BNR34 RB26DETT Knocking sound

[CDGuy]

... it's coming from the block of my buddies car.

He's a member on here, but he's rather busy with school, and I'm worried for his car. It might be timing, sure, but I'm worried of imminent engine failure for him.

Any suggestions on what he should check/do??

I hear it's rather common in BNR34 engines. Not to mention, his is from a V-Spec, and it runs on rather low boost, so he's careful... which makes me rather worried as to what could have caused this.

So anyone that can help, please do, and I'll give all the help I can, and hopefully he'll find out about this thread.

Regards,

Steve.

[mcfly]

what kind of knocking noise.

head, injectors, rod knock?

[NismoS-tune]

Really, if it was such a big deal or if he was worried, he'd take care of it himself. I know I would. Maybe it's simply injector noise... Get a video clip.

[Kras]

deep knock thats consistent in speed - main bearing
knock that happens in rapid succession and with varying engine rpms - rod knock
hollow clatter near top of engine - piston pin/piston slap
ticking noise from head area - excessive valve lash, injectors, wrong valve shim/spit valve shim out, exhaust manifold leak

sorry if my descriptions suck, it's easier when i can hear the car in person

EDIT: if it's the factory ECU it shouldn't be detonation... if it senses det it will retard ignition timing to the point that the car will barely run lol

[Skym]

Heard a similar sound before on R34 RB26 from a V-spec. It sounded like a hammer hitting metal sound from bottomend. I think it was main or conrod bearing no 6 that disappeared (wasn't there) when engine was removed, sump removed.

[CDGuy]

Sorry for the late response.

Of course, he is enjoying a nice weekend with his family, as well as being filled to the max with schoolwork, that he's in over his head with. I do this for him, because he's a good guy. For past reference, his username is GTRJames30.

I just don't want him to have to face it alone, you know? In case a rebuild is possible, or whatever. I want to help him in anyway possible, so I made this thread knowing he wouldn't have time himself to do so.

Here is some video I got of the car, maybe it can come in handy... But I doubt it.

(And yes, his car set off the alarm of a nearby Jeep Liberty lol).

[YOUTUBE]tMmhafvJKas[/YOUTUBE]

Kras was a big help, because this is exactly what it is:

"knock that happens in rapid succession and with varying engine rpms - rod knock"

He thinks it's timing, but I'm more worried for something deadly.

As you can see, he doesn't push it too hard at all, he takes care of it well.

[mcfly]

maybe it is my speakers but i cannot hear anything wrong with the engine.

does it knock free revving at all?

Rod knock is not a sporadic, you either have it or you don't when the engine revs. The worse your bearing issues are the worse the knock is. Get a clip of the engine just free revving hood up.

[CDGuy]

Sure, I can try and get that. No, it's not spurratic, it happens all the time, and increase in velocity and repetition as the revs build.

[NismoS-tune]

Sounds like a regular stock gtr. Unless you get something with better sound, I'd say it's just paranoia...

[Shadao]

if it had rod nock i would have heard it... lol

my first car had rod nock so bad that one day my engine blew... lol gotta love those 4cyl mustangs... rod nock is so noticeable it sounds like you have put a bunch of ball bearings inside a metal drum then you beat on the drum while it falls down a flight of stairs... its VERY loud and VERY notice able...

[GTRjames30]

well i just saw this thread now...thanks alot steve for making this! as steve said im very busy so i havent had time to start anything. My knowledge isnt very strong in engines either so ive been trying to figure whats wrong with it for awhile now. I think it might just be the ticking noise from the head like what Kras said but it is hard to hear with most digital cameras. it ticks at the same rate as the rmps and is coming from somewhere near the back of the head(could be wrong with the location). i dont have close to enough money for a rebuild or even a removal either:s. ill try to get a good sound clip before i put the car to bed for the winter...cant afford insurance anymore but thanks for all the great info

[NismoS-tune]

I'm guess it's just injector noise and you're maybe paranoid. Just enjoy it as it is. It's 20 years old. If it breaks, fix it. Send a clip that may sound more but thus far, it sounds like a regular underpowered stock RB26...


Edit: Sorry, took it back, it was late in the night after a some strong beers.

[CDGuy]

... That was probably the most unfriendly post I've ever read from you Nismo. Might I also add, his car is not stock, it's been tuned quite well.

[DarkCaporaL]

Hope everything is alright James.

Post up a video from the engine bay, might help a bit. I could also come see you and take a look at it real quick. Should be able to see right away if it sounds right or not (PM me if you want).

Oh and it's a Nismo Omori tuned engine btw.

[CDGuy]

Hope everything is alright James.

Post up a video from the engine bay, might help a bit. I could also come see you and take a look at it real quick. Should be able to see right away if it sounds right or not (PM me if you want).

Oh and it's a Nismo Omori tuned engine btw.

.... Why did you have to say the last part? I'm the one who told him it was, he thought the logo was just a sticker ha! I didn't know if he'd want to keep it secret or not.

I'm pretty sure it's not a major tuned engine, just ports, cams, crank, gaskets, and turbo's. I know the cam cover would be a marble red finish if it was a fully done up engine, but it's not. Therefore it can't be fully done over.

I know the output of his car is over 420, and with the proper injectors and tune, as well as a raise in boost, it could be over 500... he's been really careful with it, and I even know the original owner in Japan, a man who used it every weekend to rip around on the Wangan with packs of other GT-R's.

So there you go James, your cars history is all over the boards!

Hahahaha.