please help.....overheating problems

[JoeMechanic]

Swap the relay from the box with another one that has the same configuration and or part number staped on the side or bottom.Most of the relays are interchangable from one to the other.If that doesn't work than the relay must be good..replace the fan switch..that should do it.Here are some part#'s for you from advanceautoparts.com..they are for reference.Engine cooling fan switch..there are 3 types depending on your wiring. 1.part#35967 one wiring terminal is green
2.part#35969 2 terminal switch both being gray wiring
3.part#35972 2 terminal swicth both wiring is purple

Relay Part#'s RL36621 must be ordered 1 day turnaround $2.79
or Relay# 35795 $8.88 ordered as well

Coolant Temp Sensor Part# TS25381 $7.99 must be ordered 1 day turnaround
2.Part# TSU81 $11.88 IN STOCK

1993 Lumina 3.1...If I messed up on the year and engine size ..then you must look these parts up yourself,Joe.

[JoeMechanic]

Part #'s

Swap the relay from the box with another one that has the same configuration and or part number staped on the side or bottom.Most of the relays are interchangable from one to the other.If that doesn't work than the relay must be good..replace the fan switch..that should do it.Here are some part#'s for you from advanceautoparts.com..they are for reference.Engine cooling fan switch..there are 3 types depending on your wiring. 1.part#35967 one wiring terminal is green
2.part#35969 2 terminal switch both being gray wiring
3.part#35972 2 terminal swicth both wiring is purple

Relay Part#'s RL36621 must be ordered 1 day turnaround $2.79
or Relay# 35795 $8.88 ordered as well

Coolant Temp Sensor Part# TS25381 $7.99 must be ordered 1 day turnaround
2.Part# TSU81 $11.88 IN STOCK

1993 Lumina 3.1...If I messed up on the year and engine size ..then you must look these parts up yourself,Joe.

[Eric's93z]

joe i have a 95 lumina 3.1 4 door sedan.........were exactly is this fan switch on the car? i work for chevy so i would like to get the gm number on this thing but ill take what i can get.....the techs over here didnt even mention a "fan switch" they claim it could be a computer or a bad wire that connects to the computer

[JoeMechanic]

Look up Air Compressor cut-off switch.This switch cycles the compressor but also works in conjunction with your radiator fans thats why they have 2 or 3 wires.It should be mounted somewhere by the AC compressor or just follow the AC harness back until you find a round about a quarter sized switch.I don't know exactally..but I could go to the library and look it up at alldata online for you.I am doing research on engines as I have a 1995 grand am in my driveway with half of the engine apart and just found a broken camshaft on it.Also Advance lists a connector and wiring for this switch which tells me they have had problems with the wiring maybe that will do it..Part#PS37541 connector.I would replace both since they are cheap enough and see what happens..but stay put I am going to the library now its 5:30 pm est..I should give you more info after 8 p.m. check back for an update,Joe.

BTW the part#'s that I checked for the 1993 are the same for a 1995 3.1..not much changed in 2 years with that engine.If worse comes to worse my dad has a 1999 LTZ 3.8 lumina that I can check out to find this switch.

[JoeMechanic]

Umm..I think I goofed

I am at the library and found some info on the ECT(Engine Coolant Temp Sensor).Alldata say's that when the car overheats it can put the ECT out of calibration.This sensor is mounted in the thermostat or water pump housing..it is either a 2 blade or 3 blade connector.It seems as though they have had problems with this wiring also..so I would suggest to replace the conector going to this sensor as well as about a foot or so of the wiring(I think the wiring part number is correct that i gave you earlier).Here is the OEM part numbers for this sensor. 2 blade(yellow and black wiring) part#15326386 $30.40 3 blade(don't know wiring colors?)part#10096181 $26.88.It describes the sensor as being close to the fuel rail closest to fuel pressure regulator mounted in either the thermostat housing or water pump housing?.It has a labor rate of 0.3 warranty and 0.5 standard..which can't be that difficult to change.It also say's you should diagnose with a scan testers temp reading and either and hand held electronic temp tester pointed at radiator or engine or another coolant temp tester to see if readings indicate overheating or not.If not you may just have a malfunctioning gauge in your car.Sensor should be tightened no more than 10 ft pounds and use thread sealant tape on the threads.Change this sensor and the connector and wiring and see if that cures the problem,Joe.

[bszopi]

http://wiki.60degreev6.com/index.php?title=Detailed_Sensor_Descriptions#Coolant_Temperature_Sensor_.28CTS.29

[Eric's93z]

hey guys i found out the problem with my car and it was fine all along, my temp gauge was defective, the fans came on at 220 with the coolant hose blocked! other wise it ran at 198 200, the car is fine......so my next project is to recalibrate this gauge b/c it says its running hot when its not. i was told to buy some resistors and sauder it in between the gauge and the sensor.....so my question is what ohm to buy or start with? i was told 15 to 20 to 25 but radio shack only carries bigger diff. numbers like 330 kohm and 30 ohm 1.5 1/4 resistors.... i was reading about this task online and it said to start off with 330 to 227 ohms.....i dont know anything about this stuff as this is my first time attempting this so any info. about this would be great.....thanks and hope to hear from you guys soon Eric

[IanSzgatti]

look up the resistance values you should see at 200F, take out the temp sender for your gauge, heat some water to 200F (12 degress off boiling), and then test the resistance against the spec.

the gauge itself COULD be defective, but be sure the temp sender is sending an accurate reading first.

if you do indeed need to add to the circuit, you'll take that resistance value and divide it by the temp... i.e;

345 ohms divided by 200F = 1.725 ohms per 1 degree F

then, to drop your gauge 20 degrees F,

1.725 ohms times 20= 35.5 ohms.

keep in mind these values are based on example...and im also not 100% that the resistance will move up in the increments I've laid out...not until I confirm it.... I have your year make and model so i'll look it up on mitchell... in the meantime I would make sure the temp sender is accurate, because I don't recall you confirming all that.

is your dash temp gauge digital or analouge??