News

400i Coolant loss.

Discussion in 'Technical Q&A' started by timthetooth, Feb 23, 2004.

  1. timthetooth

    timthetooth Rookie

    Dec 18, 2003
    33
    Hi Guys. I have been trying to solve this problem for over a year now!
    Symptoms are a loss of about 2 pints of coolant after a long drive. I know when it has happened as the driver side heater blows cold even when engine is hot. Car gets hot in traffic and coolant seems to exit via the expansion tank over-flow.
    My theorys include:
    1. Blown head gasket. They where both replaced 18 months ago, but have not had the head bolts retorqued, is this needed? Job was done by my brother-in-law and I and both heads were skimmed and crack tested.
    2. Leak from a pipe or join in cooling circuit. I found a leak from a heater valve pipe recently while I was pressurising the system with a pump, cold. At 13lb there was no leak into the cylinders. This changed one of the symptoms which was the expansion tank now empted as it should as the engine cooled down after shutdown.
    3. Air in system. I think these cars are fairly easy to bleed. I have even lifted the front of the car and think I am achieving a good bleed.
    Has anyone had a similar problem with this type of Ferrari, I would be interested in any ideas anyone has.
     
  2. To remove this ad click here.

  3. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    There are several things to do / check, I would :-

    Pressure test the cooling system, leave overnight and look carefully for any external leaks - if you are sure there aren't any external leaks make sure the radiator cap is holding pressure (13-14lbs)

    I would also look carefully at thy two heater matrixes, but normally if they leak you will smell anti-freeze inside the car.

    Have you done a cylinder leakage test ?

    In the past I have overhauled many V12 engines and have found a cracked cylinder liner, is there any evidence of coolant in the oil system.

    Finally, yes you should re-torque the cylinder heads.


    MW
     
  4. timthetooth

    timthetooth Rookie

    Dec 18, 2003
    33
    Hi MW, thank you for your advice.
    I will check possible external leaks first, the expansion tank cap is new and tested, it is functioning correctly. The heater matrixes are a possible source of leaks, and I will examine them.
    There is no evidence of coolant contamination in the oil, is it possible the pressure of combustion is forcing gas into the cooling system at high revs?
     
  5. Ferrari_tech

    Ferrari_tech Formula 3

    Jul 28, 2003
    1,527
    UK
    Full Name:
    Malcolm W
    It is possible that there are combustable gasses being forced into the cooling system via the head gaskets - there is a simple "sniffing" device which fits onto the radiator neck in place of the rad cap and will detect if there are any gasses present in the cooling system.

    Snap-on make one, but you should be able to purchase one from any decent automotive tool supplier.



    MW
     

Share This Page