First i asked please. I looked through 20 pages and seen very similar but not exact problem as I am having. My cooling fan (the main one not the AC fan) does not come on while the car is running. However when I stop, put it in park and then turn the car off the stupid fan comes on. Pretty sure this is causing my overheating problem as I have replaced water pump, 180 deg thermostat, BIL replaced the fan and the temp sensor. So really running out of other reasons for this beast to be overheating. I am hoping this is something easy and some one a lot smarter and more familiar with these will know what is going on. Oh the car is a 91 Teg LS. 4 dr grandpa car. But hey better gas mileage then my fronty.
Thanks for the help in advance.
Search for problems involving Engine Oil Temp Switch… I’m not sure, but if it goes bad it may let the fan run when the car is turned off.
Also look into the ICU… That may also contribute to the problem.
These are just guesses. Research both of those to see if they can cause this problem.
I believe the BIL had that replaced too. I will have to check and thank you. As for the ICU I have already replaced that (dash lights, turn signals and all those didn’t work right when I got the car)
Basically a run down on this car. My wife’s Grandpa had this and had it PERFECT. He was an old school mechanical genius. He got sick and the last year of his life couldn’t fix the little things. After he passed MIL got the car, took to shady ass mechanics who caused more problems then fixed. She then gave car to the BIL. Same deal with him. After several towing bills he went and bought a new car. Behold JMZ gets a project vehicle to turn into a daily driver. Lets put it this way it always idled rough, no one ever took the time to look at the weathered and cracked timing belt and crankshaft gears to see if it was lined up and timed properly. Needless to say one tooth off on the back cam sprocket can make a difference. This thing has been one bug chase after another but I am getting close to having her good to go. Once I get the cooling issue fixed it is time to start in on the after market mods.
Here is a list of new/replaced items so far.
Distributor
Plugs and wires
Coil
Igniter
Fuel pump
Fuel filter
Temperature sensor
Temperature sending unit
Thermostat
Radiator fan motor
Front left cv axle
Front right cv axle
Two front tires
Fuel pressure regulator relay/(or fuel pump relay)?
Catalytic converter
Cap & Rotor
Exhaust pipe section above rear axle
All three belts
AC fan motor & shroud
Transmission fluid
Park break key release part
Wipers
Valve Cover Gasket w/ Gromets-1-19-13
Camshaft Cap - 1-19-13
Valve Cover/Head Ground -1-19-13
Spark Plugs (NGK Plat) -1-19-13
ICU -3-2013
Water Pump -4-27-13
Timing belt & tensioner -4-27-13
Thermostat - 180 deg -4-27-13
PCV valve - 4-20-13
Oil Change - 4-27-13
Thanks again for any and all assistance.
Bil?
Brother In Law - Mother In Law
Sounds like you have a bad ECT switch, the rad fan is turned on 3 ways, ECT switch, [when engine temp reaches 198 degrees F] when A/C is on, when ign. is off and EOT switch, [engine oil temperature] , when engine oil is “too” hot.
To test, with engine at running temp, gauge a 1/2 way or higher, unplug the ECT switch and jump the plug, if rad fan turns on, replace the ECT switch. 94
[QUOTE=fcm;2295806]Sounds like you have a bad ECT switch, the rad fan is turned on 3 ways, ECT switch, [when engine temp reaches 198 degrees F] when A/C is on, when ign. is off and EOT switch, [engine oil temperature] , when engine oil is “too” hot.
To test, with engine at running temp, gauge a 1/2 way or higher, unplug the ECT switch and jump the plug, if rad fan turns on, replace the ECT switch. 94[/QUOTE]
Thank you. Finally just taking a minute to get to this. Need to get my fronty (Frontier) into the body shop and then fixed as well.