Jump to content
SAU Community

Recommended Posts

Discovered an air leak in the rear throttle body. Initially presented as high pitched squeal at idle that immediately goes when you crack the throttle. Doesn't appear to be gasket related and a fine shot of petrol at the shaft end makes it run rough.

Suspect the TBs got washed when the head was recoed, apparently that will remove whatever compound Nissan uses during assembly. Hi Octane recommend a Tomei paste (wasabe and moly?) that is applied to the shaft ends on the inside of the TB and according to them to the butterfly also (not sure how this would help unless it's just to the sides of the butterfly to assist in penetrating the shaft space). Of course instructions are in Jap.

Wondering if any one has used it and if so can please advise how it works and how it should be applied.

Thanks in advance

Link to comment
https://www.sau.com.au/forums/topic/312302-rb26-throttle-shaft-leak/
Share on other sites

Ive had that before on my R33 gtr. I pressure tested the intake system and found that the leak was only under vacuum, and oddly it would seal up under a positive manifold pressure and hold a positive pressure once disconnected from the air compressor.

I solved the problem by spraying the ends of the shafts with a little INOX a few times when it was idling. No disassembly required. A little of the lubricant will have been drawn in to wet the seal. This made the noise stop. It may have also made the seal swell a little too. That was over 3 years ago, and the seals are still holding. (I stil see and occasionally work on the car).

The ideal approach would be to replace the seals and re-furb the throttles, or swap them with some from another car. Its a lucky guess as to weather you get a good throttle though. Getting the seals is the next issue. They cant be sourced from anywhere.

Having just dealt with this issue I can recommend this product-

http://www.xs-engineering.com/xsstore/pc/s...tle+shaft+seals

The website doesn't work properly when ordering (can't place an order) and you can't phone the place (in the states, you get a machine)) but if you email them through the store email you'll get a reply, took about 2 weeks delivered all up and around 130 AUD. You also get to take your plenum and throttle bodies off which is lots of fun. I also have 4 good condition second hand stock seals available if needed.

Sorry the pic is a bit useless

post-48345-1268904583_thumb.jpg

Thanks guys,

GTRNUR sounds exactly like mine. doo-doo I saw them when googling a solution, know Nissan have nothing but I hoped a bearing place might. Did you try locally?

You betcha i tried- took the seals to a custom seal making place and every bearing shop with no luck. Rang EFI in vic but no luck- you can probably find a seal that's close but you'd need to modify stuff.... I put the plenum and throttle bodies on a pressure testing jig I'd set up and ran 30psi with the standard seals (2 popped out) and then the XS seals (no leaks) They do have a spring in the inner lip but it's still a twin lip for both vac and boost. the main issue i had with seal places was the minimum thickness they had off the shelf was 6mm and the stock seal is 3mm thick. i reckon the XS is worth it for the hassle it saves.

Update for those interested. The US place with the seals isn't communicating by email and the phone isn't working. Tomei paste turned out to be just moly.

Took oem seals out - those that didn't fall out once the nuts on the end of the shaft were removed. Seals were in pretty poor shape and well pushed out note they are 2.7mm thick so not much room to move anyway. Found some double lip seals OS 10173 that are similar to the oem ones but about 1mm smaller OD. They look like the ones the evo boys use to correct the issues they have with boost leaks.

Pulled out the oem bearing retainers and replaced them with some new ones to suit the new seals, but with a small retaining lip. All bottoned up again and it runs fine. Recommend anyone who has their tb's off look at doing this, just check out the state of the oem seals and how far they are pushed out particularly if you're running higher boost. I upped mine to only 18 psi and they got bent out of shape.

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

    • See if you can thermal epoxy a heatsink or two onto it?
    • The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1780, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
    • Also, I logged some data from the ECU for each session (mostly oil pressures and various temps, but also speed, revs etc, can't believe I forgot accelerator position). The Ecutek data loads nicely to datazap, I got good data from sessions 2, 3 and 4: https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-2?log=0&data=7 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-3?log=0&data=6 https://datazap.me/u/duncanhandleyhgeconsultingcomau/250813-wakefield-session-4?log=0&data=6 Each session is cut into 3 files but loaded together, you can change between them in the top left. As the test sessions are mostly about the car, not me, I basically start by checking the oil pressure (good, or at least consistent all day). These have an electrically controlled oil pump which targets 25psi(!) at low load and 50 at high. I'm running a much thicker oil than recommended by nissan (they said 0w20, I'm running 10w40) so its a little higher. The main thing is that it doesn't drop too far, eg in the long left hand fish hook, or under brakes so I know I'm not getting oil surge. Good start. Then Oil and Coolant temp, plus intercooler and intake temps, like this: Keeping in mind ambient was about 5o at session 2, I'd say the oil temp is good. The coolant temp as OK but a big worry for hot days (it was getting to 110 back in Feb when it was 35o) so I need to keep addressing that. The water to air intercooler is working totally backwards where we get 5o air in the intake, squish/warm it in the turbos (unknown temp) then run it through the intercoolers which are say 65o max in this case, then the result is 20o air into the engine......the day was too atypical to draw a conclusion on that I think, in the united states of freedom they do a lot of upsizing the intercooler and heat exchanger cores to get those temps down but they were OK this time. The other interesting (but not concerning) part for me was the turbo speed vs boost graph: I circled an example from the main straight. With the tune boost peaks at around 18psi but it deliberately drops to about 14psi at redline because the turbos are tiny - they choke at high revs and just create more heat than power if you run them hard all the way. But you can also see the turbo speed at the same time; it raises from about 180,000rpm to 210,000rpm which the boost falls....imagine the turbine speed if they held 18psi to redline. The wastegates are electrically controlled so there is a heap of logic about boost target, actual boost, delta etc etc but it all seems to work well
×
×
  • Create New...