1. We are working on the forum's attachment system. Attachments and avatars will be intermittently affected over the next 24 hours.
    Dismiss Notice

1994 Chevy full size pickup with temp gauge issue

Discussion in 'Technical Discussion' started by zamimj222, Jan 15, 2016.

  1. zamimj222

    zamimj222 Well-Known Member

    Messages:
    51
    Likes Received:
    0
    I am looking for some help. I have a 1994 Chevy K3500 Cheyenne with a 5.7L. approx 64,000 miles. Mileage is correct. It used to be a plow truck at work. Problem I am having is temp gauge on the dash reads approx 150 degrees after being warmed up and when I plug in the OBD1 tool it says the engine is around 195 degrees. I replaced the stat as I had issues getting the engine to warm up like it should. Found the stat was stuck open. Replaced the sensor between #1 and #3 cylinders after grounding the wire off the sensor and the temp gauge pegged. Looking for some help to fix this. The old sensor was reading low too. Guess I am down to wiring issue.....
     
  2. Mooseman

    Mooseman Moderator

    Messages:
    10,517
    Likes Received:
    5,038
    I would imagine it would be. Look on the internet for what resistances that should translate to what temperature. Could be the gauge itself.
     
  3. MRRSM

    MRRSM Gold Supporter

    Messages:
    1,613
    Likes Received:
    730
    If you can Google some images of the Coolant Sensor Locations... the 1994 GM 1500 5.7L Engine appears to have TWO of them... one on the Driver's Side Cylinder Head and one mounted close to the Intake Manifold/Coolant Hose Elbow area on the front Passenger Side of the motor. It seems possible that if they have Two Different Part Numbers and Behaviors that could be threaded in at the WRONG locations and thereby... provide incorrect read-outs on the Dash Gauge.
     
    Last edited: Jan 16, 2016
  4. zamimj222

    zamimj222 Well-Known Member

    Messages:
    51
    Likes Received:
    0
    I have been searching the internet for 3 days before posting. For some reason this seems to be a mystery of why this isn't posted anywhere. Gauge seems to work accurately. If I install a 46 ohm resistor, it goes right to 260. But then again, I am kind of guessing that the resistance matches up with tthe temperature...
     
  5. zamimj222

    zamimj222 Well-Known Member

    Messages:
    51
    Likes Received:
    0
    When I went to the parts store, they do have both sensors. The one by the thermostat housing is used by the computer in the truck and the scan tool. The one between cylinders 1 & 3 goes to the gauge. I replaced the correct one. Just wanted a reliable gauge to make sure I don't over heat or something else is going on. I'll keep searching. Maybe I will install a mechanical gauge and see if that is better.
     
  6. Mooseman

    Mooseman Moderator

    Messages:
    10,517
    Likes Received:
    5,038
    Had a look in GM SI and it has nothing for 1994 but did find this for 1996:

    So your check seems to be close.

    Here's there chart for the 02 TB. Seems to be the same for 266F (7 ohms difference is negligible).
     

    Attached Files:

Share This Page