temp creeps on interstate..

  • #1

    temp creeps on interstate..

    ok i searched and couldnt find a thread with a similar problem. i installed a taurs e fan on my z about two months ago. since i did the temp will not move once at normal, no matter how long you sit in traffic, etc. whenever i am cruising at 70mph or more on the interstate for over 20 mins or so, the temo will slowly creep past halfway, past the f on the gauge. it usually doesnt get warmer than that, though i do slow down a lil when it starts to happen. once im back around 60 or so it will move back down to normal. a friend told me that the large shroud on the fan may be causing the air pressure to change over certain speeds, and deflecting the air under the car. today i took the fan off and drilled SEVERAL 5/8" holes in the shroud, but it made no difference. the car has never overheated since this motor was in it, and it will only go to two-thirds or so on the gauge now, and only on the interstate after cruising for a lil while. keep in mind it is also 100 here everday, with index of 110. any ideas or should i be thinking head gasket?

    Foreign and Domestic Autocare
  • #2
    start with the simple stuff: radiator cap, pressure test system, radiator condition?. My guess is going to be fan clutch by what you described. The Z fan shrouds are fairly efficient and will *should* keep your cool under the hottest conditions if properly functioning. Also assess timing, can have an impact on temp. After all this checks out then start looking into the headgaskets, the pressure test should be an indicator.
  • #3
    Gregmatic wrote: start with the simple stuff: radiator cap, pressure test system, radiator condition?. My guess is going to be fan clutch by what you described. The Z fan shrouds are fairly efficient and will *should* keep your cool under the hottest conditions if properly functioning. Also assess timing, can have an impact on temp. After all this checks out then start looking into the headgaskets, the pressure test should be an indicator.

    How is it that your guess is the fan clutch when he has done an taurus electric fan conversion?

    Check the rotation of the elect fan to see if it is pulling air into the engine compartment or if it is pushing air toward front bumper.
    You may have the wires connected backwards.
    Should be pulling air into engine compartment.
  • #4
    that first sentence has a tendency to slip by sometimes :lol:
  • #5
    the fan is definielty going the right way, the radiator is the one that came in the car, so that could be my weak link…i will pressure test the system today, as well as do a leak down comp test. considering i own a shop that specializes in z cars, i better be able to get this one right..lol. radiator cap will be replaced today too, just to see

    Foreign and Domestic Autocare
  • #6
    I had this problem. The solution is to build a shroud/air duct before the radiator or have your fan come on high speed at a lower temp. I now run my taurus efan on low all the time and on high if the temp raises above the temp I set with my controller. It also comes on high with the ac.
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  • #7
    well did a coolant pressure test today, and it is slowly losing pressure somewheres, didnt see any leaks..so im figuring the awesome felpro head gasket i used didnt hold up..i guess i will be doing the vg33 waaaay sooner than i thought. i have serached, is there somewhere i can find a clear to do list for putting it in my car. i have a w series motor, still have to swap crank pulleys? i know i searched wrong or something, but themotor is goin on the stand tomorrow to get rebuilt this weekend. thanks for all the help. strange for overheating with cracked head gasket…no smoke at all, no coolant loss. doing leak down tomorrow and that will seal its fate.

    Foreign and Domestic Autocare
  • #8
    If its slowly overheating at highway speeds, I would suggest radiator. The fan is doing very little at 70mph. However at a constant 70mph, the coolant is moving very fast through the radiator and may not be dissipating enough heat during each pass.

    My car does the same thing, and I am currently awaiting a new radiator from radiatorswarehouse.com. I'll let you know if that alleviates the problem in the next few days.
    1988 NA2T 2+2 (currently using an 84T ECU)
  • #9
    yeah i am going to try and clean the coils on mine really well, i hope it works, i just cant believe i have a blown head gasket, due to not having symptoms…no coolant loss, white, smoke, etc. i ll let ya know too

    Foreign and Domestic Autocare
  • #10
    Just a quick follow-up.

    I installed the new radiator this morning and drove the car for about 30 minutes at 70mph. The temperature gauge never moved past a little below the halfway mark. I also spent about 20 minutes in stop-and-go traffic and had no issues. Not sure if my old radiator was the original or not.
    1988 NA2T 2+2 (currently using an 84T ECU)
  • #11
    Try to duplicate the same scenario… except turn the fan OFF at 70mph, the overheating may go away.

    I found that if the fan is not pushing/pulling enough air at highway speeds, temps will start to creep.

    Turn the fan off, go 70mph and see if it still over heats, may be something as simple as that.

    If that doesn't fix the problem, looks like you got everything else needed to do covered pretty well.
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