intermittent overheating

Discussion in 'Engine & Drivetrain' started by dlnelsonroca, Dec 18, 2016.

  1. dlnelsonroca

    dlnelsonroca Member

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    Hello! I have what's probably a simple problem, but I need your expertise to really know what to do. Here's my issue:
    I've recently had the engine rebuilt because of a bad overheat. All original parts and the inexpensive labor here in southern Mexico. I am having a catalytic converter brought here in a few weeks because we couldn't find the right one here. So the mechanic here put in something else in the meantime. The code came up a few days later of P0420 catalyst system efficiency. Since then I've gotten two other codes, P0013 and P0014. I mention these jsut to give all the background possible, although they're not my chief question right now.
    A few days ago the car began to overheat. I had the AC on, but turning it off didn't change anything. I drove home, about a half hour, and as long as I was going quickly the temperature stayed normal, but as soon as I slowed down for a speed bump or went slower than 50 mph, the temp gauge rose quickly. I ended up turning it off about a half mile from my house, and getting it later after it cooled off.
    The water pump doesn't wiggle, and so I assume that it's okay. The coolant looks good as well, and appears to be half coolant, half water, although I can't tell for sure. It's bright green.
    Now the mystery to me is that since then I've driven it all around my little town, letting the heat go to nromal temperature, and with the AC on, and no overheating. I haven't dared to drive anywhere farther for fear of overheating. I almost wished it would overheat again so I could check to see if the fan was working, but it is working in town.
    Is this the thermostat beginning to fail? Or something else. I need to k now so I can order a new one from the States with someone who's coming here in two weeks.
    Thanks!
     
  2. Wooluf1952

    Wooluf1952 Well-Known Member

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    You should've heard the fan if the engine was overheating and the fan was working. It would've sounded like a jet engine.
     
  3. AWD V8

    AWD V8 Well-Known Member

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    A bad thermostat is the first thing I think of when operating temp is inconsistent. Only use an OEM thermostat.

    The above is assuming that you do not have air trapped in the cooling system.
     
  4. gmcman

    gmcman Well-Known Member

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    What temps are you seeing when it's overheating? Are you sure the coolant is topped off? Did you mix green antifreeze with the orange dexcool?

    A remote possibility is a bad head gasket introducing bubbles into the cooling system but hopefully that's not the case.
     
  5. Mooseman

    Mooseman Moderator

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  6. dlnelsonroca

    dlnelsonroca Member

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    Thanks! I did the check on the fan at operating temperature. I could stop it with a rag, and once stopped it was easy to hold stopped. It looked almost exactly like the video posted above. Does that mean it's good or it's bad?
    The motor was all apart, so the only coolant in it was new and green.
    I don't recall the fan sounding like a jet engine at any point.
    Right now when I tested the fan and then turned off the motor, I heard a sound from the coolant reservoir like a popping bubble about every two seconds, not boiling, just a pop, and the water in the reservoir would move a little bit.
    I haven't taken the car outside of my village since the overheat, and idling in town hasn't overheated it again.
    Any way to figure out what's up with these new clues?

    Also a slight hissing from the same general area while it was popping.
     
    Last edited by a moderator: Dec 19, 2016
  7. Mooseman

    Mooseman Moderator

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    That would mean the fan clutch has failed and probably the reason for the overheat. Our favourite replacement is Hayden. Dorman are hit or miss like most of anything from them electrical.

    The popping is probably the cap releasing pressure to the reservoir tank as it gets hot. Normal and would become worse as it overheats.
     
  8. dlnelsonroca

    dlnelsonroca Member

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    That's good to know! I've just ordered a Hayden fan clutch from Rockauto. It will be nice to drive on the road again without worrying about overheating!
     
  9. MRRSM

    MRRSM Gold Supporter

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    Matt likes this.
  10. gmcman

    gmcman Well-Known Member

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    I'm not doubting that the fan may be bad, but if there was green coolant....are you sure all the orange dexcool was flushed out?

    I'm pretty sure the green doesn't mix well with the orange, not 100% certain if that can cause it to gel up.

    If you disconnect the coolant temp sensor, the fan should lock up and fully engage as a safety default....does it?
     
    Matt likes this.
  11. Matt

    Matt Silver Supporter

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    That's exactly what it does. If you go to green coolant, you need to completely flush the block, heater core etc to make sure there's no residual Dexcool.
     
  12. xavierny25

    xavierny25 Platinum Supporter

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    I'm a +1 on you can't mix the Dexcool and the green stuff. Although my issue was with my 06 RR sport at a local jiffy lube they add the green coolant to top off and the reserve rank expolded about 20 miles later. Of course the jiffy lube place covered the repair and a rental for 2 days.
     

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