Over heating

Pacco · #1 (**permalink**) 09-29-2007, 07:07 PM

Changed thermostat, now the engine is overheating. Was running 180 - 195. Took it out tonight and shot up to 240 in about 5 minutes of running. Running a 180 thermostat just like the one I replaced. What could be the problem?

ST · #2 (**permalink**) 09-29-2007, 07:34 PM

Make sure you didn’t install it backwards.

patrickt · #3 (**permalink**) 09-29-2007, 07:35 PM

If your car was not overheating before you replaced your thermostat, you probably just got a bad new thermostat -- you could also have air in the system as well I suppose. It's very easy to test your thermostat. What I would do is pull the new one out and put the old one and the new one in to a pot of water on the stove and heat them up and watch them. If the new one is bad, it will be obvious.

Bill Spain · #4 (**permalink**) 10-02-2007, 07:14 PM

Bet you have air in the system. I had the same problem when I put in a new thermostat. Solution: ran it until it heats up, shut it down and let it cool. Add more coolent and repeat three or four times.

Pacco · #5 (**permalink**) 10-03-2007, 04:08 PM

Thanks for the replies. Changed thermostat housing and made sure the thermostat was seated properly. Since I don't have a inline filler or expansion tank. I held the upper radiator hose as high as it would stretch. Filled system until coolant came out of the thermostat housing. Drove it for a while and bled the system of any remaining air. I think I will invest in a expansion tank or inline filler.

barabar · #6 (**permalink**) 10-03-2007, 05:21 PM

Have to go with air in the system. Drill 1/8 hole in thermostat. ( some come with the hole.) Make sure it is in the part that opens. Also some thermostats have a wider opening. Before installing a thermostat you should always test it with a blow dryer or boiling water. If it is air the top radiator hose remains cool even though the gauge reads 180.