I have an 89 f150 5.0 efi, I pointed an infrared temperature gun at my thermostat and that was running at 197 degrees.. normal... previously my spark plug wires had burned up on the truck and I pointed the gun at my exhaust manifolds which read 500 degrees... Is something wrong here? I cut some 3/4 inch heater hose and put it over the plug wire boots at the plugs to protect from burning the wires. I also noticed my drivers side doesn't have an exhaust manifold heat shield, my passenger side does.

Thanks

Edit: I forgot to add we are speaking in degrees Fahrenheit here thankfully.

 

Sounds perfectly normal to me.

 

lick your gear selector and all will be known