tech was there working on another vehicle. He instructed the dealer that this was an issue with wires shorting that he'd seen on other Hyundais. They tested the temp of the engine and found the engine's temp was where it was suppose to be but the thermostat showed overheating. The thermostat was reading the short. They replaced the wires and shrink tube and send me on my way.

Here are the tech notes: "Top Engine Ground Wire had High Resistance. Removed and replaced ground wire."

Will be doing a long drive this weekend. Hoping the issue won't pop up. Will post again if it does.

Took a trip to LA (over 200 miles each way). Over mountains, in Stop and Go traffic, and open highways. Had no temperature problems and believe me I was watching the gauge the entire way. I'm calling the issue resolved: "Top Engine ground Wire."

Thanks sharken4cer for your experience.I did nearly the same but add 'extras ground wire' and it succeed with flying colours. Now, it's the second day of success and hope to be continuous to the day after until I sell of the car in the next few years. Thanks again.

Can anyone direct me to where to locate this top engine ground. I traced battery cables but still not sure is the one that has given y'all such success. Any help is appreciated!