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View Full Version : Possible Rod Knock - Now what?


MrFairlady
09-11-2009, 09:11 PM
So I've finally had my car running Great for the past 2-3days and and Hitting 15psi (ENTH tuned for) and now it has a Slight Knock at 3500rpm All of a sudden.Started as a slight tick earlier Today.

Planning to Pull it and just Rebuild bottom end w/ New/Upgraded parts.

What To Upgrade or upgrade w/ while its out.
Would like the car to be 300-350whp using my GT2860 w/ possible PFC in near future.

----A Must Yes??-----
Thicker/Lower compresson headgasket (Pwr Enterprises,etc)
ARP Rod Bolts
ARP headbolts

Do I need to do Wrist pins?
Upgrade Pistons, or Use New Swain coated OEM's??

any help would be great.

***Noise BTW is only after it warms up and does not show at idle,..after it warms up and you rev to 3000-4200 and its There but no higher.****

Sileighty_85
09-11-2009, 09:24 PM
Theres a differnce between a Knock and a Tick

Rod Knock will occur at ALL RPM range, when you rev it the Knock will get louder and faster, not just at certian RPM

Probably detonation or HLA's need to blead or low oil pressure

herbieS13
09-13-2009, 11:11 AM
if you rebuild get a stroker kit :) thats what i did and i made 350whp at 13 lbs on a 2871r

singlecamslam
09-13-2009, 11:17 AM
You dont need a stroker kit to make 350 HP. You can use stock parts.

S14_Kouki
09-13-2009, 11:24 AM
Theres a differnce between a Knock and a Tick

Rod Knock will occur at ALL RPM range, when you rev it the Knock will get louder and faster, not just at certian RPM

Probably detonation or HLA's need to blead or low oil pressure

YES YES YES

If you rebuild just get main,rod and thrust bearings new rings and seals

jr_ss
09-13-2009, 11:35 AM
Pull a spark plug to isolate the noise. If it goes away when one of the plugs is pulled, you found the cylinder it is located in. If you do this and it doesn't go away, it's in the head.

If it truely is a rod knock, it'll get louder and harder the higher you rev it.

S14_Kouki
09-13-2009, 12:24 PM
Dont forget a noise in the head will be twice as fast then a noise in the bottom end cause the cams spin faster then the crank.

Pacman
09-13-2009, 02:31 PM
Uhhh.... what engine is in the car? SR or KA? :mepoke:

Sileighty_85
09-13-2009, 06:13 PM
Uhhh.... what engine is in the car? SR or KA? :mepoke:

Its SR cuz he said hes gonna go PFC (which they dont make for KA)

MrFairlady
09-13-2009, 07:06 PM
I'm gonna get a video tomorrow and let you guys hear it.
It is Def a Phantom noise.When your Listening on 1 side of the Engine (exhaust side) it sounds like its on the other side and Vise Versa.CRAZY.started as a very lite tick like exhaust leak or something.After a 2 1/2 gear Full Throttle Stomp it showed up AFter.
Car Drives & idles perfectly Fine.

It will Not make the noise untill a few mins after the Vehicle as Idle'd for a bit and somewhat warm.Then you rev it and tick,tick,tick right about 3000-3500 and then stops.You have to hold the RPM's at 1 rev to hear it or you will miss it.It is somewhat loud also.
Anyone ever Cracked a Flywheel?? It is a Gay "F1" Chromoly F/W and thats what a Lexus tech buddy of mine Thinks its could be.




Background:
Sr20 blktop,GT2860,93 oct,1 step colder plugs (that were actually pretty White)Greddy Oil pan,Greddy filter Relocate,Enth Tune ECU for Z32,550cc d/w,50psi bas fuel press per Scott @ Enth,FMIC & just got it running 15psi which is what the tune was for.I have no oil press gauge nor does the stock light one work.A/fs at full boost are in the 11's.

69datsun510
09-15-2009, 03:45 PM
An easy check to locate which cylinder the problem is coming from do the following:

start the engine, warm up, pull No. 1 spark plug wire and rev engine, listen for knock, replace spark plug wire.

Repeat procedure for each cylinder.

Which ever cylinder that the wire was removed and the knock was not heard upon revving the motor, would be the bad cylinder. This test indicates problems with the piston or piston pin, bottom end knocks would knock no matter what.

MrFairlady
09-20-2009, 10:27 PM
Welp.After Trying Pulling Injec Plugs while Revving..turns out #2 Cyl may have been the Culpret.

Pulled engine today and Drained oil...Milky metal.Damnit.

So Picked up my new bare but Loaded Block today as well.
Should I replace OEM Oil Pump??Or Trust whats on it?It is Buddy's old,old block back when he was into Nissans.So there is some History @least.Block's Been sitting for prob 2-3years wrapped (no rust,etc).

Plan:
Apexi' or Power Enterprises Thicker head gasket (or opnions)
ARP headstuds
Oil Pump?>>
Competing my Oil Cooler Setup (greddy oil Housing w/ built Thermo,etc)

What Else Should I go ahead and Replace??

Not You
09-21-2009, 11:19 AM
Pull a spark plug to isolate the noise. If it goes away when one of the plugs is pulled, you found the cylinder it is located in. If you do this and it doesn't go away, it's in the head.

If it truely is a rod knock, it'll get louder and harder the higher you rev it.
This is what I do, hold it @ the rpm it makes the noise though

MrFairlady
09-21-2009, 03:02 PM
This is what I do, hold it @ the rpm it makes the noise though

Thanks But,Please Re-read the post above yours.I did.That part has been completed.

Motor Out now and Head off.So far everything looks good.. minus the oil that was drained.
Taking oil Pans off tonight.

Thanks but I'm on to another question:
"what should I replace while its out and this Block that I have,has been sitting for 3years"

OEM Oil PUMP??
Valve Springs & Retainers?? B/C package is nice and Affordable..Any good?