OVER HEATING I HAVE A 1994 PLYMOUTH LASER THAT OVER HEAT'S IF THE SPEED LEVEL IS MORE THAN 60 MPH. WHAT'S THE CAUSE?

Does it "roar" all the time? It could be the fan clutch engaging and the radiator fan spinning at full speed. Watch the temp gauge and the RPM's when it does this..the RPM's should stay the same and the temp gauge should go down. I would also check your coolant level as low coolant cause the engine to run hotter and at highway speed the water will circulate faster making the fan clutch engage due to the extra heat.

I doubt it. I think your tranny is gonna need something ore than that if it made a snapping noise...:(

Check the coolant level. If it's low, what you describe will happen. There is not sufficient coolant to flow through the heater core at idle. At 60mph the water pump is spinning quickly, managing to get some coolant through the heater core, so you get heat until the rpm's drop at idle. If it is due to low level, keep an eye on it to see if it drops again, as you may have a leak.

After the car warms up feel the heater hoses that go into the fire wall from the motor both should be warm if only one is warm and the other is cool the heat valve that opens the flow of antifreeze to the heater core is not functioning locate the valve (either under dash in passenger compartment or in the egine compartment) it has a vacuum line going to it and it should have vacuum when the heat is on if not replace the vacuum line or valve itself. Back flush heater core and also be sure the level of antifreeze is up to the top low antifreeze will cause no heat to occur.

Check your coolant level and check for hoses that goes toward heating element.

Check your trans fluid level, also smell it does it smell burn possible trans problem.Good luck

The first thing to have checked is the wheel balance, if they are good then you need the brake system and wheel bearings checked. Please let me know if this does not help as there are a few more specific problems that could cause vibration.

you need to install a lower temp thermostat. and check the timing too far advanced will also cause this problem

Maybe a little history of maintenance done recently would help, as well as what engine. Like has thermostat been changed, rad flushed, coolant level checked, is rad fan coming on when at normal operating temperature?

A faulty temp sensor for the automatic climate control.