LT1FirebirdSLP

iTrader: (2)

The sound in question is a sound that would be made if you tapped two glass bottles or metal rods together.

Motor is brandy new. 355, all forged lower internals, cc306 cam, new lifters and valvetrain components, all new, high volume oil pump.

Just noticed today it started making this sound today.

A few points, normally since the new motor, idle is around 60 psi oil pressure, but now since the sound developed, its around 40 psi.

It seems to only do it hot. No noticeable lack of power in any range. Can hear the noise most when decelerating or accelerating.

Oil on the dipstick is still clear, no metal flecks.

With the hood open, the sound seems to come from the top of the motor.

The noise increases in frequency with the revs of the motor.

Thats about all the information I have. The highest revs the motor has seen is about 6400 but that was a good while before this noise developed.

Any pointers or thoughts would be greatly appreciated.

BALLSS

use a stethoscope or piece of vacuum hose to your ear and proble each cyl on valve cover and exhaust header to see if you can pin point any one over the others. May just be a lose rocker

the oil pressure drop is concerning though....that points to bearing wear...and noise is not good. you don't see metal flakes in oil, good...cut open oil filter to see better wtf may be in there...if metal flakes..you need to pull motor and address bearings before severe damage

shbox

Post something we can hear. Why the HV oil pump?

GIZMO

iTrader: (8)

I wouldn't run it. As you have lost so much oil pressure along with your knock, you probably have a failed bearing. I would drop the oil pan and pull the valve covers.

LT1FirebirdSLP

iTrader: (2)

Bringing it to my builder tuesday morning. It just has to survive an hour ride home from where i am now.

LT1FirebirdSLP

iTrader: (2)

HV oil pump to support the extra horsepower and also improve oil delivery under cornering.

hrcslam

HV pump does not help under cornering and high revs, it hurts unless you have a much larger oil pan and baffles or dry sump.

Does the oil pressure drop when you rev it? Try this, put it in 3rd at like 40mph and give it the go go pedal. But stay in third, what happens to the oil pressure?

LandcruiserNZ

if its a bearing problem that'll probably be the trip that'll write off the bottom end of your engine, can you get it towed or put it on a transporter?

LT1FirebirdSLP

iTrader: (2)

Thanks for the advice and support all.

Seems to be more of a chirp, and less of a ting ting ting. Its rather humid and wet in the Northeast today so all signs are pointing at something in the accesory drive. I let it cool and started it up and didnt make a peep til it got warm. It just sounded so high pitched and was so short in duration. I'm gunna analyze further and report back.

HV oil pump is paired with a Canton 6 quart (almost 7 in actuality) pan with baffles. Not running a stock pan. Car at idle runs about 60-70 psi cold and apparently around 40 warm, which is mildly suspicious since i never noticed it before. When warm, any gas instantly brings oil up to around 60 psi and increases to around 80 at near redline.

Should also mention I was able to drive the car home nary a problem. The noise seemed to come and go as best I could hear considering its LTs through straight pipe and out a GMMG catback.

cardo0

We need a sticky just for engine noise. Every time some one has an engine noise they just post the question and dont bother to make any effort themselves and expect a good answer from someone across the internet that cant even hear the noise. Why dont u just get off your butt and search for a diagnose and try and do something first. Theres only like 4 diagnose for any engine noise.
1- locate with stethoscope
2- pull plug wires one at a time
3- open oil filter for metal
4- disassemble engine

A stupid hobo fake stethoscope is <$10
Pull the plug wire cost nothing
cut open oil filter = cost of oil change
dissemble engine - better now than let the engine eat itself

This guess what my noise is has become more than a stupid exercise here. If your too lazy to get off your keyboard and look u dont deserve an answer.


The oil pump is a positive displacement pump and output is linear with rpm until it reaches the bypass limit and stays at that max press setting. So u at least have a bad oil pump and the oil pan needs to come off anyways.

SS RRR

iTrader: (2)

Like this?


Or like this?

96capricemgr

iTrader: (1)

If you suspect accessory just pull the belt, the LT1 can run a long time(till battery dies) without a belt on, it isn't like other engines that could overheats somewhat quickly.

The HV oilpump was a bad choice, if you are fortunate enough to find an external cause for this problem GREAT but always keep an eye on the oil pressure because you are likely to wipe out the drive gear. If the engine comes out put a standard volume pump in it.

Anyone who told you it needed a HV to support the extra HP is an idiot, that pump is more likely to cause damage than fend off any. Pan capacity helps avoid sucking the pan dry but does not address cavitation, filling the valvecovers, wearing out the drive gear.

A few really high HP builds might make use of one with really loose bearing clearances but on a normal modest street build it ONLY offers problems.

LT1FirebirdSLP

iTrader: (2)

Good points made by all. Normally, I would dive into investigating the noise through the methods offered but I was over an hour away with not tools, no shop, no nothing. So I had to make my best decision based off of what I knew and what I could see.

FWIW I did a good bit of googling and you tubing before posting to see if I could find a similar sound but, there really isn't anything like it. That is why I presented as many facts that I knew to get the best guess from others.

It's still getting put up on a lift, examination of the oil filter yada yada, just as a cursory inspection.

Keyboard was my only option given my location and assets. So I got off my butt, and popped the hood, and looked and listened with what I had. I think it's hilarious that when someone asks a question around here, the assumption is made that OP has made absolutely zero effort to self diagnose his/her problem.

TBD on the "bad" pump. But as a note, through the power band, psi is linear up tip about 80-90.

cardo0

Heck u didnt get your hands dirty. I thought u were a lazy azz. With that lame excuse it proves it.

Goodby.

96capricemgr

iTrader: (1)

All you need to pull the belt is a 13mm ratchet or wrench to relieve the tensioner. If you want to drive a modded car a simple tool kit should be in the car at all times, even a $20 blowmolded kit something.

hrcslam

I had one of those kits for about 20 minutes once. Ratchet broke, I returned it. But agreed a small tool kit should be in the trunk of every car, even bone stock, even if you are not a mechanic. Along with a road side emergency kit.

LT1FirebirdSLP

iTrader: (2)

Pulled off the accesory belt today and the noise seemed to disappear. Poked around with a piece of hose for awhile too with nothing noticeable while the belt was off. Once the belt went back on the noise didn't seem to come back. It's so high pitched its hard to tell it between a chirp and a clink and it never stays consistent.

Thanks for those videos. The sound isnt similar to either, and it doesn't sound anything like rod knock.

Jr.Samples

Didn't sound internal from you vids. Auto car? Crazy but check your flywheel/torque converter bolts. This sounded like an issue I had on a 5.3 truck with a bolt head intermittently hitting.


On another note I have read quite a few post on here where guys get a little upset because they do not like or feel the OPs know what they are doing or ask the right questions. Guess what guys? That is why they are here.

If you don't like someone's question simple don't answer. It belittles everyone hearing you **** and moan because you are so superior. There should be no dumb questions here. Sometimes posters are ignorant to facts and over their heads but to demean doesn't help.

LT1FirebirdSLP

iTrader: (2)

The noise has yet to come back. Been driving it everyday with nothing notable in terms of oil pressure or valve train noise.

@Jr. Samples. I agree. Sure, I should of had a toolset with me and all but I honestly felt the best way to get some ideas the quickest was to just ask. I apologize for being less versed on these cars than others. But I learn more every day. I could see though, where the reaction I got from asking such a question would have turned other possible OP's away from even asking a question in the first place. A forum is a place to discuss something. If everyone knew everything and was mechanically and technically superior in all respects, then there would be no point in even having a forum.

3 pedal SS

iTrader: (1)

The last two posts are right on. Noises can be difficult at best....Good luck..