Coolant noise inside cab, need help

Discussion in 'Engine Performance + Maintenance' started by Old Blue, Nov 30, 2017.

  1. RustyTruck

    RustyTruck Newbie

    Messages:
    6
    Likes Received:
    2
    Joined:
    Sep 23, 2017
    Location:
    Utah
    Huh...I've had that gurgling noise for over a year. Never really thought about it much. Figured it was my engine just gettin' a drink!

    I will have to try getting out some air.
     
  2. someotherguy

    someotherguy I'm Awesome

    Messages:
    3,337
    Likes Received:
    599
    Joined:
    Sep 28, 2013
    Location:
    Houston TX
    If you've had it that long, you have a leak.

    My last GMT400 did this for about a year, before one day I finally noticed a little trickle down the front of one of the heads. Intake gaskets were toast.

    Richard
     
  3. Old Blue

    Old Blue Newbie

    Messages:
    18
    Likes Received:
    2
    Joined:
    Jul 21, 2017
    Location:
    Iowa
    Update: I let the truck run for two hours yesterday with it jacked up, the radiator cap off, and the heat on high. I thought I had all the air purged out because it went for 10 minutes or so without purging anymore. Then today I drove it and still heard the coolant sloshing around. I still have heat, so the heater core should still be ok right? I'm just not sure what else to try.
     
  4. Old Blue

    Old Blue Newbie

    Messages:
    18
    Likes Received:
    2
    Joined:
    Jul 21, 2017
    Location:
    Iowa
    What did you remove to get the air out?
     
  5. 90halfton

    90halfton I'm Awesome

    Age:
    33
    Messages:
    625
    Likes Received:
    270
    Joined:
    May 23, 2015
    Location:
    Hutchinson, Ks.
    Water temp sensor. If I change out thermostat I just fill system til full to thermostat, then drop it in and bolt down housing. If I drain the system for anything I change the thermostat. It's like 10 bucks, why not. Not everybody agrees with that logic, to each their own.
     
    XJPhoenix likes this.
  6. Old Blue

    Old Blue Newbie

    Messages:
    18
    Likes Received:
    2
    Joined:
    Jul 21, 2017
    Location:
    Iowa
    Ok, thanks guys! Tomorrow is the first time I'll be able to work on it since I last wrote on here.
    90halfton, let me make sure I fully understand this. I need to drain the antifreeze down to just below the thermostat, right? Then I remove the temp sensor to let the air out, right? I'm planning on putting a new thermostat in also.
     
  7. 90halfton

    90halfton I'm Awesome

    Age:
    33
    Messages:
    625
    Likes Received:
    270
    Joined:
    May 23, 2015
    Location:
    Hutchinson, Ks.
     
  8. DerekTheGreat

    DerekTheGreat I'm Awesome

    Messages:
    225
    Likes Received:
    52
    Joined:
    May 23, 2016
    Location:
    Michigan
    Did you try goosing the throttle a bit while it was all jacked up? Maybe the extra flow might help push the air out. Mine still sloshes around too, less and less each week but I'll be flushing the system again in the spring so I'm not planning on doing anything about it until then.
     
  9. someotherguy

    someotherguy I'm Awesome

    Messages:
    3,337
    Likes Received:
    599
    Joined:
    Sep 28, 2013
    Location:
    Houston TX
    No big tricks needed to bleed air out of these trucks. There are some vehicles that are much more difficult because of the placement of the cap. GMT400's do not suffer this way. As I had said earlier park it on an incline, run it with the cap off, let it burp.

    If you're replacing your thermostat, drill a small hole in the flat area of it - like 3/32", just be sure you're getting it inboard of the gasket area, especially on the later style which uses the split o-ring style gasket that fits around the thermostat itself. Some thermostats have a little check valve built into them in this area; doesn't hurt to make your own bleed hole either way.

    I will maintain that if after reasonable efforts to bleed, you continue to have gurgling sounds out of your cooling system then you have some type of leak, somewhere, that must be addressed. Hose not sealing properly, leak at the notorious heater hose quick connect fitting, heater core leak, intake gasket leak, etc.

    Richard
     
  10. Old Blue

    Old Blue Newbie

    Messages:
    18
    Likes Received:
    2
    Joined:
    Jul 21, 2017
    Location:
    Iowa
    I just find it very odd (and coincidental) that it started making this noise after I replaced the radiator. It never did it before.
     

Share This Page