Rebuilding Turbos

Discussion in 'Z32 Technical' started by Shane001, Aug 5, 2018.

  1. Shane001

    Shane001 Well-Known Member

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    Checking a few things on the racecar this afternoon, and noticed the passenger side exhaust housing was wet with oil :(

    Couldn't see anywhere it was leaking from other than the turbo itself, so wiped it up as much as I could, then ran the car for a bit and sure enough, was a drip of oil at the bottom of the exhaust housing again. Looks like it's seeping down between the housing and the bolt plates.

    So I guess this means the rear seal is gone :(

    Had a look online, a few videos on pulling these apart and rebuilding them. Haven't had a good look yet. But looks like you can buy full bearing/seal kits for them. Mine are high flowed though so not sure if that means bearings and seals will be different.

    Anyone had a go at rebuilding these themselves?
    I can't afford to be paying for turbo rebuilds atm. Pretty much would rule me out of Bathurst next year :(
     
  2. IB

    IB ?????

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    Zcar91 & I have rebuilt a couple of pairs of stock turbos. Only one pair in use so far and only a couple of thousand one.

    You need some good circlip pliers, including a big pair that lock for the inlet housing. We turned a pair of needle nose pliers into long thin circlip pliers for the small internal circlips.

    Any markings you make to re-align rotating assembly need to survive cleaning.

    Good luck.
     
  3. Shane001

    Shane001 Well-Known Member

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    Thanks Ian. There's a couple of videos online, including of the 300ZX turbo's, dismantling and rebuilding them. Doesn't look too hard, attention to detail and put them back together exactly as they came apart and it should be doable.

    It's strange though where the oil is leaking. I would have though the oil would leak into the housing and burn out the exhaust, not seep out where the housing joins the core. And I haven't noticed any significant smoke out the exhausts including the last time out on track.
     
  4. Madcow

    Madcow Active Member

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  5. Shane001

    Shane001 Well-Known Member

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    Interesting, surprised no one has thought of this before.

    Our turbos are journal bearing though (don't know why but I always thought they were ball bearing), and I'm still running the factory oil cooler bypass setup, so they're only seeing 55ish psi max anyway. For anyone running full flow this would be a good idea though.
     
  6. RynoDrifterZ

    RynoDrifterZ Member

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    On the topic of rebuilding turbos, I have purchased a pair of hi flow turbos and have been told they could do with a rebuild, they’re gt2871r cores. If someone wants to do the rebuild for me and I can buy the kit
     
  7. Shane001

    Shane001 Well-Known Member

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    Removed the dump pipe this afternoon, perfectly dry and clean all the way down the dumps, into the test pipes, and the exhaust housing. No signs of oil. Also can't feel any forward/rearward movement on the shaft.

    I would think if the exhaust seal was leaking there would be signs of oil in the exhaust housing correct?

    So I'm hoping it's not the turbo internals, so that leaves the oil feed pipe on the top of the turbo. Either way it's engine out as there's no way to get to it with the engine in. Hopefully that's all it is and I don't have to do a turbo rebuild.
     
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  8. IB

    IB ?????

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    I would have thought you could get to the passenger side turbo oil flare but without pulling the engine. You'd need to remove a few things that you'd have to remove to pull the engine, so no great loss in trying. You might need to modify a spanner.
     
  9. Shane001

    Shane001 Well-Known Member

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    A couple of the new coolant hoses on the rear of the engine still have a slight leak, so need to pull the engine anyway, going to RTV the ****ers! Plus I've had the engine out so many times this year now it's almost second nature lol.

    But will have a closer look when I get to this. Currently working on suspension upgrades.

    What are peoples thoughts on my diagnosis that it's unlikely to be the rear turbo seal? If this was leaking would you generally expect to see oil residue in the turbine housing and dump pipes?
     
  10. Martin Williams

    Martin Williams Active Member

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    I agree with you. In my experience the first sign that the turbo seal is leaking is smoke from the exhaust on start-up or idle. To have a bad enough seal leak to show up on outside of exhaust housing I would expect to see some oil residue in turbine housing or blue smoke from exhaust. More like to be a crack in oil inlet flare or pipe.
     
  11. Shane001

    Shane001 Well-Known Member

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    Thanks Martin, that's what I figured. Big sigh of relief not having to rebuild the turbos.
     

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