Jump to content
SAU Community

Recommended Posts

Hi Guys,

I know its my forst post but i need some help.

I am hearing bit of a knocking noise coming from the top of my R33 GTR engine (turbo side) a few seconds after it starts. The noise kinda increases with revs but disappears after 3k rpm but returns when i let go of the gas. The knocking does go when oil get slightly warm after 3 or 4 minutes. I have also taken the oil cap off when the engine is on and i can hear a clicking/tapping kind of noise. The noise has got a bit louder over time but i am hoping its the clearances or lifters and nothing more than that.

Anyone have any suggestion or further dignostic help???

Gerry

Edited by Dr GTR
Link to comment
https://www.sau.com.au/forums/topic/166248-knocking-from-gtr-engine/
Share on other sites

Hi Guys,

I know its my forst post but i need some help.

I am hearing bit of a knocking noise coming from the top of my R33 GTR engine (turbo side) a few seconds after it starts. The noise kinda increases with revs but disappears after 3k rpm but returns when i let go of the gas. The knocking does go when oil get slightly warm after 3 or 4 minutes. I have also taken the oil cap off when the engine is on and i can hear a clicking/tapping kind of noise. The noise has got a bit louder over time but i am hoping its the clearances or lifters and nothing more than that.

Anyone have any suggestion or further dignostic help???

Gerry

are u sure the noise is comming from the top of the engine? not the middle or bottum?

I thought when my gtr was knocking it was coming from the top but it was actually bottum end bearing

Bent valve(s)!!

This happened to a customers GTR, previous owners tried to chase power with boost, leaned out which caused melting of plugs and broken ring-lands. The melting of the plugs caused material to get caught under both exhaust valves at no.6, something else could have gone through engine also?

If the valves dont seat then they have too much clearance and knock at top of engine.

G'luk

Thanks for your response guys....The bearings were only done about 3 months ago due to a dodgy filter so i am hoping that they havent gone again. When they did go the noise was not like this and the mechanic seems to think that the noise is my clearances thet need sorting. This time its kind of coming from the top and definately towards the middle of the exahust side cam but as i said the noise does go away after a few minutes.

Gerry

Edited by Dr GTR
whats the oil presure like? hot/cold? ive never ever heard a big end knock disapear with heat. maybe a dodgy lifter

The oil pressure is great due to the trust oil pump. Im seeing 7bar when the car is stone cold and just over 2 bar on idle when the oil reaches 80 degrees. Pressure whilst driving is also very good. I also have trust sump extension.

Gerry

Here is a sound clip io managed to get today when i started her.

Full spec of the car is as follows just in case it could be one of the mods

Apex V-max SPL pistons with cooling channles

Trust rods

R34 crank balanced

Nismo 24 U Block

Apexi 280degree cams with 10.5mm lift

Apexi double springs

Trust greddy Intake plenum

Greddy t517z trubos

Trust oil pump

As i mentioned, this noise does go after the oil starts warming up and there is no loss in performance thats for sure lol

CIMG0895.WAV

Edited by Dr GTR
Geez man - I wouldn't be running the engine - take it to a workshop !

Fingers crossed its nothing major man........My tuner is coming over in the morning to have a listen to it. If it was the bearings wouldnt the noise be permanent???

Gez

Edited by Dr GTR

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

    • Does that German restaurant still exist in the old place out the NW end of Goulburn? When I say "out the NW end of"...I am really being vague. It was 1997 when I was last there, and the only point of reference I can recall is that it was on the opposite side of the main drag from the big merino. And when I say "opposite side of the main drag", I don't mean "on the main drag". It was either a couple of streets back from there, or might have even been out in the sticks a bit further. Was an old farm building or mill or somesuch. And when I say "the big merino" I might actually be thinking of a completely different part of town, because I just looked on maps and the big bugger is not where I remembered him to be! The food was good, consisting largely of various German mystery-meat sausage/loaf things and kartofflen.
    • So while the second sentence is completely correct and the whole point of the conversation, the first sentence bears consideration. If this bloke is just hoping to throw big turbos on and drive it around, because there are no helpful facilities at all in his tropical paradise** then he likely has zero chance of even knowing what the TP is on the last column in the stock maps, let alone know whether the ECU is operating anywhere near it or past it. So the point is very very moot. And, per what I said before, at stock boost on those turbos, you may well be off the end of the map. **I'm just back from Vanuatu, so I know exactly what small Pacific nations can be like wrt paradise without requisite facilities. But it's not even that simple. I put a high flow on my car and had to drive it around with a proper tune because of the lack of opportunity*** to put the bigger AFM and injectors into it to allow it to be tuned. I had to turn the boost down to less than I had before, and back off the boost controller's ramp, because it was exploring parts of the map that it didn't drive in before, and really couldn't access for tuning on the dyno either, and so was pinging. It was still well within the last column, because when I first**** set up the Nistune on the Neo I rescaled all axes of the maps to give some more space to explore. ***Family dyno was broken ****This was 13 years ago, and the TIM thing wasn't a thing then and so TP would definitely grow when pushing past the stock tune's limits.
    • Yep, this bit another local owner. I caught it before putting the transmission back into the car, what I noticed was the pressure plate fingers weren't flat and even. It's more obvious with the pull style clutch because the throwout bearing ring was visibly not flat once everything is put together. Nismo should really update their instructions to call out this specific detail. I'm not even sure the clutch as-shipped orients everything properly.
    • It ended up being that orientation of the float hub in relation to the clutch disk, when I installed it, I heard a loud click and being stupid, I decided to not take it a part and check it. The hub didn't properly align with the clutch disk and was causing the issue. Definitely an odd one! Dahtone Racing was able to fix me right up, stand up blokes!      
    • Right, but I'm saying on the stock ECU measured airmass from the MAF is no higher than stock. So it's accounting for the higher flow rate iso-manifold pressure. You just have to keep turning down the boost until you're within the stock tune's load scale. If you run off the end there's no telling what will happen. This does mean there's zero benefit to the turbos you're running vs stock, if anything it's just a straight downgrade because the transient response is worse, you don't even get the ECU's boost solenoid helping to pull the wastegate closed during initial spool, and peak power is only whatever the factory map can give you before you hit the R&R corner. On a -9 I would bet that you would have to change out the wastegate spring once you have a real ECU and you're tuning it for real. I'm not saying this is a remotely ideal state of affairs, it's just a way to keep it driveable until you can get a proper tune done.
×
×
  • Create New...