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Major oil leak above oil pan

Discussion in '3rd Gen 4Runners (1996-2002)' started by Joseph Lenehan, Sep 24, 2021.

  1. Sep 24, 2021 at 1:12 PM
    #1
    Joseph Lenehan

    Joseph Lenehan [OP] New Member

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    2020 Tacoma wheels
    Hey, new to the forum. I have a 96 SR5 4x4 (with a stick too :))
    Hoping someone could help out with an oil leak I have. I’ll post a picture below after I explain a little bit.
    A little reference on the car, it has just under 200k, sat for around 7 years in front of my patent’s house when it needed a clutch, and has definitely seen better days.
    Back to the problem, it’s leaking very badly above the oil pan. It is very difficult to see where it’s coming from however with the crank pulleys and belt and what not, so I’m hoping someone has experienced this before. It has had a timing job done around 8 years ago. Not sure if seals have been replaced.

    The leak is right above the oil pan (it is not the oil pan, I've replaced the pan and sealed it correctly with FIPG), and it occurs a good 20-30 seconds after the car has been started.

    One more thing to note is that I dropped the oil pan and noticed a small half an inch crack in the oil pump assembly. Not sure if it’s a big deal or not but I really need some guidance.
    Let me know what you guys think, here’s the picture:
    IMG_0203.jpg

    Any help would be very appreciated, the rig has been on jack stands for a little over 2 weeks now all torn apart. Thanks!
     
  2. Sep 25, 2021 at 4:00 AM
    #2
    HiSeasMan2019

    HiSeasMan2019 New Member

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    I believe the Car Care Nut on Youtube mentions that the front crankshaft seal is a known problem - he also said it wasn't too bad to replace if you're mechanically inclined. He has a great series about the 4runner.
     
    Robruns likes this.
  3. Sep 25, 2021 at 10:49 AM
    #3
    negusm

    negusm New Member

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    Is this the 3400? If so, then yeah, that seal is easy to replace and should be done at the second T-Belt change (at least) along with the cam shaft seals. GET TOYOTA or the TOYOTA Supplier seals! I got some in a T-Belt kit that were not as beefy as the OEMs! Everything was OEM supplier parts but those. I threw them in the trash.
     
  4. Sep 25, 2021 at 1:35 PM
    #4
    PhantomTweak

    PhantomTweak New Member

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    None. Bone Stock. EXCEPT: Brushguard, tow hitch, both welded to the frame. It's good to have friends and a fully equipped garage!
    I've replaced the front crankshaft oil seal on both my 87's several times each. The hardest part, really, is torquing down the bolt afterward. Put it in gear, block the rear tires, parking brake on, it's just a lot of OOOOMPH to put on the bolt, really. 165 ft/lbs, IIRC LOTS of OOOOOMPH! on your part.

    Bear in mind 2 things. 1) The seal in in the oil pump, not the block. You have to replace the oil pump o-ring when you pull it to change the crank seal. It's a bit of a PITA to keep in place in the oil pump's groove during installation, and very easy to pinch a short section of it. Instant leak. I put a little thick, heavy, sticky grease in various points around the groove, and it holds the seal in the groove very nicely.
    2) The front crank seal wears a groove in the crankshaft over the years/miles. It leaks, even with a new seal on it. "They", and I'll be darned if I recall just who "they" are right now, make a front crankshaft seal that rides in a slightly different spot of the crankshaft, so you essentially prevent that leak from recurring.

    Be ready to replace the harmonic balancer, while you have it off. It's essentially two pieces, separated by a rubber gasket, or whatever it's called. The rubber breaks down over time, and the two halves shift relative to one another. Bad, as it won't run the belts right any more.
    Don't loose the key when you pull it off, either! Darn frustrating, let me tell you, especially for us shadetree mechanics. The darn key vanishes in the clearest areas...

    Other than all that, easy peasy :D
    Have fun!
    Pat☺
     
  5. Sep 25, 2021 at 11:32 PM
    #5
    Joseph Lenehan

    Joseph Lenehan [OP] New Member

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    @negusm, yes it’s the 3400. I’m thinking about getting timing belt kit on eBay, i’ll drop the link below, but it says everything included is oem. What I’m thinking now is that i’ll do the job, and while the belts and timing covers are off, i’ll inspect the crank and cam seals along with the oil pump to try and pinpoint the leak. I might even use some UV dye to make sure I get the the leak the first time around and not have take it all apart again. It It is the 4wd, and the front diff is already pulled, so an oil pump leaking would only be, in my opinion, a minor hour/ 2 hour job max. Here’s the ebay link, let me know what you think:
    https://www.ebay.com/itm/OEM-Water-...a-Tundra-4Runner-3-4L-V6-Engine-/373724994395
     
  6. Sep 25, 2021 at 11:42 PM
    #6
    Joseph Lenehan

    Joseph Lenehan [OP] New Member

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    @PhantomTweak, before I start this job I’ll be ordering/ renting some special tools to make my life easier when doing this job, and to get pulley bolts loose as well as tight. With the money i’ll be saving by doing the job myself, I just see it as a minor expense (shop quoted me $2700 for the pump and full timing belt job). Also, i’m not entirely sure you’re correct about the oil pump o-ring having to be replaced along with the crank seal… Maybe it’s different for your 87, but from the videos i’ve seen and some other threads, the crank seal is separate. I will take into consideration the “groove” you are talking about, hopefully I don’t run into this. Worst case i’ll just have a leaky 4runner.

    I also plan to reuse my crank pulley/ harmonic balancer just due to the fact that it is much more simple part to replace if it ends up going out. But, if mine is really bad, I guess I could just throw a new one in.
     
  7. Sep 26, 2021 at 10:12 AM
    #7
    negusm

    negusm New Member

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    That ebay kit looks legit to me. As long as what you get comes in the Toyota packages like shown.
     
  8. Sep 26, 2021 at 12:26 PM
    #8
    PhantomTweak

    PhantomTweak New Member

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    None. Bone Stock. EXCEPT: Brushguard, tow hitch, both welded to the frame. It's good to have friends and a fully equipped garage!
    So far, every time I've used the "tap the starter" method to break the bolt loose. It's not failed me yet. The first couple of times, I was scared to death of doing it that way, but now, it's just normal for me. Quick, easy, only thing to remove is the belts and the center conductor on the distributor. The starter is stronger than I am, and works faster. Not to mention it works for free :D

    Since you'll need to remove the oil pump, as the crank seal is mounted in it, I've found that it's seal is almost invariably gotten no good since the last change. Kinda like the distributor, or the thermostat's o-rings. Or, even more so, the PCV grommet. Point being, I've found that if you pull the oil pump, for whatever reason, it's a good idea to have a new seal for it. Chances are, you'll need it. Just my experience, of course.
    Having said that, since I spent most of my ownership time in Yuma, Az, it may have to do with the heat. I know it's hard s heck on rubber.

    All these seals I was talking about are a small investment. A new sal doesn't hurt anything, and, if they're OEM, you know roughly their lifetime, knowing what you removed.
    Then again, I may maintain my trucks too much, if that's possible. Every year a tune up, plugs, wires, belts, hoses, coolant, etc etc. Every two, give or take, PCV valve and grommet, and that grommet is invariably gotten hard and brittle, and valve cover gasket set, as well as oil in the engine, transmission, and differentials. 99% of the seals on ANYTHING I take off get replaced. Most need it too.

    Nothing wrong with reusing the harmonic balancer. Mine are all still factory original. I just mentioned it, as I've seen numerous threads regarding the need to replace it. Just wanted you to be aware of the possibility.

    No matter what, you do the work yourself, even if you need to replace every piece involved, like the HB, etc, it'll still be a cheaper by far than the price you got quoted. Go for it!

    I feel it pays, but you do you :)
    Have fun!
    Pat☺
     
  9. Sep 26, 2021 at 12:30 PM
    #9
    negusm

    negusm New Member

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    Why do you have to remove the oil pump on the 3400 for the front crank shaft seal? I don't remember doing that last T-Belt change.

    -Mike
     
  10. Sep 26, 2021 at 1:14 PM
    #10
    PhantomTweak

    PhantomTweak New Member

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    None. Bone Stock. EXCEPT: Brushguard, tow hitch, both welded to the frame. It's good to have friends and a fully equipped garage!
    I may well be wrong, and frequently am, but I believe the front crank oil seal is mounted in the oil pump body. To remove it, you need to drive it out from the front. Without removing the oil pump, you can't get the seal out.

    Having said that, they may have changed the way the seal is mounted, so that you can pull it out of the oil pump from the front, now. The ones in my experience, so far, were both 87's, and to remove the seal, you had to drive it out from the front. It would come out, and install, fairly easily, especially with a press. Failing that, a large socket, just big enough to fit the seal, will drive it out, and press the new one in very nicely. A few taps with a rubber mallet, or the like, and voila, all done.

    As I mentioned, the hard part is getting the oil pump's seal, that goes round the outside of the pump, is a small, thin, rubber ring, in an odd shape, that sits in a groove on the oil pump. Getting it to sit properly, while putting the oil pump in place on the engine can be a real pain. That's why I suggested a dab of thick, heavy grease be applied in the groove on the oil pump. It holds the little PITA rubber seal in place while placing the oil pump on the engine, without interfering with the seals function.
    Otherwise, no matter how careful you are, chances are a small section will pop out, and not be visible. You tighten the bolts down, and boom, you cut the seal. Now you get to take everything back apart to re-replace the bloody malicious little seal.
    If you cut it, too, chances are it'll dump a lot more oil than might think it would, so be forewarned.

    Have a good time. I see the 96 is different in the oil pump, but it looks like the seal is still mounted in it. It has a different seal, but I still wager, from what I see in the FSM's pictures, that it's just as hard to get to stay in place. My experiences are going to be different, yes, but a lot is still the same basic procedure.

    Anywho, have fun!
    Pat☺
     
  11. Sep 26, 2021 at 1:16 PM
    #11
    Joseph Lenehan

    Joseph Lenehan [OP] New Member

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    @negusm, no, the pump doesn’t need to come off to get the seal out. I’m sure it’s a lot easier to remove and instal, but it can be removed without taking the pump assembly off.
    Also i’ll go ahead and order that kit. If anything isn’t oem, i’ll go ahead and see what the seller or ebay can do to get me reimbursed for the inferior parts and get oem from the dealer.
     
  12. Sep 26, 2021 at 1:19 PM
    #12
    Joseph Lenehan

    Joseph Lenehan [OP] New Member

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    2020 Tacoma wheels
    @PhantomTweak, it can be removed without taking the pump assembly out. There’s a special tool for it, “Timmy the Tool Man” on youtube has a great video on it. I’ve also seen some guys use a picks, or a screwdriver to remove it. Thanks for your input, i’ll definitely try some of what you suggested if I run into any problems.
     
  13. Sep 26, 2021 at 2:52 PM
    #13
    PhantomTweak

    PhantomTweak New Member

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    None. Bone Stock. EXCEPT: Brushguard, tow hitch, both welded to the frame. It's good to have friends and a fully equipped garage!
    Ahhhh! Ok, good. They improved the design. I like it.

    Tear it up! :D
    Pat☺
     
  14. Oct 13, 2021 at 3:34 PM
    #14
    Joseph Lenehan

    Joseph Lenehan [OP] New Member

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    2020 Tacoma wheels
    Hey, all here’s an update (finally) :
    My front crank seal was the culprit. It was pushed out decently far and not sealing whatsoever. It also appeared to not be an oem seal.. Guess someone before me when doing the job decided to put in an aftermarket seal and that’s what I believe caused the issue. As a precaution, I went ahead and put in a new pcv valve as well since it hasn’t been done for a long time. Not too sure if I mentioned that before.
    So after a new timing belt kit (seals, belt water pump, pulleys, tensioner, ect.), I started it back up and no leaks!! Really excited to be parking in the driveway again haha.
    Thanks for the help all!
    If you’re looking at a diy for the crank seal/ timing job, “Timmy the Tool Man” on youtube has a great in depth video on it that helped me out a lot.
     

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