Why does my car over heat ..no leaks..good radiator..full coolant?

(2010-05-30 10:41:42)

1. Sione Says: when i drive it over heats after 30Min's of driving go on the free way doesn't make a different / and i took out the thermostat i drive for an hour and same thing it over heats to about 225 to 235 then i drive on the free-way and then it cools down then stop and let it idle then same thing it over heats again after like 20mins of letting it idle then i drive then it goes down just a little .... Wat do u think is the problem ....its a 1995 Oldsmobile 88 LS v6 3.8 series 2...non super charged..with 94k mi

2. Richard D Says: First thing to check is electric fan if it has one. See if it goes on when the car is hot. Watch the coolant with the cap off and the engine warm enough for the thermostat to be open--you should see it moving. If not, possibly the water pump is bad, but they usually make noise.
Second, flush the cooling system. You can have it reverse flushed or you can add a flushing chemical. run it like that then drain and replace coolant. This will usually work.

3. The Fear Says: Do a radiator flush and change the thermostat. It could be your thermostat is not working, change it. And a faulty fan souldn't cause it to over heat that quick.

4. Andy Says: sound like the cooling fan is not working. next time it heats up tap the cooling fan motor and see if it start working. It also could be the relay or the switch.

5. Yaz Says: No thermostat & still heating , have the Radiator checked for flow it could
be plugged, Does the electric fan come on. if it doesn't that's your problem.
Once car reaches 186 degree fan should cycle on and off.