Uh, Oh...Something's Knocking Internally! HELP!
Uh, Oh...Something's Knocking Internally! HELP! Today, while getting on the interstate, I nailed it and took it to redline, but I didn't even hit the rev limiter. As I got off at the next exit, I had the windows down and I started hearing a knocking sound coming from the engine, and it is a LOUD knocking sound. I checked it with ATap, and I don't seem to be missing, but it sounds like something's knocking under the intake.
I've got a set of spare pushrods laying around, so I'll check those 1st, but this is NOT a slight ticking that pushrod problems normally cause, this is a knock. Could a broken pushrod cause a loud knock? It almost sounds as if I've thrown a rod or spun a bearing.
If it's anything more serious than a broken pushrod, then it's going to be quite a while before I can get this fixed.
Are there ANY LS1 shops in GA that could do a rebuild? How much are we talking for a rebuild?
I'm hoping someone here will tell me that that's exactly what a broken pushrod sounds like, since I can fix that myself, but I think it sounds more serious...HELP!
I've got a set of spare pushrods laying around, so I'll check those 1st, but this is NOT a slight ticking that pushrod problems normally cause, this is a knock. Could a broken pushrod cause a loud knock? It almost sounds as if I've thrown a rod or spun a bearing.
If it's anything more serious than a broken pushrod, then it's going to be quite a while before I can get this fixed.
Are there ANY LS1 shops in GA that could do a rebuild? How much are we talking for a rebuild?
I'm hoping someone here will tell me that that's exactly what a broken pushrod sounds like, since I can fix that myself, but I think it sounds more serious...HELP!
Re: Uh, Oh...Something's Knocking Internally! HELP! Damn dude.....sounds like the bad luck fairy was all over Middle Georgia today.....first Lisa's dad, now your car.....what's next?
Re: Uh, Oh...Something's Knocking Internally! HELP! How's the oil pressure ?
If the oil pressure is low...
If not, check the pushrods first and see what you find...
Good luck !
Bad30th
If the oil pressure is low...
If not, check the pushrods first and see what you find...
Good luck !
Bad30th
Re: Uh, Oh...Something's Knocking Internally! HELP!
How's the oil pressure ?
If the oil pressure is low...
If not, check the pushrods first and see what you find...
Good luck !
Bad30th
If the oil pressure is low...
If not, check the pushrods first and see what you find...
Good luck !
Bad30th
I won't have time to tear into it until this weekend, but I'm hoping it's just a pushrod. The tach read 6100 when I looked down at it yesterday. Could my headers have allowed the engine to rev quick enough that the rev limited didn't catch it and cause me to bend/break a pushrod? I do have an M6 and I'm sure I didn't miss a shift.
Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
Re: Uh, Oh...Something's Knocking Internally! HELP! really sounds like a bearing problem to me. When you restart it when its cold, the oil is thicker and can mask it somewhat.
Drain the oil and look for anything metallic looking in it. I wouldn't drive it anymore because if it is a bearing...the more you drive the worse you are tearing up the inside of the motor
Drain the oil and look for anything metallic looking in it. I wouldn't drive it anymore because if it is a bearing...the more you drive the worse you are tearing up the inside of the motor
Trending Topics
Re: Uh, Oh...Something's Knocking Internally! HELP! It's had nothing but Mobil 1 5W-30 since 2500 miles and it's got 74K miles on it now.
I'll check the pushrods and then check the oil after I do that...if it is a pushrod, then I was going to have to change the oil anyway after I change pushrods, and if it isn't a pushrod, then I'll check it to see what I've got.
I had new lifters installed last summer and I've been getting a little metal dust on my oil drain tip ever since, but it wasn't copper colored like a bearing...
The noise really sounds like it's coming from the top of the motor...specifically on the driver's side.
What makes you think this is most likely a bearing problem?
I'll check the pushrods and then check the oil after I do that...if it is a pushrod, then I was going to have to change the oil anyway after I change pushrods, and if it isn't a pushrod, then I'll check it to see what I've got.
I had new lifters installed last summer and I've been getting a little metal dust on my oil drain tip ever since, but it wasn't copper colored like a bearing...
The noise really sounds like it's coming from the top of the motor...specifically on the driver's side.
What makes you think this is most likely a bearing problem?
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Joined: Nov 2001
Posts: 8,484
Likes: 0
From: Cecil County Raceway!!!
Re: Uh, Oh...Something's Knocking Internally! HELP! well the fact it was probably hot out (GA), you run thin (5W30) oil and you were near redline...
that is not a good combo
then like I said above...the fact it was quieter when cold (thicker oil)
that is not a good combo
then like I said above...the fact it was quieter when cold (thicker oil)
Re: Uh, Oh...Something's Knocking Internally! HELP! I'm hoping you're both wrong...but my fear is you're both right...
The last time I had a car knock like my Z is now, I sold the car for a HUGE discount and moved on...I don't plan to do that with my Z. If it is a spun bearing, is the only way to correct that a complete rebuild? How much do LS1 rebuilds run?
It hadn't been knocking at all before and gradually gotten worse, this just happened after one trip to 6100 RPM. I don't understand why the rev-limited didn't catch it. It really does sound like the knock is in the top of the engine, specifically the driver's side. Does that help with the diagnosis?
I guess I'll find out for sure when I take a look at the pushrods...that's what I'm praying is the problem, but as I said earlier, it really does sound BAAAD!
The last time I had a car knock like my Z is now, I sold the car for a HUGE discount and moved on...I don't plan to do that with my Z. If it is a spun bearing, is the only way to correct that a complete rebuild? How much do LS1 rebuilds run?
It hadn't been knocking at all before and gradually gotten worse, this just happened after one trip to 6100 RPM. I don't understand why the rev-limited didn't catch it. It really does sound like the knock is in the top of the engine, specifically the driver's side. Does that help with the diagnosis?
I guess I'll find out for sure when I take a look at the pushrods...that's what I'm praying is the problem, but as I said earlier, it really does sound BAAAD!
TECH Enthusiast
Joined: Jan 2002
Posts: 531
Likes: 0
From: Helendale, Ca (SilverLakes)
Re: Uh, Oh...Something's Knocking Internally! HELP! Possible.......
Stretched a rod bolt which results in a hammering sound.
Cracked a piston around the pin area, also makes a knocking sound.
Broken valve spring, will make noise but not as loud as above.
These do not call for a rebuild. Just replace the bad parts.
Stretched a rod bolt which results in a hammering sound.
Cracked a piston around the pin area, also makes a knocking sound.
Broken valve spring, will make noise but not as loud as above.
These do not call for a rebuild. Just replace the bad parts.
TECH Enthusiast
Joined: Jan 2002
Posts: 597
Likes: 0
From: Orange Park, FL
Re: Uh, Oh...Something's Knocking Internally! HELP! Same noise has been happening to mine since I installed the Comp R lifters and new heads. It is intermittent though. Thought it was rockers, shimmed up YT's and thought we had it fixed, no joy. Started adding 2 qts of 15W-50 Mobil 1 to 4 qts 10W-30, no joy. Taking another oil sample in tomorrow to see if the metal content has increased. What gets me the most is how intermittent it is. Usually comes on after a WOT run followed by steady cruise. I wish the damn thing would just blow up so I could convince the wife that I REALLY need to re-build with forged internals!!
Good luck to you bro and I hope you find the problem.
Good luck to you bro and I hope you find the problem.
TECH Apprentice
Joined: Nov 2001
Posts: 336
Likes: 0
From: Aub, Fl
Re: Uh, Oh...Something's Knocking Internally! HELP! 6100 is not enough to bend the stock pushrods, aren't they good for up to like 6700? I know a guy who was shifting at 6700 with stock push rods in his bolt on 11.40 car! it had tuning but the pushrods were stock and he held out 3rd to 6700 to clear the traps, he never had any problems. My A4 has hit the rev a few times when it was spinning and I have it up to 6400.
Re: Uh, Oh...Something's Knocking Internally! HELP! Its not the high rpm that hurts the pushrods, its the valvefloat that in turn bends them. There is a distinct difference between what bent pushrods/valvetrain noise sounds like and a rod knocking.
Re: Uh, Oh...Something's Knocking Internally! HELP! ...I'm just baffled by why this happened at all...I did NOT miss a shift, and I didn't even hear it bouncing off the rev limiter. I've had nothing to indicate that my oil pump was having any problems and I don't burn any oil. This hasn't been a soft knock that's gradually gotten louder, this was a problem that developed immediately after a high rev. I too fear it might be a rod or bearing, but is it a least possible that if the pushrod is actually broken that that could cause the knock?
I'll tear into the heads on Sat., so I'll know more then, but I'm actually loosing sleep over this at the moment...
I'll tear into the heads on Sat., so I'll know more then, but I'm actually loosing sleep over this at the moment...
TECH Apprentice
Joined: Nov 2001
Posts: 336
Likes: 0
From: Aub, Fl
Re: Uh, Oh...Something's Knocking Internally! HELP! You'll get it figured out, don't worry about it. I just had to re-build mine because it was smoking like a frieght train @ WOT and burning a LOT of oil! happened right after headers a few months back, it really had me upset too, but I finally decided not to let it get to me, I bit the bullet and re-built it. Glad I did cause the rings were shot at under 60,000 miles! 
Look at it this way... What ever it is, it can be fixed! 
Look at it this way... What ever it is, it can be fixed! 
Re: Uh, Oh...Something's Knocking Internally! HELP! ya if you broke a rod, your whole car would shake. even if you stretched a rod bolt it would shake, since it knocks the balance off. if it isnt anything in the top end, then you could unbolt your motor mounts, and jack your motor up a little so you can take the oil pan off and do a visual check of everything
Re: Uh, Oh...Something's Knocking Internally! HELP! I just pulled all 16 pushrods and they were fine...I guess I have a more serious failure
My wife and I close on our new house in a week, so obviously, this didn't need to happen right now. My Z isn't my daily driver, but it'll most likely sit a long time before I recover from our 1st home purchase and have money to work on my Z
LS1Jay, It's been less than 1K miles since I did headers too...what is it about headers that could facilitate this kind of failure?
My wife and I close on our new house in a week, so obviously, this didn't need to happen right now. My Z isn't my daily driver, but it'll most likely sit a long time before I recover from our 1st home purchase and have money to work on my Z
LS1Jay, It's been less than 1K miles since I did headers too...what is it about headers that could facilitate this kind of failure?
