1990 Other Plymouth Models Overheating

DAEDRUS

MEMBER
1990 PLYMOUTH
4 CYL
FWD
AUTOMATIC
100,000 MILES

Hi. I have a 1990 Plymouth Sundance 2.2L and has been overheating whether in city on highway. It is not leaking antifreeze and both radiator and reservoir have adequate coolant. I replaced the thermostat and radiator cap. The top radiator hose is warm so I know the coolant is circulating. When driving it will heat up to extremely hot (though I stop the car/engine before it overheats) then i'll stop and sit for a while and sometimes it will cool normally, sometimes it will heat right back up. My cooling fans do work and come on properly. Could it be the sending unit to the gauge is bad?

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,192 POSTS

Hi:

Yes it could be the sending unit. To check, you'll need a thermometer that reaches over 200 degrees.

With the engine cold, remove the rad cap and place the thermometer in the rad so you can see it. Start the car and allow it become hot. When the gauge starts going too far, check the thermometer. Normal operating temp is between 195 to 205 degrees. Compare the collant temp and the interior gauge to determine if the sending unit is the problem.

If it's working correctly, replace the cap and follow the same process with the cap on. Check the rad hoses. Specificly the lower one. Make sure it isn't collapsed restricting the coolant from circullating. If it or another one is, replace it.

If that isn't the problem, I would recommend that you remove the radiator and have it boiled out. Most likely it's plugged.

Joe
PS: I hope I helped you. If you have any other questions, don't be afraid to ask.