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.

Glow plug light blinks once after truck is started

Discussion in '1982-Present GM Diesel' started by AzzKicker, Oct 10, 2002.

  1. AzzKicker

    AzzKicker 1/2 ton status

    Joined:
    Jul 28, 2002
    Posts:
    265
    Likes Received:
    0
    Location:
    Edinburg, Tx
    Ok, I turn on pickup, GP light comes on and turns off, so I turn on truck. Once truck is on, glow plug light blinks after its on. This has me worried because in case one day it decides to stay on. What can cause this.
     
  2. Can Can

    Can Can Pusher Man Staff Member Super Moderator

    Joined:
    Feb 17, 2000
    Posts:
    15,552
    Likes Received:
    136
    Location:
    Cochrane, Alberta, Canada
    There's nothing to worry about. 6.2s do this as the engine warms up. In the winter my GPs will cycle up to 10 times after the engine fires.......

    I would be more worried if it DIDN'T happen.
     
  3. AzzKicker

    AzzKicker 1/2 ton status

    Joined:
    Jul 28, 2002
    Posts:
    265
    Likes Received:
    0
    Location:
    Edinburg, Tx
    Cool. I wont worry then now that I know its normal.
     
  4. arveetek

    arveetek 1/2 ton status

    Joined:
    Mar 1, 2002
    Posts:
    722
    Likes Received:
    0
    Location:
    Granby, MIssouri, USA
    It's called after-glow. It's supposed to aid the motor in running smoothly until it warms up some. It's normal for the plugs to cycle on and off for a about a minute or so. If it keeps cyclying on and off all the time, then that's another problem.

    Casey
     
  5. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    I could be wromg on this, last time I read abot glow plugs was a couple of uears ago, but I think this system started with 85 model year. Is your's 85 or up?
     
  6. arveetek

    arveetek 1/2 ton status

    Joined:
    Mar 1, 2002
    Posts:
    722
    Likes Received:
    0
    Location:
    Granby, MIssouri, USA
    All glow plug systems use after-glow. The '82-84 used a crappy thermo controller, and the 85+ used an electronic controller. Both cycled the plugs after starting, although I think the earlier systems cylced much more than the later ones.

    Casey
     
  7. AzzKicker

    AzzKicker 1/2 ton status

    Joined:
    Jul 28, 2002
    Posts:
    265
    Likes Received:
    0
    Location:
    Edinburg, Tx
    Ya mines an 85 and it really only cycles once after. And thats about it. It really only does the first time I turn it on for the day. I'm still fixing the truck up so I havent really been driving it too much. I usually just turn it on and will drive to the store etc. And say after I turn it back on at the store it wont do it. Usually just after it gets cold. /forums/images/graemlins/truck.gif
     
  8. BigBluOx

    BigBluOx 1/2 ton status

    Joined:
    Aug 30, 2001
    Posts:
    301
    Likes Received:
    0
    Location:
    Auburn, WA, USA
    Mine will intermittently cycle long after the truck has reached 'operating temperature'. Glow plug cycling will be normal to start it, and it will do the 'after-glow' thing, and they will stop cycling - but sometimes, they will begin to cycle again before I get to work (up to 10 minutes after they initially stopped cycling). Is this an indication of a failing temperature device in the system? /forums/images/graemlins/1zhelp.gif I've read somewhere that the '84 glow controller 'looks' at both temperature and voltage level to determine when to stop cycling (alternator output appears normal). At this point, after the truck warms up and the glow plugs stop cycling, I disconnect the glow relay to keep them from cycling as I'm driving down the road (they have 'stuck' on before while driving /forums/images/graemlins/frown.gif ). Am I in the ball-park on my diagnosis?

    Thanks,
    Jon /forums/images/graemlins/burb.gif
     

Share This Page