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Engine ticking still, After lifter replacement.

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02grandprix

New member
Hey whats up guys. I having trouble here .The noise is coming from the rear of the motor. Ticking taping sound. Not rod knock. Heard more at idle and when throttle is applied the noise gets faster and quieter. And then when released the tapping comes back. So my friend and I Checked all rockers and push rods. Valve springs were not broken.Checked all old lifters that were removed none of them looked to be collapsed or damaged. We Installed new LS7 lifters, primed them all the night before in oil. Started the motor today and frigging noise is still there. Im at a loss. Do you guys have any ideas? TIA.
 


its prolly a injector

take a screw driver to your ear and put the other end on the FUEL rail, if you hear that sound, then its a injector, then to figure out which injector it is, just start unpluggin each of them one at a time

the car will miss fire of course, but if the noise stops then you know which one it is.

try that out and see if its an injector
 
I listened to the injectors and all sounded normal. I dont have a any miss fires at idle. On Monday ill have my friend give it a listen with the scope again. And start pulling the plug on each injector. To see if it quiets down. Before we replaced the lifters, thought we pinpointed it below the fuel rails on the rear of the block with stethoscope and figured it was a failed lifter. Thanks for the input man. Any other ideas I can try.
 


Yes I live in Methuen, MA and my car is in NH at a shop just over the state line. My friend checked and pulled each injector cable off of the injector and there was no change in noise from the injectors, and he also checked all spark plugs and found no damage. If it was a chipped piston would a leak down or pressure test show up low?

Before this started, I changed the oil and held a flashlight to the pan of oil, and saw what looked like a glittery oil I ran a magnet through the oil and nothing clung to the magnet. Would the glitter look indicate a worn down CAM shaft or would this be caused from regular wear and tear? Thank you in advance for any help or suggestions.
 
"glitter" in the pan you see is most likely copper, from a bearing. It wont be magnetic of course, but if you SEE it in the pan, then that's not good. You have bearing wear, or damage.

This can be some of your problem...low oil pressure or contaminates in the oil can cause bearing damage. You might have toasted a rod bearing, and what you hear is rod knock, meaning the rod has excessive play on the crank, and as you rev. the engine the oil pressure goes up, and the tolerances decreased making the sound quiet down, or go away. When the RPM's go down, the oil pressure does too, and the tolerances increased and the knock comes back.

I think your probably due for either a rebuild if you stop driving it now, or a replacement if you keep on driving it. (replacement meaning engine failure)

~F~
 
the up and down in oil pressure can quiet down rod knock if its not too bad of bearing damage, but low oil pressure can also make lifters chatter like this too, because they dont have enough pressure to pump them up with oil, so you hear them "screaming" because they are thirsty for oil.

The increased gap somewhere, where the bearing is damaged or trashed can cause low oil pressure because its just gushing out a BIGGER opening that hat it should be, and the rest of the engine is starved for the oil it needs.

I would suggest getting a oil pressure tester on the engine, and seeing what you have.

Most everyone with a aftermarket gauge set sees 60PSI almost all the time, others see 60 at a cold start, and as the engine warms up, the pressure drops. So on a cold start it can be 60 at idle, and once warmed up, it can be as low as 22 or 25 PSI. Sometimes its not REALLY that low, as the senders are not that great to go by. Just telling you what the gauge may read, and how it can very from car to car/gauge set to gauge set.

~F~
 


ya, as long as the pressure increases with RPM your good.

Our oil pumps are pretty fail safe, but cant say the same for the cheap pop-tin aluminum front engine cover that houses it. Seen some front covers pretty screwed up.

~F~
 
Man I hope not. I have an autometer oil pressure gauge. At cold start up its 75 psi. When reached opperating temp at Idle its about 40psi. As soon as I hit the gas the pressure jumps to 65. My friend checked the header to block bolts and wrapped the flex pipe no change in noise. No exhaust leaks. Tomorrow he is doing a compression test and Ill have him check the oil again. Is it a common failure to have the bearings wear out if thats my problem. Ill have him read these replys and see if he can check the rod bearings. Can you access it threw the oil pan? Is there a way to check before tearing into the motot? Thanks for your help.
 
you can access the main bearings via oil pan but the oil pan is a PITA to get off while the engine is in the car.

For some reason these engines can run fine or will all of a sudden chuck a rod bearing just cause...

Note: I am jealous of your transmission.... :D
 
I might have an update tomorrow. Oh by the way thanks man for the compliment on the trans. Its got 28k on it. Its been pretty good. Just was a long process with shipment and building it.
 


Well I picked the car up today. I need to save for a motor. which sucks. I going to drive it till it breaks, I need it for work. Hopefully Ill have the money soon to get the ball rolling. I getting a L32 motor. Am I able to use the same injectors and rockers I have in the L67 to swap to the L32. And will the headers I have fit up to the new motor.
 
My friend checked all compression came back normal, had to race car engine builders look at my car, both seem to think or know its not engine failure and sounds more a rocker or push rod issue. I have been still driving it, may hold off on a engine till i dig a little deeper. Its just sucks.
 
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