Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

Running Hot, Gauge, Wire, Sending Unit??? Which is it?

Discussion in 'The Garage' started by PsRumors, Dec 18, 2006.

  1. PsRumors

    PsRumors 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    626
    Likes Received:
    0
    Location:
    Cartersville, GA
    Here is what I have '85 K20 Burb with a newly transplanted 454, got it running today.

    Temp Gauge is showing at the line between 210 & 260. Replaced the sending unit and got the same thing. The gauge does rise and fall but is just high.

    If my notes I have are correct the following ohm values correspond to the temp.

    210* - 185 ohms
    160* - 450
    100* - 1800

    I put the ohm meter on the sending unit and am reading between 220 and 240 ohms. I am running a 180* thermostat.

    Anyone with experience?

    I want to use the stock gauges cuz that is what I like. It was working prior to the engine change.

    Thoughts?
     
  2. mr.smartass

    mr.smartass 1 ton status Premium Member

    Joined:
    Aug 10, 2004
    Posts:
    10,860
    Likes Received:
    4
    Location:
    Hattiesburg, MS
    Umm I don't know maybe the motor is running hot... It's the only thing you changed right? :rolleyes: Just something to look into.
     
  3. PsRumors

    PsRumors 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    626
    Likes Received:
    0
    Location:
    Cartersville, GA
    Yup....a possibility but I dont think it is. If you look at the ohms I pulled off the sensor it doesn't appear too. Do you have any experience with the ohms value of the sending unit? I am wondering if my values are correct.

    It doesn't seem the engine is running hot. The coolant temp in the radiator about 10" below the filler neck is at 170*.
     
  4. mr.smartass

    mr.smartass 1 ton status Premium Member

    Joined:
    Aug 10, 2004
    Posts:
    10,860
    Likes Received:
    4
    Location:
    Hattiesburg, MS
    nope no experience with the ohms... What motor came stock in the burb? Is the sending unit the same as the one that came with the stock burb?
     
  5. PsRumors

    PsRumors 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    626
    Likes Received:
    0
    Location:
    Cartersville, GA
    It was a 350. I haven't checked to see if the sending units were the same....good catch.
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    I believe the reistance should be 0-90 ohms, (full sweep of gauge) make sure you've got good contacts, and good wires on your tester.
     
  7. BlaKK54Speed

    BlaKK54Speed 1/2 ton status

    Joined:
    Dec 14, 2006
    Posts:
    242
    Likes Received:
    0
    Location:
    Omaha, NE
    its all in the "ohmage" make sure the sending unit is designed for that kind of gauge
     
  8. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,583
    Likes Received:
    945
    Location:
    Massachussetts
    one thought..

    Did ya swap in a big block radiator to go with the 454??...a small block one may not be big enough,and will make it run hot!...:crazy:
     
  9. PsRumors

    PsRumors 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    626
    Likes Received:
    0
    Location:
    Cartersville, GA
    I did swap in a new radiator but all of them have the same part #.

    I do believe though it is the sending unit. Just haven't had a chance to work on it.
     
  10. 3 on the tree

    3 on the tree 1/2 ton status

    Joined:
    Oct 16, 2004
    Posts:
    3,970
    Likes Received:
    0
    Location:
    gunnison colorado
    Two ideas;

    Ground the sending unit wire, with the gauges on. The gauge should read full sweep right, at least every one I've ever tried has.

    Are you sure you got ALL the air bubbles out of the cooling system? A large air bubble will do all kinds of weird things.:doah:
     
  11. PsRumors

    PsRumors 1/2 ton status

    Joined:
    Nov 11, 2006
    Posts:
    626
    Likes Received:
    0
    Location:
    Cartersville, GA
    Grounded it sweeps full hot.

    I believe I have a sensor issue. I just haven't had any more time to work on it.
     

Share This Page