knocking noise with video and data
10-04-2014, 01:16 PM
#1
knocking noise with video and data And here we go again....
So I'm either crazy, Worst weekend mechanic in history, or there is no one competent left in the world except some of the guys here at LS1tech.
A refresh
Engine is stock refreshed 97 350 2 bolt with stock pistons, rods, crank. replaced parts are rings, bearings, oil pump with white spring, GM HD timing set, Lloyd Elliot custom ground cam, LS7 lifters with Trick Flow push-rods, LE2 heads. ODD1 conversion with OBD1 knock sensor and PCM (done for ease of email tuning by mad tuner and I had all the parts)
Bottom end was assembled by engine shop. had him inspect the bottom end and refresh the short block. Also had him pressure check the heads and make sure they were ready to bolt on.
I installed the Cam, timing set, and top end parts.
Had a problem with fel-pro 1074 leaking coolant past compression ring on gasket into cylinder. put 35 miles on engine before i figured it out. took the head off and tried a new gasket and it leak worse.
I then took the engine out and used a different set of gaskets (fel-pro 9966PT). I then pressurized the cooling system to 18psi for 5 days and found a leak in one of the intake runners and no water in the cylinders.
I then preformed a leak down test which was good on all cylinders even though it was done cold. I talked to Lloyd and he told me a way to fix the leak.
I took the heads off and cleaned all head bolts and bolt holes. I installed another set of 9966PT gaskets and re preformed the coolant test and leak down test and all was good. No leaks.
I have now put the engine back in the car and started it. when cold it sounds great. no strange noises rattles or anything. as it pressurizes the cooling system and come up to full temp and the oil gets up to temp a noise shows up that I have tried to catch in a video. To me it sounds like a rod knock but I can not hear it as I rev the engine up slowly or at a slow constant pace.
As the noise does appear the knock count on data master starts to go through the roof and it starts to retard timing at idle. To give you an idea the count went from constant 3800 at idle to 8000 with just a few short revs. On a side note that is very odd to me if I leave the radiator cap off and let the car come up to temp the knocks do not show up on data master but you can still hear the thing knocking at idle.
I will post up link to several videos showing the warm up sounds and specs on DM to full temp with the knock. I have removed the Accessory belt to rule out belt driven components already so I know it not that. I have also gone through and readjusted the valves 4 times while not running and 4 times running to try and find noisy lifter or rocker. and there is no change. Let me know what you think it is I have a feeling this thing is coming out again.
Cold idle
https://www.youtube.com/watch?v=AE4C...ature=youtu.be
Half way warm
https://www.youtube.com/watch?v=gpeG...ature=youtu.be
Full Temp
https://www.youtube.com/watch?v=9ZWj...ature=youtu.be
So I'm either crazy, Worst weekend mechanic in history, or there is no one competent left in the world except some of the guys here at LS1tech.
A refresh
Engine is stock refreshed 97 350 2 bolt with stock pistons, rods, crank. replaced parts are rings, bearings, oil pump with white spring, GM HD timing set, Lloyd Elliot custom ground cam, LS7 lifters with Trick Flow push-rods, LE2 heads. ODD1 conversion with OBD1 knock sensor and PCM (done for ease of email tuning by mad tuner and I had all the parts)
Bottom end was assembled by engine shop. had him inspect the bottom end and refresh the short block. Also had him pressure check the heads and make sure they were ready to bolt on.
I installed the Cam, timing set, and top end parts.
Had a problem with fel-pro 1074 leaking coolant past compression ring on gasket into cylinder. put 35 miles on engine before i figured it out. took the head off and tried a new gasket and it leak worse.
I then took the engine out and used a different set of gaskets (fel-pro 9966PT). I then pressurized the cooling system to 18psi for 5 days and found a leak in one of the intake runners and no water in the cylinders.
I then preformed a leak down test which was good on all cylinders even though it was done cold. I talked to Lloyd and he told me a way to fix the leak.
I took the heads off and cleaned all head bolts and bolt holes. I installed another set of 9966PT gaskets and re preformed the coolant test and leak down test and all was good. No leaks.
I have now put the engine back in the car and started it. when cold it sounds great. no strange noises rattles or anything. as it pressurizes the cooling system and come up to full temp and the oil gets up to temp a noise shows up that I have tried to catch in a video. To me it sounds like a rod knock but I can not hear it as I rev the engine up slowly or at a slow constant pace.
As the noise does appear the knock count on data master starts to go through the roof and it starts to retard timing at idle. To give you an idea the count went from constant 3800 at idle to 8000 with just a few short revs. On a side note that is very odd to me if I leave the radiator cap off and let the car come up to temp the knocks do not show up on data master but you can still hear the thing knocking at idle.
I will post up link to several videos showing the warm up sounds and specs on DM to full temp with the knock. I have removed the Accessory belt to rule out belt driven components already so I know it not that. I have also gone through and readjusted the valves 4 times while not running and 4 times running to try and find noisy lifter or rocker. and there is no change. Let me know what you think it is I have a feeling this thing is coming out again.
Cold idle
https://www.youtube.com/watch?v=AE4C...ature=youtu.be
Half way warm
https://www.youtube.com/watch?v=gpeG...ature=youtu.be
Full Temp
https://www.youtube.com/watch?v=9ZWj...ature=youtu.be
10-05-2014, 10:36 AM
#4
No leaks in the exhaust. Checked it cold and hot and have a few burns now lol. I even let it cool and readjusted the slip fits to make sure. all is tight, no leaks and the noise came back at idle only. It sounds like its coming from the front of the engine. I'm gonna get the front end higher and use a screw driver to listen to the oil pan while it's making the noise.
10-05-2014, 09:06 PM
#6
Village Troll 
iTrader: (2)
I don't think it is. It was just something else I heard. If the knock disappears when the engine is revved it usually is not top end related. Also, when you have exhaust leaks they get louder when the engine is under load.
10-07-2014, 11:37 AM
#7
It's coming from the front of the engine. I took a screw driver under the car while it was running and listened to everything. timing cover, oil pan, water pump and the opti has a noise that matches up to the timing and sound of the noise I here. It gets quieter with engine speed when just listening with out screw driver and if i listen to it at the opti I can here it with a screw driver even when the engine speed goes up. Dont know if it is a bearing or what. Took the car out and drove it and the noise has picked up a slight swooshing sound to it like something is rubbing inside the opti, or a bad bearing. Guess I get to pull it. It runs so I'm tempted to just drive it till something breaks at this point.