Jump to content
SAU Community

Recommended Posts

my GT40 has the oil restrictor built into the cartridge, but it's plain bearing. have you guys heard of plain bearing GT's suffering the same fate you're talking about above? or is it just the ball bearing cores?

also i'm using -6 braided speedflow lines, is there any way your lines can be too big? i'm worried that it will take a while for that volume of space to be filled with oil on start-up that's all. it's high mounted so the oil will probably drain back into the block when the car is turned off :P

hi i have fitted a few different garret turbo's to rb 26 and most of them will need a restrictor , rb 26 engines have one of the most high oil pressures out of everything i have had instances where engines have been making 50 psi oil pressure at idle , this is to much for a ball bearing turbo turbo at idling speeds and will push oil past the seals and cause it to blow blue smoke at idle ,you need to be using between .9 and 1.1 mm restrictor it does not have to be built into the turbo it can be anywhere in the supply line this will drop your idling pressure to around 10 - 14 psi the oil pressure will increase as the engines revs increase , it would pay to put a oil pressure gauge after the restrictor so you can keep an eye on it

An oil restrictor will increase pressure, not drop it!! It sill restric volume, not pressure! If you mean the pressure in the core itself will drop, then yeah it will.

Edited by Mik
An oil restrictor will increase pressure, not drop it!! It  sill restric volume, not pressure! If you mean the pressure in the core itself will drop, then yeah it will.

Mik,

Remember that the oil from the oil pump has more than one option - it goes into the motor as well as the turbo. Fitting a flow restrictor on the turbo will not change the pressure upstream worth a damn but will reduce the flow and hence pressure downstream - ie in the bearings and around the seals where it counts.

  • 3 weeks later...

Hey there guys, its seems appropriate to re-open this thread now since I have just taken my car down to the Collie track and guess what?

I think I may have pushed oil past the Turbo seals...

Car went great for just a handful of laps then suddenly lost power.. looked in the rear view mirror to see a large cloud of blue smoke.

This morning, there is a small pool of oil leaking from my BOV's...

Motor seems to run alright though, so hopefully no damage done..

What are people's experiences when this has happened? Just clean out all the intercooler and piping? Fit a restrictor to the turbos and she'll be right? Do the turbo's need to be taken off and looked at?

Or is there something darker awaiting me...

:(

--as a side note--

Oh! I should mention this also. When I got my turbos (they are ball bearing) and spun the compressor wheel on them, they didn't spin for more than about a second. I figured they just needed some oil. Once fitted to the car and they had done some dyno work - I would take the car home and switch it off. If I listened very closely, I could ~just~ hear them spinning down.

Since coming back from the track, you can ~easily~ hear them spinning down - they are MUCH louder.. although my mechanic listened to it and said all the noise just appears to be 'suction' at the pods.. Doesn't sound like bearing noise or anything... Do these things "loosen" up? I am a little worried by the 'change' as I would have thought ball-bearings would be free'd up from day one...

Hey there guys, its seems appropriate to re-open this thread now since I have just taken my car down to the Collie track and guess what?

I think I may have pushed oil past the Turbo seals...

Car went great for just a handful of laps then suddenly lost power.. looked in the rear view mirror to see a large cloud of blue smoke.

This morning, there is a small pool of oil leaking from my BOV's... 

Motor seems to run alright though, so hopefully no damage done..

What are people's experiences when this has happened?  Just clean out all the intercooler and piping?  Fit a restrictor to the turbos and she'll be right? Do the turbo's need to be taken off and looked at?

Or is there something darker awaiting me...

:(

--as a side note--

Oh! I should mention this also. When I got my turbos (they are ball bearing) and spun the compressor wheel on them, they didn't spin for more than about a second. I figured they just needed some oil. Once fitted to the car and they had done some dyno work - I would take the car home and switch it off. If I listened very closely, I could ~just~ hear them spinning down.

Since coming back from the track, you can ~easily~ hear them spinning down - they are MUCH louder..  although my mechanic listened to it and said all the noise just appears to be 'suction' at the pods..  Doesn't sound like bearing noise or anything...    Do these things "loosen" up? I am a little worried by the 'change' as I would have thought ball-bearings would be free'd up from day one...

This sounds a little different then the normal oil pressure on turbo seals

The engine would have been up to temp by the time you ran into a problem yes?

Are you running std oil pump?

What turbos are you running?

Are you sure you did have an oil breather problem out of the rocker covers (to much oil to the from head constant high revs with poor draining) as a friend did this recently made a hugh mess in the engine bay and there is a connecting pipe to the intake which could explain the bovs

Are you sure you did have an oil breather problem out of the rocker covers (to much oil to the from head constant high revs with poor draining)  as a friend did this recently made a hugh mess in the engine bay and there is a connecting pipe to the intake which could explain the bovs

thats what im thinking myself :(

This sounds a little different then the normal oil pressure on turbo seals

The engine would have been up to temp by the time you ran into a problem yes?

Are you running std oil pump?

What turbos are you running?

Are you sure you did have an oil breather problem out of the rocker covers (to much oil to the from head constant high revs with poor draining)  as a friend did this recently made a hugh mess in the engine bay and there is a connecting pipe to the intake which could explain the bovs

Hi Pete, yeah I had hoped it was this too. We checked the inside of the pipes from the back rocker cover. They were both 'reasonably dry' although the one on intake side did have a little oil in it.

The thing which made us go to turbo seals was that we popped off the silicon pipe leading off the compressor side of the turbos (the bit that says "twin turbo") and that had oil in it. (quite a bit). So figured this must be it?

Does that sound right?

in answer to your questions though:

Yes the engine was up to temp.

I can only 'assume' the stock internals and oil pump are standard, but can not be sure of what work was done prior (I think its a stock internal job though)

And I am running the 2560r, the -7 though, not the -5 like you.

I didn't fit restrictors because most felt they already had them and Turbotech said I wouldn't need them.. but er.. they might be wrong? :(

how much boost and what condition is the motor?

is it a little tired at all?

hmm.. I don't think I like where that question is heading...

I refuse to answer that on grounds that it sounds expensive... :)

...ok, I'll answer. Don't know true km's, but it had 150 across all six when we did a compression check a couple of months back. Haven't done a leak down test though. Might do another test to see if anything has changed.

And it was running about 1.2bar

Now I have had time to think about it - I think its almost certainly oil past the turbo seals since there is oil in pipe coming off the compressor side of the turbo (ie in the piping marked 'twin turbo') . It can't have got in there any other way can it?

And if this is the problem, then the question is: what oil pressure "should" the turbo oil line be restricted to? Has anyone got an actual figure? (that way I can put a gauge on it rather than just picking a size of oil restrictor out of the hat)

Now I have had time to think about it - I think its almost certainly oil past the turbo seals since there is oil in pipe coming off the compressor side of the turbo (ie in the piping marked 'twin turbo') . It can't have got in there any other way can it?

blowby, thats the usual one. if the rear seal is gone then it wont have oil in the intake side

sounds like you might just need a catch can :) simple fix and inexpensive.

To test, just get a coke bottle or something and see what happens, take the pipe off that goes back into the intake

blowby, thats the usual one. if the rear seal is gone then it wont have oil in the intake side

sounds like you might just need a catch can :) simple fix and inexpensive.

To test, just get a coke bottle or something and see what happens, take the pipe off that goes back into the intake

Yup. Well. Now she's had a compression test and it looks like I've all but lost number 2.

The question on my mind now is if I had have had a catch can, might this have been avoided?

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


  • Similar Content

  • Latest Posts

    • Those 2 solenoids in that assembly I mention, are the PWM solenoids for torque converter lock-up clutch & EPC (line pressure control) ~ when most folks hear of 'solenoid failure', the tendency is to think electrical failure...but fact of the matter is, especially wrt the EPC solenoid (which is moving/running all the time), you can have an electrically 'good' solenoid, that's absolutely broken/worn out mechanically inside...ie; valve plunger return spring rubbing against spring retainer plate, lowering preload pressure.. ...and the solenoid armature extension limit spring wafer with bad wear/broken off petals... ...and if there's ever been any metal flying about, damage to the valve plunger end itself... ...the stuff one never really sees, unless you go the whole 10yards trying to answer the question "why is my line pressure screwy, but TCU isn't flagging any EPC solenoid fault?"...and carefully dissect the solenoid. Worst (and most probable) scenario is when the plate spring petals break off, they get held by the magnetic flux, get mashed up by the armature into little bits, which end up in the space between the armature & shading core bore, and things get stuck or randomly jam up, and your line pressure goes flat and doesn't change...and the TCU never sees it, as it doesn't actively monitor LP... ..then it gets into insidious land, if you end up with lower than expected line pressure...lets say high clutch..and the lower pressure causes it to slip ~ when I say 'slip', think say 2000rpm on the drive plates, and 1800rpm on the driven plates, because the slip is making them under-rotate by 200rpm ; you get all the usual nasties like heat and band/clutch wear, but even if it's only 20rpm slip the same thing happens...and... you'll hardly ever pick this up driving the thing with the torque converter active as it effectively masks these sorts of slippages that are line pressure related ...(the newer TCUs can detect clutch slip rate)...just  FYI as it were...  
    • There's nothing that some paddle pop sticks and extra cable ties can't fix.
    • Hey guys, so Golebys has good prices on Bosch injectors, and also sell an adaptor to go from 1/2 length injector to standard with the Nissan 10.5mm top seal.  Does anyone know if that adaptor is to suit the 14mm or 11mm injector tops?  And re. The bottom seal, to suit my standard RB20 intake, would I be right in saying I can just slip the 14mm square section O ring over the bottom of the new injector and done? Thanks in advance guy, Cheers, Rowdy
    • F my life. I was changing the oil on my R32 GTR today as usual and ran into a bit of a snag. I drained the oil out and was getting ready to finish the job by tightening the drain plug, however The stupid magnetic oil drain plug snapped in half, right at the magnet part. After about an hour of trying to remove it, I used a drill bit, which unfortunately pushed the magnet all the way into the pan, and just leaving the hollow threaded part of the bolt remaining. I was able to remove the hollow portion of the bolt from the oil pan with some pliers but the magnet is still in there.  So, the question is, should I drop the oil pan to get the magnet piece out, or is it okay to leave it in there? I really dont want to drop the pan, i'm about to go nuts.  PSA: Do NOT buy a BLOX magnetic drain plug. This is the one i had.    https://bloxracing.com/products/magnetic-oil-drain-plug-m12x1-25mm?variant=37131252859052&country=US&currency=USD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=CjwKCAjw47i_BhBTEiwAaJfPpgti1D2JwO7TDuMpXuqeQPCuIQSAfwxpWQH5rF9MD7sm5SCZDWLR_RoC_YoQAvD_BwE    
    • I actually have an aftermarket hanger, the detschwerks x1 hanger, but my dw420 has never really sat in it correctly, good to know I can just modify it a bit to suit. Yeah cheers man will definitely have a play with it and hope it solves my dramas.
×
×
  • Create New...