littleblazer
Member
- Jul 6, 2014
- 9,265
<FIXED> Lifter noise & dull knocking (bottom end?) troubleshooting
- Thread starter Capote
- Start date
- Status
therealsethallen
Member
@littleblazer that sounds to me like a bad belt tensioner. The one next to the power steering pump, not to be confused with the the idler pulley above the A/C Compressor. Maybe that's worth a shot. Less than $50 to see.
Also might help if you could read live misfire data.
It's a cheap part, either Dorman 419-125 or GM ACDelco 12573024
Also might help if you could read live misfire data.
It's a cheap part, either Dorman 419-125 or GM ACDelco 12573024
littleblazer
Member
- Jul 6, 2014
- 9,265
Woa. That's gotta be the worst slap I've ever heard. It sounds like the 3.0l 4 cylinder with a flat cam in my boat... but slap isn't deadly.
Thanks for the input but if I recall correctly, it did it without the belt too. It almost sounds like a wrist pin knock to me, which should spell the end or anything. Similar sound to slap you know?
Little Blazer, that sounds more along the lines of piston slap.
And to add, my 05 with the I6 has a pretty noisy engine when cold, once it warms up it still makes some noise, I just chalk it up to an old engine as it runs great, and mostly sounds like piston slap. Give it a good check but there is a good chance that your engine is just getting a bit noisy with age.
And to add, my 05 with the I6 has a pretty noisy engine when cold, once it warms up it still makes some noise, I just chalk it up to an old engine as it runs great, and mostly sounds like piston slap. Give it a good check but there is a good chance that your engine is just getting a bit noisy with age.
Sparky
Member
- Dec 4, 2011
- 12,927
littleblazer I can't hear anything remotely out of the ordinary on that video... sounds like a quieter version of what my 02 sounded like.
If @Capote's truck sounds like that I'd not worry at all. Mine was easily 2x as loud as that for the entire time I had it from 112k to 215k, particularly when cold. When my exhaust manifold started leaking a bit it was louder, I just called in a diesel wannabe because it kinda had that diesel growl to it
If @Capote's truck sounds like that I'd not worry at all. Mine was easily 2x as loud as that for the entire time I had it from 112k to 215k, particularly when cold. When my exhaust manifold started leaking a bit it was louder, I just called in a diesel wannabe because it kinda had that diesel growl to it
Nope, mine doesn't sound even close to that, way quieter and it doesn't sound like a diesel like that Voy did.
littleblazer
Member
- Jul 6, 2014
- 9,265
You can't really hear it as well with the fan tbh.littleblazer I can't hear anything remotely out of the ordinary on that video... sounds like a quieter version of what my 02 sounded like.
If @Capote's truck sounds like that I'd not worry at all. Mine was easily 2x as loud as that for the entire time I had it from 112k to 215k, particularly when cold. When my exhaust manifold started leaking a bit it was louder, I just called in a diesel wannabe because it kinda had that diesel growl to it
07TrailyLS
Member
Ever think that it could be your timing chain tensioner clicking from being loose like mooses and MRRSM's? I've had a solid clicking in my valve train since I got the truck. Too scared to pull the valve cover off and see what's wrong
Mooseman
Moderator
When the chain was flopping around because of the bad tensioner, the noise was very irregular and only at idle and could hear and feel it was right at the top front of the valve cover with the chain hitting the guide.
Only way to know is to pull the valve cover, but I heard no noise near the timing chain with a stethoscope.
I haven't even bothered to diagnose this further, my work schedule doesn't permit such.
I haven't even bothered to diagnose this further, my work schedule doesn't permit such.
Here is a direct look at what is actually happening that causes ROD KNOCK...inside an engine looking at the problem face to face from the bottom up. The visual and audio value of this multi-media gem will be self-evident:
And another with equal instructional value using an external way to test for the problem:
And another with equal instructional value using an external way to test for the problem:
Last edited:
Update: Knock has become very loud, double checked torque converter bolts because it sounded underneath and in that area. Everything checks out with that. I'm very lost and bummed at this point.... It could very well be the timing chain because I can feel and hear the knock through the stethoscope on top of coil pack. Today I got a lean fuel code and afterwards it idled at 900 until I cleared the code. Did it again tonight with no code. Cleared codes through dash command to fix "hidden codes" and that fixed the idle to normal again.
I still need to get to doing that compression test. That'll give me more to go off of. I may have to hold onto my Cutlass now until this issue is diagnosed.
This blows...
I still need to get to doing that compression test. That'll give me more to go off of. I may have to hold onto my Cutlass now until this issue is diagnosed.
This blows...
This Guy's Engine sounds like his Timing Chain Tensioner has failed...and judging from the piled up snow on the ground nearby and observing from how readily he races the engine to high RPM... I suspect that if the Engine was literally Ice Cold when he first starts it up...racing the RPM so soon like that in Frigid Climates before the Engine Oil can get warm enough to make its way around inside the Stone Cold Engine Block may have precipitated this problem. Does your motor sound close to this?
Nah sounds different than that buddy. I'll get a video tomorrow of the sound. I just hope my phone picks up the sound accurately as it actually sounds in person.
Mooseman
Moderator
That video sounds more like a spun bearing (I have heard it on this engine, very similar but if you read the commentaries, turned out to be the alternator). I know exactly how a failed chain tensioner sounds like. It's a very irregular knocking and you will feel it right at the oil fill cap area. It also stops above idle.
Sorry for not being very active on my own thread here. I haven't done much else to further delve into this problem gents. Yesterday I took the belt off to confirm that it's more than likely not a belt connected issue. I was correct in that assumption, noise was still there. Only thing left now is to actually remove the valve cover and see what has broken or come loose under there. So i'm gonna order rocker arms, at least half of the lifters (since I doubt all of them, if not any are messed up, replaced them last year), and I already have valve springs that are unopened.
Should I even bother getting new valve cover gasket kit, since the gaskets on there aren't even 2yrs old?
Truck is still running great by the way
Should I even bother getting new valve cover gasket kit, since the gaskets on there aren't even 2yrs old?
Truck is still running great by the way
Okay, so I am getting ready to order new lifters and rocker arms for the rig. I have no idea what issue i'll find under the valve cover, hopefully not something far worse and end up having to take it apart again. I don't want to spend $200 ordering a whole new set of the lifters and rocker arms, so should I just get 12 of each? I gotta find the unused valve springs I still have, can't remember where they are at.
I wish I knew for sure what was broken, I know I won't end up using everything I order, but I figure if I order half of the components it's wiser than lets say 6 pairs or so of everything.
And after this i'm changing my oil, i'm not using Lucas additives anymore with my oil changes. I've heard and read up on how it causes air bubbles in the oil and can cause engine component failure. I've used it my last 2 oil changes, didn't have any issues my first time using it. This second time though, the loud tapping noise I've been going on about occurred shortly afterwards. I'm tempted to use Diesel Oil next time. Brandon used it on his rig and his engine became extremely quite.
And after this i'm changing my oil, i'm not using Lucas additives anymore with my oil changes. I've heard and read up on how it causes air bubbles in the oil and can cause engine component failure. I've used it my last 2 oil changes, didn't have any issues my first time using it. This second time though, the loud tapping noise I've been going on about occurred shortly afterwards. I'm tempted to use Diesel Oil next time. Brandon used it on his rig and his engine became extremely quite.
Mooseman
Moderator
I am always leery of additives, considering them to be nothing more than snake oil. Good oil, oil filters and proper intervals are all you need.
Diesel oil or fuel? I've used Shell Rotella 5W40 T6 oil in the past. Expensive stuff (here anyway) and from what I read, not better than Mobil 1.
Diesel oil or fuel? I've used Shell Rotella 5W40 T6 oil in the past. Expensive stuff (here anyway) and from what I read, not better than Mobil 1.
Mooseman
Moderator
It's a good oil. I've used it in the past in my 4.2. Found that it needed more top ups though. It probably has a different additives package for diesel engines, maybe to keep them cleaner, I don't know. I tried the Pennzoil Platinum made with natural gas (I still don't understand that one) and it was worse. I'm happy with the Mobil 1 but I think any good oil will do.
Well gents I finally took a look under my truck to check the torque converter to see if the issue was down there in the housing. As time has gone on I have began to believe it's isolated in this area. Its been extremely loud and scary recently. Got much worse the past 2 weeks. Take a look at this s***
(Don't mind the oil, rear main seal replacement was waiting for another tranny drop job)
Was there an issue with cracking flex plates on '02-'04 GMT360's? I could of sworn there was a different p/n for '05 and up. I'm gonna go ahead and order a later year one if that's the case.
(Don't mind the oil, rear main seal replacement was waiting for another tranny drop job)
Was there an issue with cracking flex plates on '02-'04 GMT360's? I could of sworn there was a different p/n for '05 and up. I'm gonna go ahead and order a later year one if that's the case.
This is a kind of Great News (this might be rescued) ... Cautionary Tale News development (or require rebuilding), If you don't mind a baseline technical description as to WHY this has happened... I'd like to render one that will make sense and be a reference point for you in the near future:
Unless Engines are Completely Internally Blue-Printed and Balanced to within a very small fraction of an ounce... they all require a Harmonic Balancer securely fixed to the nose of all crankshafts. The reason for this is that when the Engine RPM climbs... small inputs of vibrations that occur at certain frequencies begin to combine and multiply their forces...which is transmitted LONGITUDINALLY along the entire length of the crankshaft. As Nicola Tesla observed... small, collecting forces can gather to the point of literally shaking an engine to pieces once all of the inputs find a common frequency around which to magnify.
The best way the Automotive Engines in modern vehicles can mediate and solve this problem is to employ massive dual or even triple rings of steel or heavy cast iron that are carefully machine balanced and then nested; one inside the other separated by an Elastomeric Bond. As the forces of the sympathetic "tuned" vibrations collect and get transmitted along the length of the crankshaft... the Harmonic Balancer absorbs these vibrations and "Dampens" them out as the energy passes from the inner ring ...through the Elastomeric rubber bonding and absorbed and dissipated in the larger outer ring.
Now this might seem all too obvious to us all...except there is much more happening here that occurs when all of the longitudinal forces are imparted into the entire crankshaft. As the engine RPM increases...the crankshaft tends to move forwards and backwards when put under a load...resisting the enormous torque in such a manner as it tries to walk itself through the front or the back of the engine. But thankfully, there are two physical components that ordinarily manage to prevent this.
(1) The Harmonic Balancer & Thrust Washer on the front exterior of the Engine
(2) A "Thrust Bearing" that not only has Babbitt bearing material to handle the rotation of the crankshaft ...but this Special bearing has vertical plates attached that serve to prevent most of the Nose to Tail walking of the crankshaft when placed under high RPM or High Torque Loads.
Most of the time... these two engine components manage to harness and control the Fore and Aft motions quite well. However...if the Harmonic Balancer is loosely or incorrectly fastened to the crankshaft...or if the "Thrust Bearing" is badly worn or in some cases... the side vertical pieces needed to fit between the Special Crankshaft Main Journal and the Engine Boss and Main Cap... occasionally ... They will just snap off and drop to bottom of the Oil Pan... and after that... very bad things will begin to happen inside the engine as well as outside at the attachment point of the Flex-Plate and Torque Converter.
If this problem of bearing surface loss or those "side wings" snap-off happens...the crankshaft will move violently longitudinally...slamming the crankshaft journals against both sides of the rotating assembly of the Connecting Rods and allow them to rub up against the interface in between the base of each connecting rod...and the interior flutes and counterweight upright portions of the the crankshaft itself. This will cause friction and excessive heat that will cause these components to heat up hot enough to turn blue or black and can get smoking hot... causing journal bearings to seize. The pistons can also be affected, as their rods are flexing at the bottom from left and right and then back again... this will cause side loads on the wrist pins and on their internal bronze bushings. The pistons will likewise be canted inside their cylinder bores and can rock back and forth instead of the up and down with a stable and steady vector line of forces being applied in an essentially straight line up and down. These other motions will serve to either wear out or break components as well.
On the outside the engine, we finally get to the artefact that you discovered as Cracks in the Webbing of the Flex-Plate, which you will later find began as closer cracks around the bolt holes and centre area where the Flex-Plate is bolted to the tail piece of the crankshaft. You can visualize this problem by taking a #2 Pencil... Poking a hole in the middle of an Aluminum Pie Pan...and after securing the Eraser end of the Pencil taped dead centre in the Pie Pan...lay it with the hollow area face down on your counter top and while hold down the "Flex-Plate" Pie Pan.... simply pull up and down on the Pencil "Crankshaft" and watch how easily the Pie Pan flexes into a cone shape...moving from concave to convex and changing its shape while the metal in centre is being tortured by this repetitive flexing motion. There is absolutely no difference between this analogy...and the cracked Flex-Plate at the back of your engine.
Unfortunately... even if you replace the Flex-Plate now and continue to drive as before with no changes in the way that is being done... When enough of this "Flexing" has done with sufficient repetitive motions back and forth to work harden, fatigue and crystallize the metal at its contact fastener points... then new cracks will begin to propagate outwards and the Flex-Plate noises will return like the Prodigal Son. The only way to mitigate this...is either rebuilding the "Bottom-End" either by having someone confident enough to pull the Oil Pan and work on just the Thrust Bearing from below...or the engine will have to be pulled and repaired on an Engine Stand.
I'm very sorry for this the reality... I wish it were otherwise... but perhaps there might be a Silver lining in all of this if you can locate an inexpensive low mileage replacement engine from a recently wrecked, but otherwise well-cared for vehicle that has an Engine In Good Shape. You will have to decide soon... because now that the Flex-Plate is essentially being help up by the (3) Torque Converter Bolts...the vibrational separation damage will begin to extend into the transmission as the TC "O" rings...wear out or cut and Transmission Fluid begins dripping out.
Unless Engines are Completely Internally Blue-Printed and Balanced to within a very small fraction of an ounce... they all require a Harmonic Balancer securely fixed to the nose of all crankshafts. The reason for this is that when the Engine RPM climbs... small inputs of vibrations that occur at certain frequencies begin to combine and multiply their forces...which is transmitted LONGITUDINALLY along the entire length of the crankshaft. As Nicola Tesla observed... small, collecting forces can gather to the point of literally shaking an engine to pieces once all of the inputs find a common frequency around which to magnify.
The best way the Automotive Engines in modern vehicles can mediate and solve this problem is to employ massive dual or even triple rings of steel or heavy cast iron that are carefully machine balanced and then nested; one inside the other separated by an Elastomeric Bond. As the forces of the sympathetic "tuned" vibrations collect and get transmitted along the length of the crankshaft... the Harmonic Balancer absorbs these vibrations and "Dampens" them out as the energy passes from the inner ring ...through the Elastomeric rubber bonding and absorbed and dissipated in the larger outer ring.
Now this might seem all too obvious to us all...except there is much more happening here that occurs when all of the longitudinal forces are imparted into the entire crankshaft. As the engine RPM increases...the crankshaft tends to move forwards and backwards when put under a load...resisting the enormous torque in such a manner as it tries to walk itself through the front or the back of the engine. But thankfully, there are two physical components that ordinarily manage to prevent this.
(1) The Harmonic Balancer & Thrust Washer on the front exterior of the Engine
(2) A "Thrust Bearing" that not only has Babbitt bearing material to handle the rotation of the crankshaft ...but this Special bearing has vertical plates attached that serve to prevent most of the Nose to Tail walking of the crankshaft when placed under high RPM or High Torque Loads.
Most of the time... these two engine components manage to harness and control the Fore and Aft motions quite well. However...if the Harmonic Balancer is loosely or incorrectly fastened to the crankshaft...or if the "Thrust Bearing" is badly worn or in some cases... the side vertical pieces needed to fit between the Special Crankshaft Main Journal and the Engine Boss and Main Cap... occasionally ... They will just snap off and drop to bottom of the Oil Pan... and after that... very bad things will begin to happen inside the engine as well as outside at the attachment point of the Flex-Plate and Torque Converter.
If this problem of bearing surface loss or those "side wings" snap-off happens...the crankshaft will move violently longitudinally...slamming the crankshaft journals against both sides of the rotating assembly of the Connecting Rods and allow them to rub up against the interface in between the base of each connecting rod...and the interior flutes and counterweight upright portions of the the crankshaft itself. This will cause friction and excessive heat that will cause these components to heat up hot enough to turn blue or black and can get smoking hot... causing journal bearings to seize. The pistons can also be affected, as their rods are flexing at the bottom from left and right and then back again... this will cause side loads on the wrist pins and on their internal bronze bushings. The pistons will likewise be canted inside their cylinder bores and can rock back and forth instead of the up and down with a stable and steady vector line of forces being applied in an essentially straight line up and down. These other motions will serve to either wear out or break components as well.
On the outside the engine, we finally get to the artefact that you discovered as Cracks in the Webbing of the Flex-Plate, which you will later find began as closer cracks around the bolt holes and centre area where the Flex-Plate is bolted to the tail piece of the crankshaft. You can visualize this problem by taking a #2 Pencil... Poking a hole in the middle of an Aluminum Pie Pan...and after securing the Eraser end of the Pencil taped dead centre in the Pie Pan...lay it with the hollow area face down on your counter top and while hold down the "Flex-Plate" Pie Pan.... simply pull up and down on the Pencil "Crankshaft" and watch how easily the Pie Pan flexes into a cone shape...moving from concave to convex and changing its shape while the metal in centre is being tortured by this repetitive flexing motion. There is absolutely no difference between this analogy...and the cracked Flex-Plate at the back of your engine.
Unfortunately... even if you replace the Flex-Plate now and continue to drive as before with no changes in the way that is being done... When enough of this "Flexing" has done with sufficient repetitive motions back and forth to work harden, fatigue and crystallize the metal at its contact fastener points... then new cracks will begin to propagate outwards and the Flex-Plate noises will return like the Prodigal Son. The only way to mitigate this...is either rebuilding the "Bottom-End" either by having someone confident enough to pull the Oil Pan and work on just the Thrust Bearing from below...or the engine will have to be pulled and repaired on an Engine Stand.
I'm very sorry for this the reality... I wish it were otherwise... but perhaps there might be a Silver lining in all of this if you can locate an inexpensive low mileage replacement engine from a recently wrecked, but otherwise well-cared for vehicle that has an Engine In Good Shape. You will have to decide soon... because now that the Flex-Plate is essentially being help up by the (3) Torque Converter Bolts...the vibrational separation damage will begin to extend into the transmission as the TC "O" rings...wear out or cut and Transmission Fluid begins dripping out.
Last edited:
Sparky
Member
- Dec 4, 2011
- 12,927
Let's not jump to conclusions. I know of a lot of people (on various platforms) who have simply replaced their flexplate and never had an issue again. Sometimes, it can just fail.
My 02 never did for whatever that is worth and I haven't heard of it being a routine issue on older engines. Not sure what changed between 04 and 05, and not sure if they're interchangeable.
My 02 never did for whatever that is worth and I haven't heard of it being a routine issue on older engines. Not sure what changed between 04 and 05, and not sure if they're interchangeable.
Turns out it was like 2006 or 2007 and later that had the redesign. It didn't look like it'd work spacially, so I found a used $30 one that looked in great shape from an '05 Voy. It'll be here next week. The flexplate's are not easy to find for our platform (w/ 4.2's), not in stock even on rockauto or GM part sites. Couldn't even find a proper p/n. EBay was my only luck last night.
I looked at a video on YouTube of a TB with a cracked flexplate and it was on par with the noise I am having.
This was another member’s experience with this identical problem… and I made the same observations that involve a sound understanding of the physical forces and mechanical problems that lead up this occurrence ...and just as in this latest incident... without one scintilla of “jumping” to any conclusions. And for the record... though I was no more happy about the truth of it then than am I about @Capote ‘s present difficulties... I asked this member to prepare himself for the very real possibility that his next Flex-Plate might repeat the problem by Cracking and Failing...
Nov 13, 2015 #6
crazyelvis3577 Member
Messages:
16
Likes Received:
5
I'm thinking that when the old transmission failed (probably due to lack of maintenance before I got it) after I heard a thud like a band or gears break that it caused unnecessary stress on the flex plate and then me trying to get it to go to get out of the middle of the road was also a factor in that unnecessary stress. I have checked the crank for end play and such and everything seems to be within specs. So, hopefully I got lucky on it, but only time will tell. I drove it forever before the original transmission failed (with no problems or noises) and since the new transmission I drove it a lot before I even heard a noise from the flex plate. Would it actually take that long for a flex plate to make noise being driven if those are so easily broken?... Like I said, I'm thinking that whatever happened when the original transmission failed and I heard that thud something internal in the trans locked up and then with me revving it trying to get it out of the road may have started the crack. I'm hoping that's the case anyway.
... and this was his unfortunate follow-up response 12 days after he pulled the transmission and replaced the Cracked Flex-Plate with a Brand New OEM one:
Nov 24, 2015 #8
crazyelvis3577 Member
Messages:
16
Likes Received:
5
So I started having the same issue again, removed inspection cover and the flex plate is cracked in the same place as the old one just not quiet as bad, yet. I went and bought a low mileage engine to I'll be swapping that in a few days. The new engine I bought looks good and the flex plate looks good, luckily somebody had already removed the transmission so we will give this a go.
When it comes to making observations, descriptions of mechanical operational properties and their physics and my recommendations for repairs… my Half-Century of Experience as a Mechanic has taught me to be considerate enough to NEVER
“...jump to any conclusions...”
Last edited:
therealsethallen
Member
I'm going to agree with Sparky on this one. I've seen a small number of GMT360s with this issue, and for whatever reason it's typically after the tranny has been removed or reinstalled poorly, or it ripped apart by someone with the mechanical skills of a toddler. I'd say if you've isolated it to a flex plate, replace it and see what happens. It's an uncommon failure.
I'm going to disagree with @MRRSM on this one and his "Catastrophic Failure" theory is really kind of a load of crap, not everything requires ripping the engine apart, and not everything requires throwing hundreds (maybe even thousands) of dollars of parts for a possibility. The original owner of my Volvo put a in flexplate 86k miles and it went to nearly 233k without issue.
I'm going to disagree with @MRRSM on this one and his "Catastrophic Failure" theory is really kind of a load of crap, not everything requires ripping the engine apart, and not everything requires throwing hundreds (maybe even thousands) of dollars of parts for a possibility. The original owner of my Volvo put a in flexplate 86k miles and it went to nearly 233k without issue.
Last edited:
Mooseman
Moderator
As if the engine itself would be the cause is kinda ludicrous IMHO. Possibly an issue with the torque converter might.
Don't throw out the baby with the bath water.
Don't throw out the baby with the bath water.
Sparky
Member
- Dec 4, 2011
- 12,927
@Capote did have his tranny out a few times if I recall correctly - very possible (probable?) something one of those times happened to the plate after mounting/dismounting so many times. That's why I said to not jump to blaming the engine right away, given the transmission history.
Well By God, Seth... I hope your right and in this instance especially... I really do hope that I'm wrong here and NOT a Doomsayer vs. @Capote... He needs that truck up and running... I have also considered that @Sparky might be correct in this instance if the following circumstances described in this video are the alternative answer as the cause of the problem.
I was simply regaling an actual event that happened here on GMT Nation and in that case... there certainly wasn't any wild guesswork on my part as to what was causing the problem. I suppose you'll have to take a swing at my chin for bristling so badly about it... but a Man has to jealously guard his Mechanical Chops from time to time. Anyway.. Please have a look at this video and let me know what you think:
Last edited:
Again... I'm not making this stuff up. Watch how the Crankshaft pushes and pulls back and forth against the Flex-Plate. What we can't see here though due to the RED TC being in the way, is how much of that "Coning Effect" is really taking place pushing in and out near the centre of the Flex-Plate bolt up flange stressing and work hardening the mild steel....Seeing is Believing:
And in support of @Mooseman 's efforts to Tackle me before I throw out my Baby ... (Slooooow Down There Bobby...LOL)... This Torque Converter issue actually looks like a very promising thing to investigate!
... and more support for @Mooseman's impression of it NOT being internal engine bearing issue... noting how completely FUBAR'd the Center Bolt Up Flange area was... and a Missing TC Fastener:
Last edited:
Yeah I've had my transmission out 3 times already. This'll be 4 times now. Torque Converter is a remanufactured one.
Everyone, let's not make this thread into a pissing match. We're better than that, everyone has opinions and input. Just respect what the other says, whether or not you agree. Thanks
- Status