Engine Too Hot, A/C Turned Off

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by Kris34, Jan 24, 2014.

  1. Kris34

    Kris34 New Member

    Started truck this morning with remote starter and it ran for about 10 minutes. Went out to clear the snow off and sounded like it was idling fine. Put key in and turned on and truck went into low power mode and the message "Engine Too Hot, A/C Turned Off", came up on the dash. I turned the truck off and tried to restart and same thing. In fact it barely starts. Left it all day and went walked to work. Just got home and tried it again. It started but you can tell it's in low power mode. No SES light just the message on the dash. Has anyone seen this?

    A few side notes. Truck HAD the GM thermostat plug. Circuit would not open to allow power to block heater so I cut it off and just put a normal cord end on. Been that way for about 3 weeks now with no issue. Just thought I would mention that.
  2. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    If you cut the 110 volt cord for the block heater, it should not impact the trucks cooling system.

    However, you could have a problem with the cooling system.

    Truck info and your location info is a big help, it saves guessing.

    So, I'm guessing............................................your in a very cold location, you have not checked the specific gravity of the coolant....................................your coolant froze
  3. Kris34

    Kris34 New Member

    Sorry about that. I live in northwestern Ontario. I was about -30 with the wind yesterday. I plugged the truck in when I got home from work at 5:00. Warmed up to about -15 in the morning when I went to work in the morning that's when I tried to start it and this issue started. I did some reading and some guys said they had to replace their t-stat. Another guy said he lifted the battery cable for 10 minutes and issue gone. Not sure what to do

    2007 New body style GMC Sierra 1500 Vortec Max
  4. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Well, hard to tell from here (welcome, by the way, I'm in New Brunswick).

    Under those conditions, there is only one way for that message to appear (assuming the sensors are working correctly) and that would be for the cooling system to have a blockage.

    Normally, only two ways for it to be blocked........a bad thermostat, or.........ice in the block.
  5. Kris34

    Kris34 New Member

    We've been dealing with -30 to -40 with wind chill temps for weeks and no troubles running so I don't think, now I'm no expert or mechanic, that it would be a frozen block. T-stat maybe?
  6. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    I agree, more likely the t-stat.

    Wind chill only impacts people and animals. If the coolant is no longer able to handle cold temps, you could have a frozen block.

    You have a coolant overflow tank that is made of see through plastic. Is the coolant in there liquid, or slushie?
  7. Kris34

    Kris34 New Member

    Haven't checked yet. I will reply back in a bit after I check

    - - - Updated - - -

    So I got out to check. coolant is in liquid state and is just slightly below the full cold level. Does it sound like the t-stat. What about the idea of pulling the battery terminal to clear it?
  8. j cat

    j cat Epic Member 5+ Years 1000 Posts

    the actual air temp is the temp that the coolant is effected. wind chill is only for living organisms.

    with the extreme cold the radiator can freeze. then you get the bad thermostat effect. I would get a dexcool tester and make sure it is @-40deg f.....

    also what is the temp of the air coming out of the heater ? if the temp is not hot and the sensor says over temp good chance it is frozen or sensor is bad/connections etc..
  9. Kris34

    Kris34 New Member

    Just an update. I pulled the battery cable to clear the error just to see what happened. Error gone. Started truck and let warm up a bit as it has sat for a few days in the cold. Truck came up to temp so went for a ride around the block. About a 2 or 3 minute drive and temp gauge was just under 100 degrees. Hopefully just a stuck sensor. We had one day that it warmed up and then went into a deep freeze again
  10. RayVoy

    RayVoy Epic Member 5+ Years 5000 Posts

    Hopefully you will also take the advice of a couple of members and have the anti-freeze of the coolant tested.

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