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Oil Leak

Discussion in 'E46 (1999-2006)' started by Canuck2010, Feb 10, 2010.

    Canuck2010 guest

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    My 2000 323it is dripping oil under the engine. My car has 138000km on it. The dealer says it is a leaking rear main seal. The shop I dealt with when I lived in Florida says they have never has to replace a rear main seal.
    I have had the gasket on the oil filter mount replaced when it began leaking.

    Has anyone had a rear main seal problem?
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    tiFreak

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    I've seen them leak, where do you live now? if it's someplace where it gets cold in the winter the hot/cold cycle can make it fail, in Florida that obviously wouldn't be a problem

    Canuck2010 guest

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    I have moved back to Canada so the heat-cold cycle could be the problem
    Thanks
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    tiFreak

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    Canada, eh? should have been able to figure it out from the screenname :eek:

    mose121 guest

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    I live in Pittsburgh where it's also very cold in the winter and we never see this. It's much more likely that it's the oil filter housing gasket again or your valve cover gasket is leaking. Has the valve cover gasket been replaced? They usually need done every 60-70,000 miles. I even see them leaking at 50k. Back of the motor makes me think it's the valve cover dripping down. They always leak from the back corner, particualarly if they've been replaced before as it's a real PITA to seal that corner under the firewall properly. Even dealer techs frequently screw this up. I had a client try on his own to replace his three times and failed to seal that corner all three times. He finally just had us do it. It could also be the crankcase vent valve, but it would have had to been leaking for a while now. Remove the oil cap while the endine is running, if you hear a noise like a duck being strangled (honking noise) you need a new cc vent valve and hoses. If the oil cap will not come off, you really need a cc vent valve and hoses!

    Canuck2010 guest

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    Thanks for the info. I will look into these items before opting for the seal replacement.
    The leak isn't big but I just can't stand to have a leaky car. After all it isn't British!!
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    Zeichen311

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    Slightly off topic question, but: How does this work for you? :confused:

    I have a 2001 E46 (M54 2.5L) and on that, if you open the oil cap with the engine running, it immediately shuts down. It is so rapid, undramatic and repeatable that I can only conclude it's some kind of safeguard (emissions?) in the DME. The engine just won't run unless it is sealed up tight.

    Is there a trick here or is popping the cap verboten on newer engines? (As you see I never remembered to ask my dealer's techs about this.:eek:)
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    John in VA

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    I thought this was due to the massive vacuum leak created by removing the cap.
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    az3579

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    I thought this applied to all vehicles. If I remove my dipstick, even, while the engine is running, then it runs badly or dies.
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    Zeichen311

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    It creates a leak in the crankcase ventilation system, actually, but there's no mechanical reason an engine can't run with the filler cap open. This is the first one I've had that couldn't.
    That's what leads me to suspect it's related to emissions controls. An open CCV system allows oil vapors to escape into the atmosphere--I can understand newer, low-emissions engines not allowing themselves to run in that condition. So I wondered how mose121 managed it!

    (By "newer" I mean sometime after 1993, the last time I bought a car before the Bimmer in '01.:))
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    tiFreak

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    I've only seen it happen on BMWs, since they have the crankcase vent valve, just about all the Hondas/Chevys/Subarus/etc. I work on run just fine with the oil cap off

    mose121 guest

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    both my 95's (M3 and 318ti) as well as my 99 328i run with the oil cap removed, albeit not very smoothly with the obvious vacuum status. The 328 made the "honking duck" noise previously, which went away as soon as the cc vent valve and hoses were replaced. If the car is stalling out I think you problably have a vacuum leak already, and by removing the cap you are increasing the size of the leak to the point where it won't run anymore. Maybe check the intake throttle boot, as they commonly rot and tear open and sometimes don't immediately set a CEL/SES warning.
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    Zeichen311

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    Reasonable deduction but no, it has done this since new. Your '99 328i has the M52TU engine and a different DME than the M54, so we haven't eliminated the possibility this is a "feature" of the newer engine.

    Assuming I remember, I'll inquire when I next visit the dealer. It's gonna bug me now. :)

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