Can the opti be making this noise from the front of my motor?
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Joined: Nov 2000
Posts: 1,937
From: Ft. Worth, TX
Can the opti be making this noise from the front of my motor?
Sounds like loose bearings knocking from the very front of the motor.
I know the opti has a bearing in it, its the factory opti w/90k miles on it, but don't know if it could make this much noise.....maybe the water pump gear/bearing?
I have a stethoscope with a tube connected to it, the noise is definitely at the front and can be heard the loudest when the listening tube is on the waterpump and opti housing.
It seems to be loud enough to set off the knock sensor at a constant 3-5 degrees as well.
I know the opti has a bearing in it, its the factory opti w/90k miles on it, but don't know if it could make this much noise.....maybe the water pump gear/bearing?
I have a stethoscope with a tube connected to it, the noise is definitely at the front and can be heard the loudest when the listening tube is on the waterpump and opti housing.
It seems to be loud enough to set off the knock sensor at a constant 3-5 degrees as well.
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Joined: Oct 2006
Posts: 6
From: Mansfield, TX
I say waterpump, I have replace at least 100 and a lot of them have half the bearings missing. if its a rolling grinding noise replace the pump, at least check it when you get it off abd I bet the bearings are missing. Look at it like this, you have to pull it to get the opti out anyway.
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Joined: Nov 2000
Posts: 1,937
From: Ft. Worth, TX
I just bought an opti from Jason just in case, for $235 for a Delco, if it ain't it, I'll have a spare. Its coming apart this w/e and didn't want to be without parts...
If its the waterpump, I can get those from the local auto store.
I hope its not the timing chain, was just replaced with a GM Extreme LT4 HD set when the heads/cam swap was installed....does not seem to do it all of the time, sometimes its not near as loud...seems to get louder the hotter it gets or after its revved high....also, there's no evidence of metal in the oil....
It does sound like a rolling grinding noise...
If its the waterpump, I can get those from the local auto store.
I hope its not the timing chain, was just replaced with a GM Extreme LT4 HD set when the heads/cam swap was installed....does not seem to do it all of the time, sometimes its not near as loud...seems to get louder the hotter it gets or after its revved high....also, there's no evidence of metal in the oil....
It does sound like a rolling grinding noise...
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Joined: Feb 2004
Posts: 1,154
From: VA
Sounds like loose bearings knocking from the very front of the motor.
I know the opti has a bearing in it, its the factory opti w/90k miles on it, but don't know if it could make this much noise.....maybe the water pump gear/bearing?
I have a stethoscope with a tube connected to it, the noise is definitely at the front and can be heard the loudest when the listening tube is on the waterpump and opti housing.
I know the opti has a bearing in it, its the factory opti w/90k miles on it, but don't know if it could make this much noise.....maybe the water pump gear/bearing?
I have a stethoscope with a tube connected to it, the noise is definitely at the front and can be heard the loudest when the listening tube is on the waterpump and opti housing.
If you've got a fair amount of miles (60k) on the WP and opti just go ahead and replace both.
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Joined: Nov 2000
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From: Ft. Worth, TX
The wp has about 20k on it, the opti has 90k...and it didn't start making the noise till it was revved well up to 6k rpms maybe a bit more, a few times after the heads and cam install.
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Joined: Oct 2006
Posts: 477
From: Seattle area
Lemme guess. It's OK when the engine is cold, but gets worse as it warms up.
Mine started making this noise after I put the GMP LT4 Severe Duty timing set in it. I literally ripped all my hair out looking for the source of the noise until I finally gave up on it. Then, I was at Ellis Groo's place, heard the same noise on one of his cars, and he told me its the severe duty timing set. Makes sense to me, despite the noise, I've never had any problems with it.
Not saying you have the same noise, but it sounds similar.
Mine started making this noise after I put the GMP LT4 Severe Duty timing set in it. I literally ripped all my hair out looking for the source of the noise until I finally gave up on it. Then, I was at Ellis Groo's place, heard the same noise on one of his cars, and he told me its the severe duty timing set. Makes sense to me, despite the noise, I've never had any problems with it.
Not saying you have the same noise, but it sounds similar.
Thread Starter
Registered User
Joined: Nov 2000
Posts: 1,937
From: Ft. Worth, TX
Lemme guess. It's OK when the engine is cold, but gets worse as it warms up.
Mine started making this noise after I put the GMP LT4 Severe Duty timing set in it. I literally ripped all my hair out looking for the source of the noise until I finally gave up on it. Then, I was at Ellis Groo's place, heard the same noise on one of his cars, and he told me its the severe duty timing set. Makes sense to me, despite the noise, I've never had any problems with it.
Not saying you have the same noise, but it sounds similar.
Mine started making this noise after I put the GMP LT4 Severe Duty timing set in it. I literally ripped all my hair out looking for the source of the noise until I finally gave up on it. Then, I was at Ellis Groo's place, heard the same noise on one of his cars, and he told me its the severe duty timing set. Makes sense to me, despite the noise, I've never had any problems with it.
Not saying you have the same noise, but it sounds similar.
I'll let ya'll know if I find anything with the wp and opti this w/e...not messing with the timing set at this time...
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Joined: Nov 2000
Posts: 1,937
From: Ft. Worth, TX
Yep I have the LT4 KM, but as loud as this is, that would not matter. If you can hear knock, there's no way to keep it from removing timing besides zeroing out the tables in the PCM.
There would have to be an aweful lot of slop in that chain to make the noise its making unless its grinding into the front cover or something, but I'm not finding any evidence of metal/flakes in the oil. I did not install the timing gear so I can't say how tight the Severe Duty LT4 chain is when installed. The sound does sound like a bearing missing some of the *****..... Guess I'll figure out Saturday what it is...
There would have to be an aweful lot of slop in that chain to make the noise its making unless its grinding into the front cover or something, but I'm not finding any evidence of metal/flakes in the oil. I did not install the timing gear so I can't say how tight the Severe Duty LT4 chain is when installed. The sound does sound like a bearing missing some of the *****..... Guess I'll figure out Saturday what it is...
Thread Starter
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Joined: Nov 2000
Posts: 1,937
From: Ft. Worth, TX
well, I replaced the opti Saturday and the 90k mile opti did sound a little rough when you spin the bearing..but appearently I did not install the replacement opti correectly per my other "opti" post and it made the same, but not as loud noise.....so tonight I took it part again and replaced that new opti that I tightened down to the timing cover with another new one..this time making sure it was flush with the timing cover before installing the bolts....well it still makes the noise so I guess I have a spare opti now...
I'm assumming you are right vgeglia that its the HD LT4 timing chain so I'm not going to worry about it any more....my LT4 in the truck does not have it and it works flawless....wonder why its so noisy??
I'm assumming you are right vgeglia that its the HD LT4 timing chain so I'm not going to worry about it any more....my LT4 in the truck does not have it and it works flawless....wonder why its so noisy??
