Jump to content
SAU Community

Did a boost leak test, now I'm not making any boost

Custard

By Custard,
in Engines & Forced Induction

 Share

Recommended Posts

Custard Contributor

Custard

Posted
Posted (edited)

Did a boost leak test, now I'm not making any boost

Hi all. Before I start, my car is a 1997 R33 GTST with a standard turbo.

So today I decided I would perform a boost leak test while I was in fiddling with my new adjustable wastegate actuator. I only pressurised it to the point that my 5 PSI wastegate actuator opened, and I realised that my leak tester was leaking, so I stopped. I had connected the leak tester directly to the turbo inlet. Upon putting my car back together and going for a drive, I realised it was making no boost at all. The boost gauge rises until it hits zero and doesn't go any further. To eliminate my wastegate actuator from the equation I disconnected it, and then I saw a maximum of 3 PSI. 

The turbo I've been running is a used standard one that I put in when I bought the car, as I bought it with a blown exhaust wheel on the original turbo. The turbo has always made a funny high pitched whine when it comes onto boost, but it never got any worse or developed any shaft play so I didn't think anything of it. I've put over 10,000 kilometers on the turbo since putting it in. 

I took my intake pipe off to look at the turbo and noticed two of the blades have a decent sized chunk missing. Is it possible that those chunks have been missing the whole time and could explain the strange whine when the turbo spools up? I feel like I probably would have noticed the missing bits at some stage of my tinkering but it's possible that I did not. Would the turbo even create proper boost with such missing bits from the compressor turbine? If the damage to the turbo is new, how on earth would a boost leak test have damaged anything? I'm so confused about this whole thing - I'd be super grateful for some opinions from you guys.

Edited by Custard
Dobz Experienced

Dobz

Posted
Posted

Either way it's turbo off so get busy. When it's apart the cracked areas on the compressor should look quite bright if it's recent damage and more dull if old. Is it possible something was ingested into it?

Custard Contributor

Custard

Posted
  • Author
Posted
3 hours ago, GTSBoy said:

Oh, it's f**ked.

Haha, sure is. 

2 hours ago, Dobz said:

Either way it's turbo off so get busy. When it's apart the cracked areas on the compressor should look quite bright if it's recent damage and more dull if old. Is it possible something was ingested into it?

Already was up until 2:30 last night ripping the thing out, haha. It's an S2 turbo with a nylon wheel as far as I can tell, so I don't think I'll be able to determine it that way. I had the intake off to leak test it so it's possible, but I don't know what it could have been, and I can't find anything anywhere in the piping. I gather any bits of turbo/debris wouldn't have made it any further than my intercooler, but I can't find anything in there at all. 

hardsteppa Grand Master

hardsteppa

Posted
Posted

no, looks exactly like a nylon wheel, especially where it's broken.

Could have been something hitting it or could just be fatigue and breaking apart; they're old now and not the most durable part to begin with.

Custard Contributor

Custard

Posted
  • Author
Posted (edited)
11 hours ago, Dobz said:

It doesn't really look like a nylon wheel from the colour of it. Pull the compressor cover off and take some photos. What does the exhaust wheel look like?

 

It's definitely a nylon wheel, very obvious from the feel of flicking it with my fingernail. 

7 hours ago, hardsteppa said:

no, looks exactly like a nylon wheel, especially where it's broken.

Could have been something hitting it or could just be fatigue and breaking apart; they're old now and not the most durable part to begin with.

I'm thinking either a bit of crap came through my air compressor, or perhaps the pressure from the leak tester just hit it in a way it didn't like. Whatever I did, it broke before I drove it again - nothing happened when I actually started it up and drove it. Didn't hit a single pound of boost or hear anything weird when I got it back on the road, besides when I disconnected the actuator (and since it wasn't actually producing enough pressure to open the wastegate I chalk that extra 3 PSI up to the line that I left open on the charge pipe causing a rich condition).

6 hours ago, Dose Pipe Sutututu said:

Take it out, also throw your FMIC in the bin too and drop in another one.

Send it to HyperGear for a rebuild. 

Not very helpful mate, unlike some people I don't have thousands of dollars to throw at my car. I will be thoroughly checking and cleaning all piping and my intercooler and replacing my turbo with a good condition used unit, hopefully an R34 turbo. I will also be compression testing my motor to ensure nothing got in between my valves, but judging by how my car was running perfectly and actually surprisingly peppy making zero boost I would be very surprised if anything's happened to the motor.

Edited by Custard
Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

You'll need to pick all the fragments out of that fmic before your motor ingests all the fragments and you'll spend more than $150 replacing that fmic because a motor rebuild or swap I'm sure will cost at least 10x to 20x more than a replacement eBay FMIC.

 

  • Like 2
Custard Contributor

Custard

Posted
  • Author
Posted
7 hours ago, Dose Pipe Sutututu said:

You'll need to pick all the fragments out of that fmic before your motor ingests all the fragments and you'll spend more than $150 replacing that fmic because a motor rebuild or swap I'm sure will cost at least 10x to 20x more than a replacement eBay FMIC.

 

Yes indeed, that's what I meant when I said I'd be thoroughly cleaning everything. 

Custard Contributor

Custard

Posted
  • Author
Posted
1 hour ago, KiwiRS4T said:

Next time just pull the outlet pipe off the turbo and pressurize from there on.

Mmm yes, I will be doing that in the future.

1 hour ago, STATUS said:

dont bother with r34 turbo they are still useless and prone to failure.

Save up and steel wheel what you have.

 

Sorry but I'm not here for upgrade advice, I know what my options are and I can't afford to do anything else. I will be spending under $200 on a replacement turbo and getting my (only) car back on the road ASAP. Not interested in people casually telling me to drop thousands on my car. 

admS15 Grand Master

admS15

Posted
Posted

Steel wheel high flow will cost you $850 and will turn your broken turbo into a brand new turbo with warranty and potential for decent power down the track if you decided to go that way. Just some food for thought.


Custard Contributor

Custard

Posted
  • Author
Posted
1 minute ago, admS15 said:

Steel wheel high flow will cost you $850 and will turn your broken turbo into a brand new turbo with warranty and potential for decent power down the track if you decided to go that way. Just some food for thought.

 

As far as I am aware it is not safe to be running a highflow turbo without supporting mods and a tune. which is where it gets expensive. 

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

Run a highflow with the stock actuator and completely remove the factory electronic bleed valve which will give you at most 0.5bar of boost.

Wise words from STATUS.. he happens to be one of Australia's tuners.

Anyhow, I still vote you replace your FMIC.. bits of metal in there could end up in your motor and cost you thousands instead of $150.

Custard Contributor

Custard

Posted
  • Author
Posted
42 minutes ago, Dose Pipe Sutututu said:

Run a highflow with the stock actuator and completely remove the factory electronic bleed valve which will give you at most 0.5bar of boost.

Wise words from STATUS.. he happens to be one of Australia's tuners.

Anyhow, I still vote you replace your FMIC.. bits of metal in there could end up in your motor and cost you thousands instead of $150.

Yeah, still a lot of money to half-arse it. If I upgrade I'm going to do it properly. Don't doubt that it's sound advice but again, not interested in upgrade advice, I can't bloody afford it, so please stop.

I found a small leak in my FMIC from some recent wallaby damage that my car incurred, so I will most likely be replacing it. Unfortunately for me it is not a $150 part, it's a $330 part. More f**king money down the drain.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

$330?

come on, cooling pro $186 delivered, gpi ones even less. 

nothing half arsed with a high flow with stock ecu at less than stock boost.

up to you, but you seem like a stubborn person so not sure why you're even asking for advice. 

put it another stock turbo so it blows up again, waste of time and money

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

    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      Maf is a question mark but TPS  I have set at 0.47, the fact that I’m getting proper voltage range out of it with the key on leads me to believe it’s functioning properly. I’m getting proper voltages on basically everything. I still need to look up voltage ranges for z32 maf and test that 
    • 25zenki
      S1 rb25/s14 starting problem

      By 25zenki · Posted

      Honestly no not at all, but it’s a very basic tune, it’s stock injectors q45 tps and z32 maf. Other than that it’s a completely stock base map. The file is from nistune and from my understanding if it was tune related I would be able to unplug maf and tps and it would still start even if it was a really shitty start. I have tried starting it with coolant temp, maf, and tps unplugged none of those 3 togethor or individually changes anything 
    • Matt Z
      SAU NSW - Bathurst Run 2025

      By Matt Z · Posted

      🏆 Skyline Supremacy Meets Mount Panorama Magic 🏆 Join SAU NSW as we take the long way to Bathurst, the home of GTR greatness. Saturday 30th August 2025 7:00AM Meeting Hanna Park North Richmond 7:30AM Departure Cruise Via Bells of Line Road 9:00AM Arrival to Stop 1: Golden Poplars Meadow Flat 9:45AM Arrival to Final Destination: Mount Panorama Motor Racing Circuit Meet Location: Hanna Park North Richmond Stop 1: Golden Poplars Meadow Flat Final Destination: Mount Panorama Motor Racing Circuit   *Disclaimer* There will be a lead and follow car so no one should get lost. If you would like to attend or bring others along please put your name down and a +1 as numbers will be needed prior! This is NOT a race and we will all be adhering to all road rules. If this is what you want please come to one of our many track days. This is an official SAU:NSW event and will be run under a CAMS permit. One of the things that really sets our club apart is our commitment to being true enthusiasts. When on normal roads we strive to maintain good relations with the authorities as well as the public in general. When attending one of Skylines Australia NSW events please try to: • Be aware of surrounding environment and act accordingly. • Drive courteously on the state’s roads as a true enthusiast should. • Understand how important it is to maintain the good name of SAU NSW and thus, treat others accordingly. • Any misbehavior will not be tolerated and you will be asked to leave.
    • soviet_merlin
      My BMW E39 528i touring

      By soviet_merlin · Posted

      What does it look like with highway driving? And yes, I had a similar thought as Duncan. It looks quite similar in my Stagea and I have made myself accept it as normal. Might have to look into it some day   Highway gets as low as 10l/100km on my end so I'm not as worried about it being a mechanical issue. More likely just the tune on the haltech.
    • OST Micah
      RH9 R32 GTR Build Thread

      By OST Micah · Posted

      While I was waiting for the new parts to come in for the charge pipe and radiator I decided to do some turbo modification. The drive pressure (exhaust backpressure) was a lot higher that I thought it should be. For 32lbs of boost drive was 55lbs. The turbine housing is a 1.10AR and my turbo builder has suggested to go to a 1.25AR. To test if a larger AR would do anything to reduce drive pressure AND not spend any money I decided to hog out the divider in my current housing. I removed it from the inlet and the whole way through the housing.  After reassembly and testing it doesn't look like this modification did anything for reducing drive pressure or requiring more fuel (making more power). Oh well, it was worth a shot. We'll get some data at the track if it makes it past the 60ft. I also machined a $7 shift knob off Amazon to fit my Stillway shifter since I didn't like the Stillway shift knob. Next on the list was the radiator replacement and fabrication of a new intercooler tube that had no silicon coupler. No pictures of this - I was short on time each night after work to get this done and didn't stop to take pictures.  Next was to get the clutch disks out and replaced. Previously when installing the dogbox I had ordered a set of the same sintered iron disks I had been running because I switched to the 26-spline input shaft. I thought it was odd that they didn't have any markings or brand name on them like all my old disks had but installed them anyway. At the track I could not get the clutch to lock up using my normal strategies. After two track nights I reached out to the clutch manufacturer and ask their thoughts. They said they had to switch the material out because they were having trouble getting the original material and that this new material would not take to being slipped very well.  So out with the first set of 26-spline disks and in with the correct material 26-spline disks. While I had the trans out I added an inspection/service hole. I've wanted one of these for a while. Now I can have a look at things and change the front cover shimming when needed (clutch wear). I hustled and got the clutch change done in a few hours on a Saturday. Hopped in the car and drove home. On the way home I did a 1-3 pull. When shifting from 2nd to 3rd the core plug in the back of the cylinder head popped out and dumped all the coolant. Thankfully I was only 30 seconds from home and coasted it there. Datalog showed nothing unusual and 2.5psi of coolant pressure. That plug has been in there since 1992 but I guess it worked its way out. Pulled the trans AGAIN and replaced the plug, JB welded it in, and made a brace. Also deleted the head drain I had added in during the bearing issue fiasco.  I am currently changing my boost control plumbing to make it cleaner. After that is done I'll make another attempt at getting past the 60.
×
×
  • Create New...