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  1. #1

    Default 86 N/A 3.8 overheating issue

    hey again, 86 is running stronger than ever since taking care of the fuel issue. But another thing has popped up.

    Took it to my high school football game last night, show it off and what not. No issues, afterwards I took it another 7 miles. No issues yet. 3 miles later and I noticed the coolant temp shoot up immediately. Pulled into a parking lot and let it cool down for a few minutes before making the trip home. Coolant system is stock other than a Black Magic fan taking over the clutch fan.

    Keep in mind this is the car that sat for just over 13 years, will be flushing the system, replacing thermostat, etc... Any other advice with keeping the 3.8 cool?
    Ray

    1986 Mustang "Frankenstang" '03 IRS 3.8 CFI
    1997 Crown Victoria, partially Grand Marquis

  2. #2
    FEP Super Member erratic50's Avatar
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    Back flush everything!

    And don’t use anything except a very reputable thermostat. Motorcraft is probably best.

    Have a radiator shop service the radiator and restore flow.

  3. #3

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    Everything he said above. I brought my 1986 Convertible 3.8 out of a 12 year slumber and didn't even mess with the radiator, i just bought a new one. I flushed the engine, new radiator, new hoses, new thermostat and have never had an issue with heating in Virginia summers crusing!

  4. #4

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    NEWS

    finally got all the parts to replace the water pump, thermostat, and all hoses. flushed out everything as well...

    still hot, the picture was taken after about a 8-ish mile drive.
    It really doesn't help that with the shorter gears due to the IRS swap, when i'm doing 45 mph I'm sitting at about 2500 rpm... took it back home after a fill up and it was sitting at the same level.

    Really thinking my only solution is to go ahead and drop the money on a bigger radiator since we'll have to do it anyway when we move forward with the SuperCoupe swap plan.


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    Ray

    1986 Mustang "Frankenstang" '03 IRS 3.8 CFI
    1997 Crown Victoria, partially Grand Marquis

  5. #5
    FEP Super Member gr79's Avatar
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    Could add an aftermarket mechanical temp gauge to see the water temp in real time.
    Adv or pep have Bosch 2" for less than 20.00 w/discount in stock right now. White face avail.

  6. #6

    Default

    The first thing you need to do is actually determine if the car is running hot. It very well could be that your temperature sending unit is failing, or more likely, your instrument panel voltage regulator is failing. My Capri does the same stuff all the time. Watch your oil and fuel gauges as I bet they become inaccurate the same time the temperature gauge does.
    86 Mercury Capri GS 2.3L
    11 Ford Ranger XL 2.3L
    10 Ford Focus SE 2.0L




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  7. #7
    FEP Super Member erratic50's Avatar
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    Check your grounds, especially the strap block to body. My 86GT would do the increasing gauge thing when the blower motor was on high. Shut off the heat or AC and the stupid thing would immediately drop to O of Normal.

    I agree - check it at the thermostat housing or put a gauge on it temporarily.

    Check for an application that uses the same neck that has a spot for a temp sensitive fan switch. Great place to bleed the air out of the system.

    My son’s 86GT is a complete antichrist about air locking air pockets for some reason. We have to bleed the air out at the temp sender.

    Good luck!
    Last edited by erratic50; 09-03-2018 at 09:24 AM.

  8. #8
    FEP Member
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    The gauge is reading correctly, but what we have to figure out is what the readings on the gauge correspond to in terms of actual temperature.

    After we had everything buttoned up yesterday I checked the temp at the radiator next to the upper hose inlet with a thermometer and saw 200 degrees with the needle on the “M”. It never got hotter than that sitting in the driveway and that’s where I set the electric fan to come on.

    What is supposed to be the normal operating temperature for these engines? In my head, 200 is about as hot as I want to get, but some reading has told me that 220-230 is ok. If that’s the case we might be concerned about nothing.


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  9. #9
    FEP Member
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    Default

    The gauge is reading correctly, but what we have to figure out is what the readings on the gauge correspond to in terms of actual temperature.

    After we had everything buttoned up yesterday I checked the temp at the radiator next to the upper hose inlet with a thermometer and saw 200 degrees with the needle on the “M”. It never got hotter than that sitting in the driveway and that’s where I set the electric fan to come on.

    What is supposed to be the normal operating temperature for these engines? In my head, 200 is about as hot as I want to get, but some reading has told me that 220-230 is ok. If that’s the case we might be concerned about nothing.


    Sent from my iPhone using Tapatalk

  10. #10

    Default

    quick update.

    decided to drop money on a new aluminum radiator, she's running cooler than ever now.


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    Ray

    1986 Mustang "Frankenstang" '03 IRS 3.8 CFI
    1997 Crown Victoria, partially Grand Marquis

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