Won't stop overheating

Discussion in 'Technical' started by Anti, Apr 3, 2012.

  1. Anti

    Anti 14.7 x 14.7 = 44.1

    my z32 has:

    - new water pump
    - new thermostat (tested before installation)
    - every single coolant hose replaced, no leaks
    - new coolant
    - new 56mm radiator
    - new radiator cap

    - tested and 100% viscous clutch fan
    - heater core is bypassed

    - FMIC

    WHY WON'T STOP ****ING OVERHEATING

    I've bled the radiator (with the front end up) 8 ****ing times

    On idle it won't go past 81*

    At low speeds through traffic etc it sits between 90 and 94, far too high for my liking

    On the freeway it just goes up and up and up until I pull over. It'll happily cool itself on idle from 100*. When I get going again, it'll just really really slowly climb. Today while cruising at 110 it was on 96* for 10 minutes before ticking over to 97*, and so on...

    the ENTIRE COOLING SYSTEM IS NEW. What the **** is wrong with it?

    -A
     
  2. brisz

    brisz Well-Known Member

    What lower hose do you have ?
     
  3. Anti

    Anti 14.7 x 14.7 = 44.1

    upper and lower hose are silicon units from Marcus @ car craze, the rad's his too
     
  4. SRB-2NV

    SRB-2NV #TEAMROB

    You have any ducting to the radiator?
     
  5. Anti

    Anti 14.7 x 14.7 = 44.1

    OEM splash guards are in place and I have a full width radiator air guide (which admittedly wasn't fitted today)
     
  6. brisz

    brisz Well-Known Member

    EDIT: Is your front lower spash gaurd in place ?

    The lower hose may be collapsing.

    Also where are you getting these temperature readings from, consult ?

    The car is definitely getting hot ?
     
    Last edited: Apr 3, 2012
  7. SRB-2NV

    SRB-2NV #TEAMROB

    I mean from the front of the car, the FMIC would block a fair bit of airflow to the rad i would think?
     
  8. a2zed

    a2zed Guest

    How did you test the fan?

    What brand t/stat?
     
  9. Anti

    Anti 14.7 x 14.7 = 44.1

    I've been underneath the car and it's always been "plump"
    Yes
    No unfortunately, but I have the engine one behind it. I'm planning to make one up when I have the time.
    Plastic ruler test as per tech section
    OEM
     
  10. brisz

    brisz Well-Known Member

    No front lower splash gaurd between the front of the bar and radiator makes it hard, with a FMIC the radiator would probably be seeing less than 50% of what it normally would.
     
  11. planetrobbi

    planetrobbi planetrobbi

    Might be a long shot but faulty earths or earth cables can do this . My old Rx7 after a clutch change would shoot up on the temp dial as the gearbox earth cable was stuffed, for good measure I put on about three new earth cables and it was fixed - long shot I know though.
     
  12. a2zed

    a2zed Guest

    Plastic ruler test is useless. Get the car to operating temp via a short drive. With engine running, open bonnet and watch the fan, have some one switch off the ignition. If the fan does more than 2 or 3 revolutions after the engine has stopped, it is not working very well.
     
  13. Anti

    Anti 14.7 x 14.7 = 44.1

    is that really enough to do this though? I know two people with FMIC's and after market front bars with OEM radiators that don't overheat
     
  14. Anti

    Anti 14.7 x 14.7 = 44.1

    It cuts off very promptly after engine off IIRC

    I should add that car happily drove 1500 kilometers to me before I changed the radiator and upper and lower hoses. same clutch fan, thermo, water pump, etc...
     
  15. mijake

    mijake Member

    My money is on viscous fan. Sounds exactly the same symptoms as when my clutch fan died.
     
  16. Anti

    Anti 14.7 x 14.7 = 44.1

    I was under the hood today while it was running at ~90* and it was fanning like a mother****er...
     
  17. a2zed

    a2zed Guest

    If it was fine before, and now overheats, it seems the rad or hoses would be the cause. Knowing this info, I agree with brisz, change the bottom hose to a known peice.
     
  18. Anti

    Anti 14.7 x 14.7 = 44.1

    I have the old OEM hose that I took off, can I simply check to see if the lower hose is folding or is it possible it could be happening only at speed?
     
  19. brisz

    brisz Well-Known Member

    Well the FMIC is going to heat what air it passes and deflect some underneath, and without the splash guard some air will take the path of least resistance under the radiator, yep there is a fair loss in cooling.

    It may not be the only cause.
     
  20. brisz

    brisz Well-Known Member

    Yes put the OEM hose back on and see what happens.
     

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