I have a '96 mazda millenia and it overheated on me twice already. I checked antifreeze level and is ok, all fans are running, and no leaks. Any ideas what else can be wrong?

 

Bad thermostat which is not opening to allow the coolant to circulate thru the radiator. Check the front of the A/C condenser & radiator
the fins can be packed with bugs or flatten by gravel which will restrict the airflow for cooling.

 

Where is thermostat on 95 Millenia? I'm having the same problem. Thank you.

 

Do you have the S model with the 2.3l engine or the 2.5l?

 

I don't know engine size, where's that at? It say 24 val. on it. Bought car used. Don't know much about it. It has lots of miles on it. It over-heated last week twice. I took it to Firestone Auto and it wouldn't over-heat there and hasn't over-heated since. Don't know what the problem was. I'm worried it may do it again. I thought it might be thermostat.

 

If you open the hood and look down at the engine do you see any spark plug wires? Does the middle of the engine have a black platic cover on it? Is there a big black platic duct looking thing next to the battery? At the very front over the front valve cover is there a think that looks like a small radiator? If not sure of any of these then send me a PM with you 17 digit VIN # which you can see if looking at the dash from outside thru the windshield in the lower corner on the drivers side.

 

I have a 96 milly too...it's overheating. I already removed the thermostat...threw it in a pot of boiling water andd it opened. I let it Idle for 30 mins pi park and it does fine. I put the parking brake on and let it sit in the driveway in drive and it still doesn't go past half way. as soon as I drive it the needle shoots up and antifreeze begins to shoot out of the overflow hose...I park it but keep it running and the temp. comes back down...anybody got a clue as to what the problem could be???

 

Have you checked the radiator for restrictions. A restricted radiator can often handle the lower heat output demand and flow at an idle but not when rpm's are elevated.
Here is a test for checking a radiator for restriction. Let the engine run for 10 minutes or so at least untill it is fully warmed up. Disconnect the cooling fan connectors so they will not run at all temporarily. Reach you hand down thru the fans or any place that you can reach and feel the temperature of as much of the radiator surface as you can. It should be so hot from top to bottom and side to side that you can not touch for more than a brief second. If you feel areas that are cold or cool to the touch then this is where the restrictions are. No hot coolant flowing to heat up the metal.

Don't forget to plug the fans back in. They are operating once and a while aren't they??

 

thanks man I took the car to the mechanic...he thinks its the head gasket.....Yikes right...he is putting together an estimate for me but before I go there I will check the Rad... I am also gonna try a new radiator cap....I hve that miller 2.3 so I really can't afford the 2 grand for a head gasket job... question if the head gasket was bad would that cause the coolant to be forced out through the overflow???

 

" Thinks " it is a headgasket?? For that kind of money he better be damn sure!!!!!! Yes a headgasket could cause that kind of condition if the gasket was blown between the combution chamber and cooling system passages. You would also see a fairly continuous stream of bubble from the filler opening even at an idle. Have never in 17 years seen a blown headgasket on a Millenia S. Make sure that is an accurate diagnosis before condeming the car.