Jump to content
SAU Community

1995 R33 Gtr Oil In Intake Pipe

judasentinel

By judasentinel,
in Engines & Forced Induction

 Share

Recommended Posts

judasentinel Explorer

judasentinel

Posted
Posted

I have a 1995 R33 GTR, and have been noticing oil coming into the intake pipe between the rear MAF and the rear turbo.

Someone suggested it could be from the exhaust crankcase ventilation (PCV) connected to the rear intake pipe, so I installed a catch can between the pCV and the rear turbo. However, the oil is still showing up in the rear MAF intake hose. I see oil coated on the turbo side of the MAF.

I have twin BOVs recirculating back to the Y pipe between the turbos, and when I rev the engine, I can see the air coming back out of the rear MAF (and not the front). The front MAF and turbo intake pipe are clean, which makes me think that the oil might be coming in from the rear turbo. This theory however, seems to suggest that the rear turbo may be leaking and blown.

However, the car boosts fine, all the way up to 1 bar without any hesitation. If the rear turbo was blown or had issues, would the car still boost? There is no oil leak under the car, and no black or blue smoke coming out of the exhaust. It idles fine as well.

I am totally stumped. I dont want to push the car if the rear turbo is blown, because some people have suggested it might be, but then others say that if it were, I wouldnt be able to boost the car to 1 bar.

Any ideas or suggestions to check?

Please help me as I want to make sure that the car is fine.

Thank you,

Munib

Link to comment
Share on other sites
djr81 Grand Master

djr81

Posted
Posted

The blowby that gets sucked out of the head by the turbo (As opposed to the drivers side which goes into the engine on over run) goes to the rear turbo. This is almost certainly what you are seeing. Usually it ends up dripping out of the bovs. Even the crack pipe priced Nismo catch can doesn't stop it from happening.

Link to comment
Share on other sites
judasentinel Explorer

judasentinel

Posted
  • Author
Posted

So how does one discern if it is the blow-by oil or the turbo is shot/leaking oil from the compressor side? If there is a compressor oil seal leak, will it also go into the intake piping? If so, how do we determine what is actually happening without removing the turbo piping?

Also, if there is an exhaust oil seal leak, will that also cause the oil to come up front of the turbo towards the compressor and go into the intake piping?

Surely, there would be a way to identify if the oil is from the blow-by or the turbo oil seal leak....?

Link to comment
Share on other sites
judasentinel Explorer

judasentinel

Posted
  • Author
Posted

In addition to this, I do not see any oil at all in the catch can....maybe a tiny droplet, but that's all. And while the car is running OR I am revving the engine, I do not detect any suction from the catch can into the hose I am running to the rear turbo-MAF intake pipe. If this means the turbo is not spinning, it wont be sucking in any air from that hose, could this also be causing the recirc from the BOV to come out of the rear MAF? When I let go of the accelerator, I can see air/oil blow out of the rear MAF filter. This has me perplexed.

Link to comment
Share on other sites
judasentinel Explorer

judasentinel

Posted
  • Author
Posted

If it is just blow-by coming back from the BOVs, and oil is returning with it, why is it escaping though the rear MAF only, and out the rear filter, and getting sucked in by the turbo since the whole point of recirc is to keep the metered air within the intake system?

I dont know if what I am saying makes sense....the BOVs recirculate air, it comes back into the MAF-turbo pipes (through the Y-pipe that connects to both turbos), and ideally, should at stage be sucked back in by the turbos. Instead, it is escaping out of the rear MAF...

Link to comment
Share on other sites
fatz Grand Master

fatz

Posted
Posted

If it is just blow-by coming back from the BOVs, and oil is returning with it, why is it escaping though the rear MAF only, and out the rear filter, and getting sucked in by the turbo since the whole point of recirc is to keep the metered air within the intake system?

I dont know if what I am saying makes sense....the BOVs recirculate air, it comes back into the MAF-turbo pipes (through the Y-pipe that connects to both turbos), and ideally, should at stage be sucked back in by the turbos. Instead, it is escaping out of the rear MAF...

That is just because of the stock setup it takes the easy way out
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      Boost level and torque curve

      By Duncan · Posted

      That is typical (for a rb at least) with a medium to large turbo, noting the format of the graph is probably misleading what you see a little (half portrait width but full height, in landscape it would look quite different) Basically until it hits target boost the torque curve is rising steeply, when that is 4000+ rpm it is not great to drive since almost all of your life is between 1,000 and 3,000 rpm. Once you hit target boost the wastegate opens and torque stops rising so quickly. From there the shape of the curve depends mostly on the cams and where they have a peak vs the rev limiter
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Last of the maintenance items for now....not sure why but the drivers side window switch had heaps of wear on the right front and right rear switches Unfortunately, unlike earlier Skylines the controls are bolted to the door trim from the inside. So....off the with door trim. There are bolts or screws: Behind the door handle cover, pop it off from the handle side Under the rubber trim at the bottom of the door pull (also just pops up) Behind the courtesy light at the bottom. Other than that, just window down then pop off the usual selection of push in clips around the perimeter and the trim lifts up Interesting that they have a bolt on cover instead of the old school plastic held on by goop....I guess they prioritised sound levels over price Then, 2 screws and 2 plugs to replace the switch (looks identical to the Fuga/Q70 one incidentally) and put it all back together. Also much better
    • thx78
      Boost level and torque curve

      By thx78 · Posted

      ok I understand, but the majority of turbo vehicles lose torque, or have a flat torque curve after the spool.  hence my initial misunderstanding. I didn't think this type of curve was possible  
    • GTSBoy
      Boost level and torque curve

      By GTSBoy · Posted

      It is completely normal. Your original understanding is what was wrong, not what you see in the charts.
    • thx78
      Boost level and torque curve

      By thx78 · Posted

      made with turbo and tuned by (hypergear)
×
×
  • Create New...