Rb26 Nasty Knocking

[GTRSOL]

Hi guys,

Last night i went out for a run in the 32gtr Launched in first. then boosted up to 180,

as soon as i let off a loud ticking/pinging sound was coming out from the engine,

I turned it off at a mates and let it cool down, started back up but only made the sound when free reving above 3000 RPM

Took off to take it home and under load it wouldnt make the sound or backing off, only when in between load and off load if that makes sense (cruising), by the time i got home the ticking/knocking had worsened and was doing it at idle.

any ideas? i'h hoping its not a big end as it sound like is coming from the top? (car still drives/boosts and revs fine.

Regards Jimmi

[SargeRX8]

It could be anything. I'm going to say noisy lifters. If you had a big end spun, you would know. It would sound more like a hammer on your block. If its a light tap, knocking sound, its probably head related. I'd put some new oil in it and see what it does. If the problem gets worse, louder, constant etc it may well and truly be a big end or some other thing at the bottom.

[Dajae]

I experienced the exact same sound about 4 weeks ago. Turns out i spun no.5 bearing. Fairly similar situation too, mine was caused by oil starvation.. Not good.

Hopefully you have better luck than i did. Take it to a mechanic, or get one to come to you..

Best of luck mate.

[GTRSOL]

Gets worse as it gets hotter so im expecting bearing,

Get it in hopefully tues/wed, thanks for your input guys.

[Adriano]

Bearing for sure, hope your mate only lives at the other end of the drag strip.

[Dajae]

Damn, sorry to hear mate.

Now you have an excuse for forged goodness

Ty.

[SargeRX8]

What do you suspect caused it? How old is the motor?

[GTR_JOEY]

id say the luanch then full throttle all the way to 180 is pretty much a give away that the cause of the problem was oil starvation

What i wanna know is

-what power are u running?

-what engine mods do u have and do u run a baffle or modified sump?

-do you overfill your sump?

[SargeRX8]

So that push from 0 - 180 is enough to starve the engine and flood the head with oil? What the f**k, that is insane.

[GTRSOL]

Hi guys,

Car is a Late 1993,

Power FC

Twin Nismo t28's

Tune

Standard Injectors,

Running 17psi At the time

Standard Sump not overfilled.

Air Temp at the time roughly 18-20 C

Roughly 355rwhp

Oh and 72,000kms,

Edited February 5, 2012 by GTRSOL

[Dajae]

So that push from 0 - 180 is enough to starve the engine and flood the head with oil? What the f**k, that is insane.

If the oil level is below optimum, then yes.

[GTR_JOEY]

Did i say that the head flooded with oil?

how would the head flood with oil if the oil pick up isnt picking any up

If you are pulling hard G's for an exteneded period of time, which is entirly possible in a GTR that performs a hard launch then is full throttle all the way to 180kms, then you can starve the engine of oil as the oil is not near the pick up...

insane?.. i think not

[GTRSOL]

If the oil level is below optimum, then yes.

Damn, i check the levels every week, changed the oil changed 2000kms ago used Castrol Edge

[Dajae]

Then perhaps it was just wear and tear on the engine. 20 year old engine is bound to have some weak spots..

Perhaps just bad luck. But oil starvation is a common problem with RB's.

[GTR_JOEY]

generally people put the extra oil in to get the sump up to 6L, because yes oil starvation is a common problem when pulling some decent G'samong other things

Edited February 5, 2012 by GTR_JOEY

[GTRSOL]

Yea and from what i know the engine has never even been pulled apart.

Anyway going in early next week so will let you know the outcome.

Cheers Guys.

[SargeRX8]

Did i say that the head flooded with oil?

how would the head flood with oil if the oil pick up isnt picking any up

If you are pulling hard G's for an exteneded period of time, which is entirly possible in a GTR that performs a hard launch then is full throttle all the way to 180kms, then you can starve the engine of oil as the oil is not near the pick up...

insane?.. i think not

I wasn't going against what you said, I just assumed you were probably implying that any useable oil would have been flooded into the head! Ive read that it doesn't take very long at all on some high rpm to fill the head up with pretty much all useable oil in the sump.

Pulling enough G's and maintaining that in a straight line to starve the engine of oil.... that is crazy shit insane! Its amazing to see these oil control issues evident in skylines. They are all very possible situations and you would think Nissan would have thought of ways to prevent this stuff from happening.

Also those KM readings, 72000km.......................................................................................................................... nah.

Is it a bad thing to overfill your sump? It takes me some good time to fill up my car and get it exactly on the right mark on the dip stick. I over filled it once and I let some oil out because I read it can do bad things but I didn't see how or why...

Edited February 5, 2012 by SargeRX8

[bish33]

sorry to hear mate

so is it a good idea to overfill 26's with oil??

[MrStabby]

Did i say that the head flooded with oil?

how would the head flood with oil if the oil pick up isnt picking any up

If you are pulling hard G's for an exteneded period of time, which is entirly possible in a GTR that performs a hard launch then is full throttle all the way to 180kms, then you can starve the engine of oil as the oil is not near the pick up...

insane?.. i think not

So, if the oil is not in the sump, where is it?

How the could the head flood with oil? I would have though it was obvious that this would happen before the sump is empty.

[MrStabby]

sorry to hear mate

so is it a good idea to overfill 26's with oil??

Yes. For track work, many fill the the bottom of the top bump on the dipstick. So about a cm above the full of the hatched area.