Engine overheating still after changing "ECT"

[azmattaz06]

Ok so a while back i wrote a post aobut my car overheating and when i mean overheating its going past the "N" if i don't have my AC on which is a stupid way to keep my car from overheating and i relly just wanna fix the problem.. As many of you said "Change the Engine Coolant Temperature Sensor" i did.. and honestly not a thing has changed.. But when i do a code test and the test it running thru all the sensors the fan does come on and also when it's really hot like a lil above the "N" i can hear the fan's coming on and off but it doesn't cool it down.. Anyone know what's going on? it's a 94 ATX.. they come on only when it's hot like close to going over the "N" and when i run the test it come's on.. i think one time i got codes 116 or 117 im not sure but would they have anything to do with what's going on? i mean it does come on but a bit too late and it doesn't even cool the engine down when it does come on i have to start driving before it goes down.. Sorry if im confusing but thank's for reading hope someone can help..

 

[Mr Anonymous]

Wow, I had to go back three months to find your original thread with this problem! I gather you never availed yourself of the help offered by the AZ SHO club at their meet?

Codes 116 and/or 117 would definitely have a lot to do with fan operation if the PCM isn't getting temperature data from the ECT sensor. It's not unusual for the wires to the ECT sensor connector to become damaged as that section of the harness can make for a very tight fit. It also wouldn't be impossible that you got a bad new ECT sensor out of the box. You're going to need a multimeter to determine a. if the harness is damaged/shorted and b. what the voltage output of the ECT is reading at various temps. The 116/117 codes really need to be corrected before going any further into the cooling system.

Also, another thing to double-check is when you read your codes and the fans cycle, you should be able to hear and feel two distinct phases of the fan cycle; first the fans engage at low speed, and then switch to high speed before shutting down. Make sure your fans properly run at both speeds at the beginning of the code reading routine. A loss of low speed can also result in the symptoms of the fan not seeming to come on until very late, but that still wouldn't cause the 116/117 codes.

 

[Storm-Chaser]

I'm curious - did you ever check/test the TEMP gauge?

Anything to actually verify the coolant temperature?

 

[cetroutt]

you know when i first got my SHO i was bothered by the fact that it had an aftermarket fan that was hard wired in. and the biggest question i got was why take it out to put a stock back in. i mulled this over for awhile and after some thought decided to leave it in. now i can turn my fan on and off whenever i want. actually i leave it running most of the time. it rarely goes up past the A unless i'm in a long drive-thru line and then it only gets up to the M. i know that fixing what ever is wrong is essential but a hard wired fan aftermarket fan might be something for you to look into later on.

 

[azmattaz06]

No i never checked the Temp Guage i wouldn't really know how to do that.. But i'll go check the wires to the ECT and make sure everything look's good if so im gonna have to find a multimeter to check that stuff out.. And no i never made it to the az sho club meet it was just WAY too far to drive.. And i know i can hard wire the fan to a switch but it bother's me to know something isn't working right and i'd really love to figure this out..

 

[itwonder]

One thing quick and easy to change. Install a new MOTORCRAFT radiator cap. Borrow a pressure tester from Autozone, Advance Auto, etc and check the cooling system for pressure leaks. It should hold about 13 PSI for at least 2 minutes. But you may not have a problem at all. Where does the needle run when you are driving at a constant speed? It should be around the middle or slightly above. At idle, the needle can go up into the N and it does not mean overheating as long as the fan is cycling. You may want to buy an inexpensive infrared thermometer so you can check the actual temperature . Harbor Freight has them.

 

[93MTXSHO_STUD]

my car goes to the N all the time when the car is sitting. Unless steam is boiling out of your radiator, im sure your fine. I've owned my car for 6 years now and never had any problems with the "overheating" problem. I've change the ECT and the other one wire sensor, never fixed the problem.

 

[naval-avi8or]

You say you changed out the ECT sensor. Just incase you don't know(and I haven't read your other thread) there are two sensors. One for the gage and one for the PCM. Which one did you replace.

 

[93MTXSHO_STUD]

There are two sensors. ECT which goes to the gage and ECT which goes to the EEC(cars microprocessor). Both sensors are on water outlet housing. Interestingly enough... I think the ECT that goes to the EEC is the same type that is on/near the radiator that reads the outside air environment temperature (and that sensor is off by a couple degrees at times). My moral of the story... if you change your oil regularly to avoid thermal breakdown and make sure your engines "real" temperature isn't too high, you should be in good shape. The only thing I havent changed in my car is the water pump. I don't know if all water pumps are created equally in terms of cooling efficiency, maybe it's the Texas hot summers.

 

[azmattaz06]

The one for the PCM.

 

[shoclown]

back in the 90s when i worked at ford the gauges were natrious for being bad after being pegged. they are easy to check. you feed resistance into the circut. have one resistor back for hot and one for cold