doyodoyo

Recently my car (94 ls400) over heats after I replaced timing belt , water pump and thermostat . I thought it is due to air in the system and bleed the system so many times. In the process of bleeding I observed my electric cooling fans wont run( with the a/c on or heater on) and too much water like a cup full of water(not the red color type coolant) from each tailpipe each time I increase the RPM to complete the bleeding. This is not the usual condensation though it is cold out side(like 40F - 50 F). when I drive the car for test the car over heats again and the low coolant warning sign shows up on the cluster. Then I checked coolant level and it was okay. The low coolant sign went off but comes back even while the car runs on idle. when I run the car and hold the upper radiator hose it doesn't feel coolant is passing through although it it warm and not pressurized enough. The lower radiator pipe feels cold too.when the engine gets to its operating temperature coolant level rises inside the reserve tank and steams also comes out of the reserve tank. My heater is working good.
what I did; checked 120 alt and 30 amp fan fuse it is okay. unplug the temp sensor on the radiator lower part, the fans runs or okay. replaced the sensor and turn on the heat the heat woks good but not the electric fans.I turn on the a/c the fans wont run . I am not sure if a/c supposed to run with the ambient temp of (40F - 50F); the cars a/c minimum temp setting is 60F. I did dye(blue to yellow color ) coolant test on the reserve tank result is good. I pressured tested the cooling system and reserve tanks cap result are good no leak. engine oil good no coolant in it. checked few spark plugs for coolant no sign of coolant on it. checked thermostat inside boiling water it is good (opens).
car drives good but I do not want to drive it while it overheats and with low coolant warning light and no fans running.

If you have suggestion like bad head gasket or bad water pump or bad thermostat or bad temp sensor on radiator or blocked radiator please provide your reasoning behind it so that I can do more sense giving test. I need your valuable help. Thanks

PureDrifter

iTrader: (10)

Did you put the thermostat in the right direction and orientation?

How exactly did you bleed the system?

doyodoyo

Yes I followed lexls.com tutorial. thanks.

doyodoyo

For bleeding first I drain(not necessary) about gallon of coolant from the radiator end. and filled the coolant again properly through the Bolt(on top of the engine) and some more into reserve tank. I tighten the Bolt back and left open the cap on the reserve tank. I let the engine run for some time occasionally revving it. The fan did not come event though the engine is hot. I also open the heater(high) on low blower speed. Did this more than two times by turning the engine off and wait and on like that.

doyodoyo

Should I just replace the sensor on radiator and the reserve tank cap(tested okay, but I see few cracked line on rubber inside of it)? Do you think It matters on my original problems?

PureDrifter

iTrader: (10)

Doesn't sound like it's bled properly. Try buying/borrowing a bleed funnel. Also called a "spill-free funnel". Using one with the correct (included) adapter will remove any questions about air in the system. Make sure to have the heater on max when bleeding otherwise you'll get a large bubble in the heater core.

doyodoyo

Thanks for the suggestion. I am still working on it . Doing what I did before once again. How do i tell if coolant circulates or not on this car. This car has do not has radiator cap ; it only has reserve tank cap and it is impossible to see if coolant circulates. I did not want to remove the upper radiator pipe from the radiator inlet just to see if coolant circulates.(it is gone be too much mess if it circulates ).

doyodoyo

how one knows if the water pump pumps or works? I have no leak, no noise and my coolant fan wont run. Checked the coolant switch it works, relay , fuse are all okay including the fan. I am suspecting hot coolant do not get to the coolant switch on the radiator. am I not reasonable to suspect the water pump? the radiator, hoses are not clogged.