Overheating Troubleshooting (She won't stop overheating cap'n)

Driving down the highway, I noticed the temperature of my car is running pretty hot. I pulled off to the side of the road and looked at the reservoir and it was empty of fluid. I quickly put fluid into the container and continued to drive. However, I noticed that the car was STILL running hot. So, I set up a date to get the car repaired. While the day approached, I constantly check the radiator fluid levels, but the fluid levels were staying pretty consistent. I go over to my friends, open the housing of the thermostat and notice that the thermostat is in a couple of pieces. We remove the thermostat (I am pretty sure we got all the pieces), and put a in a new thermostat.

At this point, the car is STILL running hot. So we think that the thermostat may be bad. We open the housing again, but then notice that there is very little fluid in the area. We remove the thermostat completely, and put the housing back together, run the car for a little bit and then check to see if any fluid is moving through the system by disconnecting the upper hose. All that the house had was a lot of air under high pressure.

At this point, I notice that the reservoir fluid level is slighty lower then when I filled it. (But the temperature has been very different when I was checking it) At this point, I believe that it is the water pump is broken for two reasons:

-> Faulty water pumps have a leaky weep hole

(My friend is unsure how much fluid is actually coming out if any)

-> It makes a light squeaking sound

(I may be thinking that I am hearing it)

However, the water pump is VERY difficult to replace and it looks new (bought this car from a family member a couple years). Right now, I am looking for any other alternatives before I resort to this. Ideas?

You are losing antifreeze. It could be the water pump,head gasket, or you could have a leak you have not found. You could also have been losing it by overheating due to a bad thermostat, and are now overheating because you never got the radiator full. Put a gallon jug of the proper 50/50 coolant in your trunk. When the car is cold remove the radiator cap, not the reservoir cap and fill to the brim.Repeat every time the car is cold until you remove the cap and it is already full. Then fill the reservoir to the cold level. Keep an eye on the reservoir level and if it keeps going down you have a leak, then get the radfiator pressure tested to find out where it is.If it doesn’t gow down wait a few days and pull the rad. cap to make sure it is still full.

@oldtimer_11: sounds like a possibility. However, I did fail to mention that these “repairs” have been over a course of 4 weeks which (at the end of the 4th week) is when I glanced at the fluid levels again. So maybe there is a leak, but it is very small too. However, I do think that you are on to something… Will report back with the results this friday

Checking for a failed head gasket or water pump is quite easy. Those two things should be eliminated before extensive repairs are undertaken…

Hint. If your cooling system stays pressurized even when cold, suspect a blown head gasket. After two or three driving cycles, the radiator should be full to the brim when cooled overnight. If you remove the radiator cap and find it low, but the overflow tank is normal, suspect a blown head gasket. To check the water pump, remove that thermostat one more time and replace the housing. Remove the upper hose from the radiator. With the radiator full, direct the open end of the hose into a bucket and start the engine. The coolant should be pumped out with considerable force, especially if you rev the motor a little…

If the head gasket and the water-pump check out, replace the radiator…

Damn The Cooling System, Full Speed Ahead, Cap’n ! . . . Not.

Sorry. When you replaced that thermostat you did follow instructions for purging the system of air, correct ? Also, the thermostat can’t go in backwards, right ?

What model year and engine are featured on this Tempo ? Maybe all the other Tempo drivers have some advice for you.


Putting fluid in the overflow reservoir would not help because that fluid is only sucked back into the system when the engine cools down.
A broken thermostat is unusual, but Replacements are sometimes defective. Running without the thermostat will only cause your system to heat up more slowly than with one.
The low fluid level accounts for the hot air in this complaint.
You lost fluid somewhere, and not into the overflow tank. It could be a pin hole in the radiator, or a leaky hose, or a blown head gasket, or a bad pump. was there coolant on the deck?
Once you had a cold engine, and filled the radiator (not the overflow tank), most of the air in the system should have been gone, esp. if you filled it when the engine was running. If not then it most likely is the pump. Just because the pump is new does not mean the impeller is still turning. Is your fan belt slipping to cause the squeeling sound? Is the lower hose collapsed? Generally speaking the coolant pump is cheaper than a head gasket to replace. Have you run a compression check on the head to see if you have a gasket problem? Is there coolant in the oil (milky oil).