Bent Rod Ls-1
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From: Miami Fl
Bent Rod Ls-1
So the other night my engine starting ticking real bad with a slight misfire after a couple 1/8th mile runs. Long story short I bent one of the rods on the passenger side. I simply pulled the valve cover off and the rocker arm and yanked the bent rod out and replaced it. Now several days later there is and interminent high pitch sound from that area that sounds like a bearing when it locking up. I stopped using the car and i wonder if anyone knows what this noise could be. i also removed the belt to make sure its not a accessory bearing problem.
its a 98 ls-1 A4
its a 98 ls-1 A4
Last edited by Rconce01; Jan 22, 2010 at 10:54 AM.
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From: Miami Fl
Springs are fine and the car runs great, the squeak is scary though. I think the new rev limiter setting might have caused it. Maybe i'm wrong but this was the only recent change i made. In 5 yrs the car has never done this.
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From: Dyer, IN
I don't see an head upgrades in your sig, so if you are going to be exploring higher RPMs, you need to keep the valves from floating.
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From: Miami Fl
The tune set the shifts @ 6300 rpms with a 6500 rev limiter. Its an auto so the shirts were consistently done @ 6300 rpms. Might have been that valve float mentioned by Lucky.
by the way the bent part was inside the engine, can someone explain the difference between a compression test and a leak down test. I've only done compression tests.
Last edited by Rconce01; Jan 22, 2010 at 01:05 PM.
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I bet you have a bad rocker. The 97-2001 LS engines had a tendancy for the rocker trunion bearings to puke out of the side of the rocker. If all your bearings are gone, it can and will lock up. Pull the rocker off and make sure its in good condition and free to rotate.
I would check ALL of them. Look for needle bearing in the oil drain back areas in the head and see if there are any in there. They will find their way in to the oil pan. Just fish them out with a magnet and or install a magnetic drain plug if there are any in there.
BC
I would check ALL of them. Look for needle bearing in the oil drain back areas in the head and see if there are any in there. They will find their way in to the oil pan. Just fish them out with a magnet and or install a magnetic drain plug if there are any in there.
BC
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Tech Contributor
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From: Dyer, IN
The tune set the shifts @ 6300 rpms with a 6500 rev limiter. Its an auto so the shirts were consistently done @ 6300 rpms. Might have been that valve float mentioned by Lucky.
by the way the bent part was inside the engine, can someone explain the difference between a compression test and a leak down test. I've only done compression tests.
by the way the bent part was inside the engine, can someone explain the difference between a compression test and a leak down test. I've only done compression tests.
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Pro
Joined: Apr 2004
Posts: 719
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From: Miami Fl
I bet you have a bad rocker. The 97-2001 LS engines had a tendancy for the rocker trunion bearings to puke out of the side of the rocker. If all your bearings are gone, it can and will lock up. Pull the rocker off and make sure its in good condition and free to rotate.
I would check ALL of them. Look for needle bearing in the oil drain back areas in the head and see if there are any in there. They will find their way in to the oil pan. Just fish them out with a magnet and or install a magnetic drain plug if there are any in there.
BC
I would check ALL of them. Look for needle bearing in the oil drain back areas in the head and see if there are any in there. They will find their way in to the oil pan. Just fish them out with a magnet and or install a magnetic drain plug if there are any in there.
BC
When i replaced that rod the rocker was good i could see it was rotating freely and with not much play. Could it be that the plastic little trays that guide the rod in and hold the roller lifter broke and the roller lifter is not working in the proper direction?
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From: Miami Fl
Wow ok thanks this is very technical
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Melting Slicks
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From: Rockford Illinois
My buddy did the same thing. I would remove all the pushrods on that side and roll them on glass. Just because they dont look bent doesnt mean they arent. Glass will tell you. I would get some chromoly pushrods. Check your lifters, at any rpm with a busted pushrod like that, you can damage the lifter.
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From: Miami Fl
My buddy did the same thing. I would remove all the pushrods on that side and roll them on glass. Just because they dont look bent doesnt mean they arent. Glass will tell you. I would get some chromoly pushrods. Check your lifters, at any rpm with a busted pushrod like that, you can damage the lifter.
The car was running fine after the initial push rod replacement (the one in the pic), since the other one i just found was not as bent apparently it did not affect the performance of the engine or the idle. I really don't want to remove my long tube headers and that head. Should i double check the rockers and all the push rods and reassemble and see if the squeak went away?
By the way is my stock valve train going to fall apart due to this 6300 rpms? because this is really starting to suck and its only been several weeks of abuse and i've had to wrench a bit, so sticking a stock tune is making more sense for me.
Last edited by Rconce01; Jan 22, 2010 at 08:00 PM.
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From: Dyer, IN
So far i removed the whole intake and the plate beneath it to take a small peak at the cam. I removed all the rods and rockers on the passenger side and found that the intake push rod on the last cylinder was also bent and rubbing against the aluminum hole in which it operates. Perhaps that was the squeaking sound. All the springs are fine and the valves are not stuck open or closed they are operating as intended. I have not accounted for all the needles in all the rockers since they cannot be seen. Are you supposed to pull the rocker apart somehow and count the needles.
The car was running fine after the initial push rod replacement (the one in the pic), since the other one i just found was not as bent apparently it did not affect the performance of the engine or the idle. I really don't want to remove my long tube headers and that head. Should i double check the rockers and all the push rods and reassemble and see if the squeak went away?
The car was running fine after the initial push rod replacement (the one in the pic), since the other one i just found was not as bent apparently it did not affect the performance of the engine or the idle. I really don't want to remove my long tube headers and that head. Should i double check the rockers and all the push rods and reassemble and see if the squeak went away?
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Joined: Apr 2004
Posts: 719
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From: Miami Fl
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I viewed your post at work and was unable to see the pictures until now: 
Holy CRAP!
My honest opinion is,,,your valves kissed the pistons. There are too many sceneros to go thru to speculate why. I bet ya that you have smiles on more than one piston. If it were me,,,I would re-evaluate the last seconds prior to the engine miss and then figure out what happened.
You have a UGLY issue somewhere. If you cant rip out the smoking gun,,you need to dig a little DEEPER!
Heres where I think you should see very soon:
BC
Holy CRAP! My honest opinion is,,,your valves kissed the pistons. There are too many sceneros to go thru to speculate why. I bet ya that you have smiles on more than one piston. If it were me,,,I would re-evaluate the last seconds prior to the engine miss and then figure out what happened.
You have a UGLY issue somewhere. If you cant rip out the smoking gun,,you need to dig a little DEEPER!
Heres where I think you should see very soon:
BC
Thread Starter
Pro
Joined: Apr 2004
Posts: 719
Likes: 21
From: Miami Fl
I viewed your post at work and was unable to see the pictures until now: Holy CRAP!
My honest opinion is,,,your valves kissed the pistons. There are too many sceneros to go thru to speculate why. I bet ya that you have smiles on more than one piston. If it were me,,,I would re-evaluate the last seconds prior to the engine miss and then figure out what happened.
You have a UGLY issue somewhere. If you cant rip out the smoking gun,,you need to dig a little DEEPER!
Heres where I think you should see very soon:
BC
Holy CRAP! My honest opinion is,,,your valves kissed the pistons. There are too many sceneros to go thru to speculate why. I bet ya that you have smiles on more than one piston. If it were me,,,I would re-evaluate the last seconds prior to the engine miss and then figure out what happened.
You have a UGLY issue somewhere. If you cant rip out the smoking gun,,you need to dig a little DEEPER!
Heres where I think you should see very soon:
BC
