the motor overheats after about 30 mins of driving i checked the radiator and theres antifreeze in it but the resevoir is full also. no leaks anywhere either. could it be the thermostat or the temp sending unit??? the fan doesnt turn on and someone i kno said worse case senario is that its a blown head gasket is this troo. i just bought this motor and the motor is still in my freinds car that i am driving until it goes into mine. i want to make sure its all straight b4 i swap it. any insight of diagnosis will help.
thanks

 

Definitely check to see if your thermostat is opening up.

 

Does it overheat when you are sitting there?

if it does, it could be the fan motor, fan relay, fan fuse, or fan switch.

Does it overheat when you drive?

if it does, its the thermostat, or a leak somewhere, or air bubbles in the coolant.

touch the radiator hoses, both lower and upper. Are they warm? Did you bleed the air out when you filled it with coolant?

Take the thermostat out (PM me if you need help) and put a string around oen end (end without the 'bulb') and the other end to a pencil. Put the pencil over a pot of water, and make sure the thermostat hangs in the water without the bulb touching the bottom of the pan.

Around...i think 190 degrees or so, the thermostat should open up and you will see the rubber seal open.

If the rubber is already open, the thremostat is stuck open. If it never opens, its (duh) stuck closed.

PM me if you need help
Sebastian

 

thanks for the insight imma check it out actually today lol b4 i go out with the car.

 

Alright...lemme know what you gather