I just recently found out my knock sensor issue, but i now cant figure out my fan issue. My coolant temp sensor in the water pump (not the head) was showing proper readings, 2700 ohms at 70ish degrees and i stuck the sensor in a bowl of hot water and it got up to 1000 ohms which is close to 115 degrees, which indicates that sensor works just fine. Im confused as to why my fans wont kick on when the car reaches 230-240, but they work just fine when i had an SES light for the knock sensor. Does anyone have some input??? Also, this may help someone pin point my issue, but i have a lopey kind of rough idle, but the car runs perfectly fine under any load at all. it pulls great and there is literally no other issue besides the fans and the idle. please help! also mods are Cold air intake, and Billet MSD opti.

 

Also, i forgot the car is a 94 firebird, M6.

 

Lil hazy but I believe the sender in head is strictly for idiot light on dash, you want to confirm the sensor in waterpump is functioning correctly.

 

My apologies i have no clue why i said in the head lol. That sensor is for the gauge cluster in the car, and to confirm, I looked at and checked the one in the waterpump.

 

Are you absolutely sure the sensor in the w/p is the correct one/part number?

 

yes I’m sure, I even went as far as checking the ohm readings that correlate with temperature with the shbox’s website. All is well with that sensor which is why I’m so confused. I’m also really confused as to why an idle would be lopey and rough but acceleration and driving normally is completely fine. Even revving sounds gfeat and there is no misfire stumble or anything. I’m hoping these two problems are correlated and easily solved!

 

Just because the sensor seems ok when you test it out of the car does not mean the readings are getting to the PCM. Use a scanner to observe temps and fan status.

 

where can I get a scanner for obd1 that can read temps and fan commands?

 

You have to buy cable to plug into a laptop. You can then DL software, which I think is free:

http://aldlcable.com/