Jump to content
SAU Community

Recommended Posts

Hey guys.I had my R33 with power fc and basic mods tuned about 25000klms ago.Everything was fine for this time.I had my 100000km service done last week and ever since i get pretty high knock reading on both normal driving and when i give it a bootfull.The engine feels and sounds better than it ever has before.When giving it a bootfull it will read between 70 and 100 on the knock reading every time and when driving around normal i will get readings of up to 50.Can any one enlighten me as to what may be wrong please.This car is my daily and i have to travel about 90kms a day so i dont want to damage it!

Link to comment
https://www.sau.com.au/forums/topic/288280-high-knock-after-service/
Share on other sites

You'll lunch it if you don't baby it, need to get it back to the shop and get it re tuned. Anything over 60 is a worry, and 100+ is piston melting time.

Could be something simple like a fuel pump on the way out?

You'll lunch it if you don't baby it, need to get it back to the shop and get it re tuned. Anything over 60 is a worry, and 100+ is piston melting time.

Could be something simple like a fuel pump on the way out?

Can't really afford to lunch it.Fuel pump is a walbro 6 months old :D

did they set the timing for you in the service. could have been slightly retarded when originally tuned

Don't know mate.I rang the workshop and he called my tuner Matt Spry who said to bring it down it wont take long to fix but when i called him to make a time he was pretty busy and didnt know when he could fit me in :D

Please drive like miss daisy till the tune/timing is sorted............................

I'll do my best mate.I'm pretty worried about it.I didn't know this could happen after a timing belt change

I'll do my best mate.I'm pretty worried about it.I didn't know this could happen after a timing belt change

let it blow!!!....then maybe you can stick a 2lt S20 in it!!!!....take it closer to the original GTR....know what I mean???

Edited by Jetwreck
I didn't know that changing the timing belt could affect the timing. Does anyone know the truth ?

yep it will, as the cas gets removed. I'd say it was either not set after re-assembly, or the most likely case is the base idle was set wrong before it was tuned (say 10degrees) and after they serviced it they set it properley to 20 and it now has 10 degrees more base in it.

Edited by URAS
yep it will, as the cas gets removed. I'd say it was either not set after re-assembly, or the most likely case is the base idle was set wrong before it was tuned (say 10degrees) and after they serviced it they set it properley to 20 and it now has 10 degrees more base in it.

thanks Trent,

If the person changing your cam belt marked the cas and put it back in exactly the same position your timing will still be out bacasue of the new belt. 'Tell your tuner that your cambelt has been changed and you probably just need 5min of his time to check the base timing - not a 2 hour tune, and he should be able to fit you in (if not get another tuner).

I know it might be what trent said with the cas but has anyone thought about the mechanic taking the car for a testdrive; thrashing it for an hour n filling the tank back up with regular 91 octane fuel? thats why its knocking so bad.

plausible as if u only had quarter tank n he used most of it, refilled with 91octane and cos ur car is tuned for 98, its knocking.

jst a thought!

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

    • Driveability will be about the same with either externally venting BOV, or no BOV at all. Perhaps worse one way than the other, with me thinking that the definitely more flow going through the AFM through a venting BOV more likely to cause rich stalls than the perhaps more flow that the AFM might read on reversion. There is no such thing as "turbo damage" from not having a BOV at stock, or even quite a lot higher than stock, power levels. You need a big turbo with a lot of mass spinning hard getting a horrible slowdown from a slammed shut throttle before there is anything like the shaft loads required to damage things. Not an issue on small turbos. The ONLY 2 reasons that Nissan put a recirc valve onto the RB were: It is a bypass valve. It is open when under vacuum. When not on boost, it bypasses intake air forward around the compressor, which unloads the compressor, allowing the turbine to sping more freely, making the whole lot a bit more efficient when just puddling around. Throttle response should also be faster via the shorter, smaller diameter BOV pipe (when in NA, ie before the BOV closes and boost is building) which is nicer for driveability. Emissions. The reversion causes CO pulses. Eliminate the reversion (or at least, keep it away from the AFM) and you don't get that. The stalling/driveability aspect could have been tuned around, as shown one example of by dose above, if Nissan hadn't put a recirc valve on. Many many turbo engines before the RB had no BOV. They did not stall. See the RB30 turbo as an example. Nistune is definitely better than just stock ECU. It allows you to access and change things that are not excellent on the stock setup, and allows you to do mods like put decent injectors in, relocate the AFM, put a bigger turbo or even cams, etc, on, change to coil swith completely different swell needs, etc etc. All the things that you might need or want to do 25 years after the car was new. Aftermarket replacement ECU is obviously better again, because it gives you even more freedom from the constraints of the stock ECU. I won't be needing to go any further than Nistune though, for the new turbo in the 250ish rwkW region I'm going to, with big injectors, and most other things being stockish.
    • Lucky the prp block is supposed to be released next weekend 
    • Wow guys thank you very much for the HUGE info :-) @GTSBoy I have like 30 minutes if test drive with that car/engine and it not stalled once. IMO it ran very smooth so i guess it was not that bad(but asi i said it is stock) That atmo BoV is worse than no BoV or in my case or it is/will be the same? Cuz frankly i rather have little whooosh sound than that sututu 😄 But either way the less harmfull for engine/turbo the better(if the stock is not an option right away) Yeah about that rebuild i talk with guy who will be doing swap and custom pipes...i think i can get stock BoV or get aftermarket which will function the same. Yeah i looked at that R35 option and i try ask my mechanic more about that if he knows. The engine has stock ECU but i can get Nistune for it. On that stock it runs quite well...but i have limited time with it so rly dont know. Ecumaster is this https://www.ecumaster.com/  It is not some dodgy backyard ECU :-)  @MBS206 Yeah but it will be better to have Nistune than the completely stock ECU no? About that "same" atmo/no BoV. The drivebility would be the same? I dont know but i kinda guess that amto BoV would cause more problems than no BoV in my case? Or is the same? You just "change" one sound for the other? Yeah i read many many many topic about hurting the turbo. But no one know anybody that would 100% tell that his turbo/engine blows/get damaged by not running BoV. Of course turbo would be little happier IMO if it has BoV ..but if you do not trash i think i should be good. And as you can see iam already trying to get this right...just working what i have right now :-) Yeah iam kinda the same...i dont want nothing loud and frankly iam not liking that sututu noise that much 😄 i rather have little bit of "whooosh" or no sound at all. Of course in my case it si a completely another world when you came tu Turbo car with open air box and no BoV and you driving the N/A ...all i hear is engine. Here? I heard turbo/sucking and that sututu 😄 @Yeetus So in my case it is really no difference to run no BoV or some atmo BoV like GReddy FV2? The car would drive the same and has "the same" little problems? As i wrote above i kinda thinked that atmo BoV with stock MAF would cause more problems...but then again i dont know much about no BoV either :-)  So to avoid stalling i "cant" just put neutral on stop lights like from higher rpm? Or? Yeah iam already looking for ECU :-)  Yes iam at the same side with thar R35 MAF :-)  @Dose Pipe Sutututu Thank you i (my mechanic/tuner) will look into that) Guess iam taking the Nistune at least :-) 
    • Here's the workaround with Nistune I was talking about, just add in more timing on the decel table And play around with the fuel cut & recovery, it's enough to stop it from stalling on a decel  
    • Hi Apex and welcome! 
×
×
  • Create New...