Jump to content
SAU Community

Rb25 Exhaust Manifold Installed: 1 Bolt Hole Threaded

islade

By islade,
in Engines & Forced Induction

 Share

Recommended Posts

islade Rising Star

islade

Posted
Posted

Hey guys,

Just installed my new exhaust manifold. It's a stock one with external gate attached to it. Anyway, 11 studs are very happily installed. The one on the top row second from the rear somehow threaded out the hole it's supposed to go into. So i've installed it gently, but if i put any real pressure on it, it spins freely as i've obviously damaged the threads inside the hole.

If all 11 others are attached securely, am I going to be okay, or is this going to be exhaust leak central?

If it is a problem, how do i fix this?

Thanks,

Isaac

The Mafia Grand Master

The Mafia

Posted
Posted

Exhaust leak central

Where is the stripped hole? Go and get a helicoil kit, and repair it. Its piss easy to do. Just make sure you have a practice somewhere if you haven't done it before.

Also, you might even be able to do it where it is without taking the manifold off.

JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

aslong as both the manifold and head are straight and clean then it'll be fine, and given the top row is pretty easy to get to with a standard manifold anyway it cant hurt to see how it goes.

The Dan Grand Master

The Dan

Posted
Posted

aslong as both the manifold and head are straight and clean then it'll be fine, and given the top row is pretty easy to get to with a standard manifold anyway it cant hurt to see how it goes.

You can't be serious? It's going to leak no matter how flat both surfaces are. Not straight away, but eventually. Then it destroys a gasket, and other studs that cop the heat from it.

Do it once, do it properly. Helicoil as suggested above

JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

so all the hundreds of standard cars driving around with 3-4 studs fallen out with no leaks are miracles? its a thick cast iron manifold, its not gonna bend from 1 missing stud

The Dan Grand Master

The Dan

Posted
Posted

so all the hundreds of standard cars driving around with 3-4 studs fallen out with no leaks are miracles? its a thick cast iron manifold, its not gonna bend from 1 missing stud

Didn't say the manifold was going to bend. It's going to leak though. And the studs fallen out of hundreds of standard cars is because the gasket is leaking, causing the hot gases to pass over the stud. If he puts this all back together without fixing it while it's close, then it WILL leak, it's only a matter of time....and from what I have seen, no more than about 3 months depending on what he does with the car

islade Rising Star

islade

Posted
  • Author
Posted

Cool

I don't think it's worth "seeing how it goes" because the inconvenience of removing everything again overpowers the "pay some mobile dude $88 to come fix it for me tomorrow)

Words stupidest question, but with the studs, does the "long threaded end" or "short threaded end" go into the head?

JE-R33GTS-T Apprentice

JE-R33GTS-T

Posted
Posted (edited)

As for studs I had one stuck in with loctite from the previous owner haha no wonder the back two cylinders had no exhaust gasket left I pulled the stud out with my fingers

Edited by JE-R33GTS-T
JonnoHR31 Grand Master

JonnoHR31

Posted
Posted

Cool

I don't think it's worth "seeing how it goes" because the inconvenience of removing everything again overpowers the "pay some mobile dude $88 to come fix it for me tomorrow)

Words stupidest question, but with the studs, does the "long threaded end" or "short threaded end" go into the head?

short end goes into the head

Smegul Explorer

Smegul

Posted
Posted

You can't be serious? It's going to leak no matter how flat both surfaces are. Not straight away, but eventually. Then it destroys a gasket, and other studs that cop the heat from it.

Do it once, do it properly. Helicoil as suggested above

what? I have 2 broken studs and have never had a leaking problem???

89CAL Grand Master

89CAL

Posted
Posted

you'll probably find that the cars that have broken a stud over time may or may not have a leak due to being on the car for hundreds of hot/cold cylces were the gasket has bonded slightly to the head and manifold. It's a bit hit and miss, I had 1 broken stud and didnt have any exhaust leaks but others might not be so luc

89CAL Grand Master

89CAL

Posted
Posted (edited)

you'll probably find that the cars that have broken a stud over time may or may not have a leak due to being on the car for hundreds of hot/cold cylces were the gasket has bonded slightly to the head and manifold. It's a bit hit and miss, I had 1 broken stud and didnt have any exhaust leaks but others might not be so lucky.

With a new gasket as said above, this will not work as the gasket will leak pretty quickly

Edited by 89CAL

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

    • Haggerty
      RB25DE NEO with Haltech ECU

      By Haggerty · Posted

      I guess one thing that might be wrong is the manifold pressure.  It is a constant -5.9 and never moves even under 100% throttle and load.  I would expect it to atleast go to 0 correct?  It's doing this with the OEM MAP as well as the ECU vacuum sensor. When trying to tune the base map under load the crosshairs only climb vertically with RPM, but always in the -5.9 column.
    • CF.Panda
      R34 25GT Engine Light 21

      By CF.Panda · Posted

      AHHHH gotchaa, I'll do that once I am home again. I tried doing the harness with the multimeter but it seems the car needed a jump, there was no power when it was in the "ON" position. Not sure if I should use car battery jump starter or if its because the stuff that has been disconnect the car just does send power.
    • Haggerty
      RB25DE NEO with Haltech ECU

      By Haggerty · Posted

      As far as I can tell I have everything properly set in the Haltech software for engine size, injector data, all sensors seem to be reporting proper numbers.  If I change any injector details it doesnt run right.    Changing the base map is having the biggest change in response, im not sure how people are saying it doesnt really matter.  I'm guessing under normal conditions the ECU is able to self adjust and keep everything smooth.   Right now my best performance is happening by lowering the base map just enough to where the ECU us doing short term cut of about 45% to reach the target Lambda of 14.7.  That way when I start putting load on it still has high enough fuel map to not be so lean.  After 2500 rpm I raised the base map to what would be really rich at no load, but still helps with the lean spots on load.  I figure I don't have much reason to be above 2500rpm with no load.  When watching other videos it seems their target is reached much faster than mine.  Mine takes forever to adjust and reach the target. My next few days will be spent making sure timing is good, it was running fine before doing the ECU and DBW swap, but want to verify.  I'll also probably swap in the new injectors I bought as well as a walbro 255 pump.  
    • AnimalGarage
      spot the stagea

      By AnimalGarage · Posted

      It would be different if the sealant hadn't started to peel up with gaps in the glue about ~6cm and bigger in some areas. I would much prefer not having to do the work take them off the car . However, the filler the owner put in the roof rack mount cavities has shrunk and begun to crack on the rail delete panels. I cant trust that to hold off moisture ingress especially where I live. Not only that but I have faded paint on as well as on either side of these panels, so they would need to come off to give the roofline a proper respray. My goal is to get in there and put a healthy amount of epoxy instead of panel filler/bog and potentially skin with carbon fiber. I have 2 spare rolls from an old motorcycle fairing project from a few years back and I think it'd be a nice touch on a black stag.  I've seen some threads where people replace their roof rack delete with a welded in sheet metal part. But has anyone re-worked the roof rails themselves? It seems like there is a lot of volume there to add in some threads and maybe a keyway for a quick(er) release roof rack system. Not afraid to mill something out if I have to. It would be cool to have a cross bar only setup. That way I can keep the sleek roofline that would accept a couple bolts to gain back that extra utility  3D print some snazzy covers to hide the threaded section to be thorough and keep things covered when not using the rack. 
    • GTSBoy
      R34 Handbrake light saying ON and intermittently flashing

      By GTSBoy · Posted

      Probably not. A workshop grade scantool is my go to for proper Consult interrogation. Any workshop grade tool should do it. Just go to a workshop.
×
×
  • Create New...