Jump to content
SAU Community

Rb26 Engine Noise Help.

gtmatt

By gtmatt,
in Engines & Forced Induction

 Share

Recommended Posts

gtmatt Apprentice

gtmatt

Posted
Posted

Hi, firstly can i say congrats to administrators for giving people like me access to such a great resouce such as this forum.

righto to the problem.

The rb26 in my r32 gtr has developed a knocking noise starting at 2200-2400RPM and increases in noise intensity to 3000RPM.

At idle the engine there is no miss, no noise showing no sign of a fault.

I have changed oil, pulled out the cams, compressed each valve individually and put it all back together to eliminate any issues with cam timing however the noise is still there.

The noise was first noticed after doing several 1/4 mile runs on the g-tec. I had a wideband installed during the runs to ensure mixtures were ok as the engine had been rebuilt about 2000km's before (by myself). The turbo's were running standard boost. There was no noticable noise to indicate a failure, the noise was only noticed when i left to go home.

the noise is a solid noise at 3000 almost sounds like it is in the inlet side of the head.

I havent yet changed the cam timing to ensure it is not valve knock. The engine turns over by hand fine with no noticable issues. On inspection of the cams there was no noticible sign of an issue, aside from a wear mark on no 6 exhaust base circle but checked clearances and was fine.

i have heard big end knock before (the reason for the rebuild) and i dont believe it is the issue.

The list of mods for stage one

- JE forged pistons,

- ARGO rods with arp bolts,

- Jun oil pump,

- Calico coated main and big end bearings,

- Tomeii cams type B and valve springs,

- Tomeii head and manifold gasket set,

- Aftermarket split dumps,

- Garrett GT2560 turb's

- new r33 crank

- head oil restrictor

- tomeii sump baffle

- modded oil return line to sump

- turbo blankets and manifolds heat wraped

- Ross Harmonic balancer

- ARP head and mains studs and bolts

if anyone has come across this issue before and knows what it may be can you please enlighten me as it has me puzzled mostly due to the inconsistancy of starting at 2200 ie a valve knock would be heard at idle, so too would a big end failure. I am maybe thinking it might be an issue with a peice of ancillary equipement on the engine - not explored.

thankyou for any future help.

Link to comment
https://www.sau.com.au/forums/topic/259147-rb26-engine-noise-help/
Share on other sites
gtmatt Apprentice

gtmatt

Posted
  • Author
Posted
I have an R32 GTR which had a knock about two years ago, at 2000--3500 RPM It sounded pretty bad but hard to believe, turned out to be only the cam belt bearings. Just a thought.

Thanks, when you say cam belt bearings, do you mean the cam belt tensioners, i never thought of them being an issue because they are new, but doesnt mean they havent failed i will check it out thanks.

N1GTR Grand Master

N1GTR

Posted
Posted

Blown gasket.

Mine did that last week, the sound was a strange one and sounded like a few other things that have gone bang on my gtr over time, but as soon as it was looked at by the shop they saw the carbon buildup around the front turbo manifold and then it became clear. I couldnt see it cause it happened at night

Its probably not, but doesnt hurt to check and rule out that possibility :D

gtmatt Apprentice

gtmatt

Posted
  • Author
Posted
Blown gasket.

Mine did that last week, the sound was a strange one and sounded like a few other things that have gone bang on my gtr over time, but as soon as it was looked at by the shop they saw the carbon buildup around the front turbo manifold and then it became clear. I couldnt see it cause it happened at night

Its probably not, but doesnt hurt to check and rule out that possibility :D

thanks its on the list of things to do :(

gtmatt Apprentice

gtmatt

Posted
  • Author
Posted
possibly dropped a valve guide?!?

its a really common problem with rb26 and i see in your mod list they have not been replaced...

yeah your right i think a head pull is the next step :) i was trying to avoid it (hence the post and if anything else might be the prob) but have pulled it down as far as having cams out and didnt find anything that was likely to be the issue but because it was so over a year ago that it happened i put it back together to relearn the noise etc, and also rule out some of the simple things.

thanks for the advice :P

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 seem to the be only person that is using a Haltech 2500 on an NA motor, I've installed a Bosch DBW throttle body to the OEM intake manifold and am having problems maintaining AFR even with the wideband o2.  It will run extremely rich at idle and up to redline, but under load it will go extremely lean in the 20s and i'm essentially having to rev it over 4k and feather the clutch to get it up to speed.  I've read a few other threads of about the butterfly, it seems removing the vacuum to it is supposed to have it remain open, i've noticed no difference under 4k with the vacuum line to it plugged.  I'm hoping someone here has had luck using the NA manifold with Haltech, and if they happen to have a tune for it.  
    • sonicii
      Could it really happen......

      By sonicii · Posted

      I don't know any details, but I really wouldn't be surprised if they do it as a LHD only version, at least initially.
    • Gareth87
      What should I do next to hold the head on

      By Gareth87 · Posted

      Thanks for the replies everyone. Definitely a coolant push. Oil catch can is empty and always has been. As the engine is out now I'll be having a good look over things. I do have some detonation on the piston tops from a trigger issue back about 5 years ago. I felt it and shut off then bought a new ecu and changed the trigger. Never been an issue since. It never hurt the power, its made almost 80hp more since that incident but I will pull the bearing caps to take a look. If the bearings are damaged I will do a bottom end refresh. Head is being re conditioned at the moment and the block will be cleaned and checked to ensure it's flat. I'll go with a kameari gasket and see how it ends up. The other thing I'm not super keen on is the cylinder colours. I suspect this is from the inlet manifold. The plan will be to put it back together, retune and then stick a plazmaman billet inlet on it and retune. I'm happy with the power, if it makes a little more, then great, but I would rather just make everything more efficient at this stage.
    • MBS206
      Could it really happen......

      By MBS206 · Posted

      Maybe they'll look to do a bunch of presales to help inject some cash fast for their financial issues...
    • MBS206
      R34 25GT Engine Light 21

      By MBS206 · Posted

      Does it also misfire equally when revving?   Josh is very correct in what you should do. The coilpack harness wiring loom itself is a known problem due to its age and the number of heat cycles it has gone through. Throwing parts at a vehicle to diagnose the issue isn't a smart or good way to do it. Secondly, you may have a bad coil pack, you pop replacements in, they fix that issue, but messing with the harness breaks it, so the issue persists. So now you think "well it wasn't the coil packs" and have to continue chasing your tail, potentially swapping back in your shit coil packs and returning the good ones (yes, I've seen people do this because 'it wasn't the problem' and they want to save money). And suddenly, you've got two issues with the same symptoms...   Diagnose, don't use the spare parts shotgun.
×
×
  • Create New...