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328 mystery oil leak

Discussion in 'Technical Q&A' started by speeder37, Feb 12, 2004.

  1. speeder37

    speeder37 Karting

    Nov 18, 2003
    93
    Chicago
    Full Name:
    Matt
    I will pose a baffling question.
    I have a 328GTS that needed a clutch. I had an IFS do the job. I got the car back and realized an oil leak coming out of the bellhousing. The shop took the car back ansd replaced all o'rings. In addition they removed the flywheel and replaced the rear main. The car leaked again after prolonged highway running. They did the entire process over again. Ran the car for an hour, no leak. I drove the car on the highway for 100 miles. Same leak began to appear. The shop is now investigating pressure buildup in the engine causing oil to be forced past the main. This shop incidentally performed the entire 30k service at the same time. The car has 20k miles. Has never been a leaker.
    Any thoughts on what they are missing?
     
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  3. TCM

    TCM Formula Junior

    Nov 10, 2003
    552
    Tyngsborough, MA
    Well, from what you describe I have a feeling the leak is not from the bell housing. Since it does not appear there when not moving, I bet you have a leak futher up in the engine that is getting blown back onto the bellhousing when driving resulting in a drip from the bellhousing. I am not that familiar with the 328 setup, but this is common in many cars. You best bet is so start looking for oil leaks on the ground when the car is parked or try to trace the path of the oil from the bellhousing.
     
  4. KurtK328

    KurtK328 Formula Junior

    Mar 6, 2001
    347
    Villeneuve-Loubet, France
    Full Name:
    Kurt Kjelgaard
    What is your indicated oilpressure during the highway runs?
     
  5. speeder37

    speeder37 Karting

    Nov 18, 2003
    93
    Chicago
    Full Name:
    Matt
    Oil pressure is normal at 65 to 75 lbs.
     
  6. Diablo

    Diablo Formula Junior

    Since the major service was done, i would say that all of the gaskets are good.

    The trick is the rear main. Is it a rotational seal they installed??

    I have seen a guy rip out his TR clutch 3 times to find out that the rear main seal he put in was the wrong rotation. Instead of sealing, it would wick out the oil.

    Also,double check the O-ring seals that attach the bellhousing to the trans.
    Sometimes they get misaligned when installing.

    Good luck to you.
     
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  8. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    15,729
    The Cold North
    Full Name:
    Tom
    You could also check the oil cooler lines. My car had a leak like you discribe and I cleaned the entire area,went for a drive and bingo...the cooler line was leaking at the oil filter housing.

    Just a thought

    Tom
     
  9. thecarreaper

    thecarreaper F1 World Champ
    Silver Subscribed

    Sep 30, 2003
    16,506
    Savannah
    Full Name:
    I NEED A JOB
    there is a dye that is used with a black light to show the path the oil is coming from. i love to use this stuff just for strange leaks such as this. just about any parts store should have it. michael
     
  10. speeder37

    speeder37 Karting

    Nov 18, 2003
    93
    Chicago
    Full Name:
    Matt
    The oil cooler lines are fine. I do not know if the rear main is rotational. I will ask. I will also recommend that they try the dye.
    Any thoughts on the build up of crankcase pressure?
     
  11. MarkCollins

    MarkCollins F1 Rookie
    Owner

    Jul 2, 2002
    3,199
    South England
    Full Name:
    Mark Collins
    it's not coming from the Gearbox breather is it? my 328 used to do this on a run, it was cured by adding a length of tubing up and over the rear wheel arch, I was told it was a recognised modification
     
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  13. speeder37

    speeder37 Karting

    Nov 18, 2003
    93
    Chicago
    Full Name:
    Matt
    Gearbox breather is fine.
     
  14. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    2,559
    Chicago
    Full Name:
    Philip
    I assume you are talking about engine oil escaping. As you know the crankcase vents though an oil separator (I assume the 328 is close in design to the 308). If this is clogged it will pressurize the crankcase and you'll start to get leaks where you don't expect them. The other thing you might look for in the general area is oil leaking down the engine mount studs.

    If it is gearbox oil, when used at the track, my 308 would push oil out past the diff seals and then it would go everywhere from the centrifugal force. The issue was the breather pipe on the tranny was blocked and as a result, when the gear oil started to evaporate at elevated temps, it would pressurize the case and then I'd get blow by. One week after being at the track I pressed the cap on the breather and it "pssshed" for 20 seconds releasing the pressure build up...

    If the shift shaft seals are gone, engine oil will flow into the trans causing the trans to overfill, resulting in excess pressure in the trans, and, well, you know the rest of this story.
     

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