in hot weather speedometer stops off and on?

Here is a guide that can get us started on the right foot. It sounds like the VSS is going out or the instrument cluster

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please run some tests and get back to us so we can continue helping you.

What I mean by heating up is the air temp. When it's 70 or above weather air temp it starts to act up. In the cold air everything is fine. I feel between air temp and vehicle operating temp is over heating what ever is the cause. Winter months never acts up. What I mean by acting up is : Speedometer starts to go up & down then goes to zero when at zero get a lag in performance and the engine lite comes on. Shut vehicle off it cools down everything goes back to normal engine lite is off runs great until it heats up again. Thank you for your time and help.

Okay that makes sense, lets run the codes to see if there is a temperature sensor that is acting up.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please let us know what you find.

Cheers, Ken