Dipstick Tube Question | FerrariChat

Dipstick Tube Question

Discussion in '308/328' started by millsj, Jul 1, 2020.

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  1. millsj

    millsj Karting

    Oct 17, 2011
    214
    Charleston, SC
    Full Name:
    Joe
    I recently replaced the shift shaft seals on my '86 GTB and have an oil leak just below the dipstick tube. Today, I finally had a chance to put the car up on the lift to try to pinpoint the leak. I should know more by the morning, but some strategically placed paper towels seem to indicate the leak is originating where the dipstick tube enters the sump.

    The leak occurs with the car parked, so the leak is originating somewhere where there is oil with the engine cold. Is the threaded collar that screws into the top of the sump submerged in oil when cold? If so, how much oil will come out if I remove this collar? My thought was to unscrew the collar, put thread sealant on it and reinstall.

    The good news is the shift shaft seal is dry as a bone. :)

    Below is the part I am referencing. [​IMG]

    Thanks for any insight.
     

    Attached Files:

  2. ferrariowner

    ferrariowner Formula 3

    Feb 21, 2014
    1,109
    Mansfield, TX
    Full Name:
    Ron
    Part of the dipstick tube that threads into the sump has NPT threads. Make sure they are wrapped with Teflon tape or pipe dope or it will leak.
     
  3. conan

    conan Formula Junior

    Nov 13, 2011
    389
    Here is a view with the dipstick fully inserted. In case you have the level above min, I guess there is a risk of oil leaking out if removing the assembly.

    It should not leak if the copper washer is in good shape and there is no damage to the tube surfaces seen below.

    Image Unavailable, Please Login
     
    waymar likes this.
  4. Brian Harper

    Brian Harper F1 Rookie
    Owner Silver Subscribed

    Feb 17, 2006
    4,078
    San Jose area
    Full Name:
    Brian Harper
    In my case the answer was yes. I don't remember why I removed it, but I was unpleasantly surprised to find that joint below the oil level line. Well, not for long, but initially.
    If your oil level is at max per the recommended procedure then all of the oil that will drain from the oil cooler, oil filter, oil galleys, heads, etc. back into the sump will drain onto your floor.
     
  5. pappy.72

    pappy.72 Formula Junior

    Nov 13, 2010
    516
    Elgin, IL
    Full Name:
    Dave
    Would be a good time to do an oil change if you are looking to fix a leak at this spot.
     
  6. millsj

    millsj Karting

    Oct 17, 2011
    214
    Charleston, SC
    Full Name:
    Joe
    Thanks for the input. I am cautiously optimistic at the moment. Turns out the leak was not at the collar. I must have put thread sealant on that joint when I reassembled. I put it on the temp sensor, so that would make sense. The leak was at the cap nut on the dipstick tube. I think the tube wasn't square when I screwed the nut down and it didn't screw all the way down to seal. I'll update with a definitive answer, but I think I am good.
     
    waymar likes this.
  7. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    NPT on a european car ? Thats unusual
     
  8. ferrariowner

    ferrariowner Formula 3

    Feb 21, 2014
    1,109
    Mansfield, TX
    Full Name:
    Ron
    Your right Mike its probably Metric pipe thread, I never used a gauge to see what it was. But it does need Teflon tape :)
     
  9. conan

    conan Formula Junior

    Nov 13, 2011
    389
    I do not remember it was tapered. There was a copper gasket which is the sealing solution to the sump, at least on the eu 328.
     
    Steve Magnusson likes this.
  10. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,828
    Isle of man- uk
    No such thing as metric pipe thread, BSP is a normal pipe fitting and very similar to NPT. One is about 10 tpi and the other is about 10.5 tpi on a one inch pipe is i remember correctly.
    You can actually run the die nut of one down the other, and it will fit with a bit of sealant.
    I used to go to the states on ships and could not get BSP fitting, only NPT which is a US thread, so we put a tap or die on them to get a fit.
    You can also get tapered or straights threads in these
     
  11. Irishman

    Irishman F1 Rookie

    Oct 13, 2005
    3,518
    Raleigh
    Full Name:
    Kevin
    My recollection is the 'base' does have a copper (crush?) washer. This base part is independent of the dipstick tube which one can f _ _ _ up easily if not careful. It's also easy to cross thread or otherwise not properly install the upper part of the dipstick tube. So beware : - ). Teflon pipe sealant seems fairly safe to me but should not be necessary.
     
  12. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    The base does have a crush washer, yes.
     
  13. millsj

    millsj Karting

    Oct 17, 2011
    214
    Charleston, SC
    Full Name:
    Joe
    I finally got it sorted. I actually had two problems, both self-inflicted. My first issue was that when I reinstalled the dipstick tube, the cap nut didn't screw all the way down. If you look in the picture earlier in this thread, the nut hung on the top of the silver end of the dipstick tube. There is a little lip there and the nut caught on it and didn't screw all the way down. I got this corrected, but it still leaked. It was greatly reduced, but still dripping. While correcting issue #1, I realized I had somehow overfilled the oil. If you look at the same picture above, you can see that the MAX fill mark is just below the joint that was leaking. With my oil overfilled, my leaking joint was completely submerged in oil. Now that the nut is screwed on properly and the oil is at the correct level, all is good again. I can now finally say the shift shaft seal job is completely finished.

    Thanks again for all the assistance.
     
    waymar and Milkshaker0007 like this.

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