Jump to content
SAU Community

Recommended Posts

Howdy All,

I'm literally racking my brains on this one and I wanted to reach out and see if anybody had any ideas.


I fitted RB26 throttle bodies/plenum to my RB25NEO. Started it up, it was fine appart from head gasket failure. So removed the engine, did the head gasket. Put it all back together and now it starts and runs nicely but has this really bloody annoying whine!!


- It's coming from underneath the back/middle of the plenum.

- It doesn't appear to be coming from any injector (disconnected each cylinder and noise doesn't go away)

- It's there irrespective of fuel pressure

- It's there irrespective of whether the plenum is on or off (im running map sensor, so will run without plenum fitted)

- It's there if I remove the balance box/aac value and bipass the balance pipe

- I have swapped out the throttle bodies for another set. Still there.

- If you move the steering wheel to put load on the PAS pump, no change in volume or tone

- If you pump the brake no change in volume or tone

- It's there if you press the clutch

- It's there if you put it in gear



- It disappears if you rev cylinders 5&6.

- It decreases but is still audable if you rev cylinders 1&2 or 3&4

- If you rev the car with the plenum on, it goes


See the two video's below





Any ideas??


What do you mean by started up and was fine, apart from head gasket failure? Did the head gasket just somehow fail while you put on a new inlet? did it make that noise before the head gasket was changed?

The coolant was full of gunk, which I can only presume was something similar to radweld. I dropped the coolant, did the work on the car, started it up and the engine was mixing oil/water. I can only presume that the chap who sold me the car knew about it and threw in the headstop/radweld to get shot of it. The plugs were loose in the engine too. Bit of a mess.

Anyway - I seem to have isolated the problem. The adaptor plate was leaking air through cyl 5., causing high idle and the stupid sound (I hope) The inlet port on number 5 was full of hylomar sealant, where as all others were clean. I'm in the process of cleaning everything up, then i'll reassemble.

Fingers crossed and thanks for your help.

Chris

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

    • GTSBoy on your suggestion on another thread I had a look at those injectors and ended up getting them because of the quality.  Got the expensive ones.  
    • Hey guys been looking everywhere to try and find the correct gtr hood latch support part number but only found the first half and when I search with that number it sends me to an r34. The first part I found was 62515. If anyone could help me with the rest then I’d really appreciate it. Or if there’s some alternative hood latch support that would work even better cause I can’t find any for sale. (Searched on upgarage, partsouq,buyee,rhdjapan) 
    • If you've only done the upper control arms on the rear, AND you have changed their length (by more than about 1mm) to set the camber you want, then you will definitely need/want to install traction arms also. Adjusting the camber arms on their own WILL introduce bump steer and make the car unpleasant to drive. Most owners have no idea that their car could behave infinitely better than what they put up with. I'm not entirely sure what the Stageas need, but I am thinking that unless you have massive front spring rates and pretty soft rear springs, you have waaaay too much rear bar. Oversteer city, in my estimation. Combined with possible excessive bump steer from maladjusted arms, that could be a recipe for nastiness. ATR43SS2 is not a highflow. It is an outright replacement turbo. It's a little bit bigger than the largest highflow profile that Tao does. Probably a solid 300rwkW turbo where the bigger highflows will be about 30-40rwkW less. Nevertheless, we're only talking about ~300 rwkW, which is well within the abilities of the stock ECu to run with a Nistune on board. I would do so without hesitation - and I will be doing so when I get my finger out and actually get the injectors and AFM installed. But, if you would prefer to drop a whole lot more money on the ECU side, then I suspect you're looking at Haltech. The Haltech fanbois here will all spout on about all the available engine protection you can have, that you can't have with the Nistune option. And they're right. But it doesn't really come for free either. You will spend more money on extra sensors and the like, plus the work to install them. If the engine was built and therefore represented a big investment to protect, then I'd say definitely do it. If you view the current (and forever into the future) shortage of replacement engines as something to prompt similar protection, then also, do it. If you see a destroyed RB25 as an opportunity to put in a Mercedes or other V12 (like I kinda do)... then your perception of the risk/reward might differ. These are good injectors. You can also get a "better" set of the same with more flow matching, for more $$. 1000cc is where you will want to be. You will need an R35 AFM and adapter tube if you want to stay with Nistuned stock ECU. Otherwise, if going Haltech, you can ignore. As for intercooler. Just about anything will do. You're only talking about ~300rwkW. Just put a big core in there. Be aware that return flows do add significant pressure drop and will cost power and will make the turbo work harder to achieve the same goals. If you can manage a proper crossflow, do it. I'm keeping my very good return flow because I'm only expecting to be in the ~250rwkW range, and will live with whatever outcome I get.
    • I have a heap that i have collected if you want some authentic ones still. Pm me if your interested!
×
×
  • Create New...