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14 Temp Spike

Discussion in '3rd Gen - 2007 - 2017' started by Joe Public, Jun 30, 2020.

  1. Joe Public

    Joe Public Member

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    I have no earthly idea how to search for this particular issue, so please forgive me if this has been talked about before.

    I just recently bought a 2014 Expy EL 5.4l with approximately 90k miles on it. It’s in relatively good condition all things considered.

    Issue: Yesterday I was sitting in a drive through on a rather hot day (NE FL inland). I noticed my radiator fans were at full speed, which I thought was regular considering the hot day. While waiting for food, I watched the temp gauge slowly climb - we got the food and started to drive, but then the temp gauge red lined and the display on the instrument panel showed the temp warning. No CEL at all.

    I then got on the road and drove, thinking the car would cool down because air is now moving freely. The temp gauge went back down to normal (mid way) and it didn’t rise again through the rest of the hot day. I don’t remember if the fans were still on full blast as I didn’t realize this was going to be a reoccurring issue.

    Today while driving into town, the temp gauge did the same thing - but this time it was a bit quicker in rising. The fans kicked on only a few minutes after driving (slow speed to get out of the neighborhood, then up to 65-70mph, back down to 35mph in the city). The temp gauge red lined, the warning popped up, but this time we had already reached our destination and the car was turned off.

    We made another short trip and the temp gauge went from normal to rising while at idle. The fans were on again at full blast. I turned the car off, then back on when we left. While driving at highway speeds, the temp gauge went up again, but this time I turned the heat on (up to 80 on the driver side). The temp gauge normalized and was fine, but the heat was barely warm, not 80.

    I haven’t checked the coolant level as I’m currently typing this in bed, but I will tomorrow when I get a chance.

    When the temp goes up, the AC gets really cold. I haven’t noticed a performance difference in the vehicle. The temp gauge seems to red line, then go back down to normal and stay there for the remainder of the trip. No CEL yet.

    An internet search with my limited knowledge/terminology only turns up F150 overheating issues. Any ideas or perhaps links to a previous post about this issue?

    Thank you in advance!
     
  2. 07navi

    07navi Full Access Members

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    It isn't getting that hot because it didn't go into limp mode plus when the outside temp goes up the AC gets warmer too, not colder. Drain a little water out of the rad and see how hot it is.
     
  3. Joe Public

    Joe Public Member

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    Thanks for the response! I’ll look into that once I can check coolant levels.

    Let me say this: perhaps there’s no correlation between the engine temp spiking and the AC getting colder - this all happened today after a cold start on a hot day; the AC could’ve just gotten down to normal when I noticed the fans going nuts.
     
  4. 07navi

    07navi Full Access Members

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    The fans do pull more air across the condenser when they speed up but it doesn't take much airflow to cool the ac down. Maybe your fans are getting false signals. When you think the engine is really hot drain a quart of water and put a thermometer in it or just feel the sides of the container or run your hand across the stream. It might just seem like it's getting hot. Check the OBD II with a scanner for codes also.
     
    Last edited: Jun 30, 2020
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  5. Boostedbus

    Boostedbus Full Access Members

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    As long as the coolant level is correct, I’d suspect sticking thermostat. The T-stat can be sticking closed and making the engine hot and the radiator cold which in turn would make the A/C colder because the radiator isn’t heating up the condenser.
     
    Last edited: Jul 1, 2020 at 7:01 AM
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  6. Joe Public

    Joe Public Member

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    The coolant level was low. I filled it up to the line; we’ll see what happens if the wife drives it today.

    Thanks again for everyone’s replies!
     
  7. Boostedbus

    Boostedbus Full Access Members

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    How low?
     
  8. ExplorerTom

    ExplorerTom Full Access Members

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    I’ve noticed the same with mine. I changed out my thermostat and flushed the radiator too. Still does it- although mine doesn’t do it as bad as yours. My 2014 will get up to 220 while idling for an extended period of time (drive thru or whatever) but cools back down to 190 once I get moving. The factory needle doesn’t register any movement during this. I read it through an UltraGauge.
     
  9. Joe Public

    Joe Public Member

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    It was 3AM when I checked using the light on my phone, but I’d say it was low enough to not see it through the side of the reservoir. I could only see the fluid in it when I opened the top.

    I’m certainly hoping a new thermostat will help if the problem persists now.

    No new update as of now. I will update if/when the vehicle gets driven.

    Thanks again, everyone!
     
  10. Don Hall

    Don Hall Full Access Members

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    Cooling is a simple equation. All that is needed is coolant flow, and air flow.
    Stop one, or both, and you will experience overheating.

    Your truck uses a closed cooling system. As the coolant heats, it expands, and
    travels to the overflow bottle. When it cools, it reverses flow via a siphon back to the radiator. Outside air does not enter the 'closed' system. If it does, no siphon will occur, and the coolant level will keep getting lower.

    How air enters the cooling system.....deformed cap gasket, loose/damaged connections, any unit failure/break in the system.

    As mentioned, a properly working t-stat is important. A t-stat that only opens
    partially, or not at all, will cause overheating. To check a t-stat, remove it, and
    place it in boiling water to determine if it opens, or not.

    Of course, the coolant must always be at the 'full' level. If continued filling is required, you need to check for leaks. A simple pressure test using a pump connected to the rad cap opening will detect any leaks. To check the block, the
    t-stat must be removed.

    Ensure the fans activate at the proper temps, check a maintenance manual for fan activation temps (I didn't see any temp numbers in my Owners Manual).
     
    Last edited: Jul 1, 2020 at 2:56 PM
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