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Rod knock? Engine toaat? w/ video

acschilling

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92 4.0 183,xxxx. Aftermarket heads installed in Mid-March. Have needed to add a quart of oil every 200-300 miles. For years the lifters would tick but quiet when warmed up. Last night constant ticking started, even when warm and at idle. And this morning it just got worse. Is this rod knock? Sounds pretty wicked. She toast?

 


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Wolfie_85

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My valvetrain was always noisy. This noise does not sound like that. Just a bit of light ticking until it warmed up. Does the noise decrease when warmed up?

Mine got to the point where it burned a quart every 150 miles. Then one day she puked oil out of the dipstick tube and that was that. Didn't stay running. If you have no major leaks, it's probably burning the oil. Notice any blue smoke from the exhaust? Any blowby? It could be bad rings. Oil loss can also be caused by a bad PCV valve, but that doesn't answer any questions about the noise.
 




natenkiki2004

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From what I've heard, rod knock can come and go, depending on load and RPM. I really want to say yours sounds like lifter tick, like a lifter is totally stuck and not pumping up at all. Not the regular tick that most of us experience. Does it run rough at idle? If so, I'd lean more towards a stuck lifter since that prevents the cylinder from breathing properly.

Couple things I'd try if I were in your shoes, I'd warm the engine up at idle, not revving and see how it sounds. If the sound doesn't change, stick an oil pressure gauge on it and see where you're at. If it's normal then it's gotta be a lifter not pumping up or, much less likely, the rocker arm shaft is loose (bolts not tight).
 








acschilling

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My valvetrain was always noisy. This noise does not sound like that. Just a bit of light ticking until it warmed up. Does the noise decrease when warmed up?

Mine got to the point where it burned a quart every 150 miles. Then one day she puked oil out of the dipstick tube and that was that. Didn't stay running. If you have no major leaks, it's probably burning the oil. Notice any blue smoke from the exhaust? Any blowby? It could be bad rings. Oil loss can also be caused by a bad PCV valve, but that doesn't answer any questions about the noise.

It drips a little bit of oil, maybe leaves a quarter sized spot on the ground when parked; doesn't seem like enough to be the culprit of losing all that oil. It doesn't smoke at all on start up, just maybe a bit of moisture from condensation on the exhaust; coolant level has been steady. If it burns while I'm driving, I can't notice; but it's disappearing like crazy. 5 quarts a month roughly. I've felt what seems like excess engine heat getting into the cabin..no heater on (summer obviously), just excess ambient heat from the engine. The gauge would climb into the "O"-"R" range but never overheat. With how much we know our trucks, we know when the engine feels hotter than its been or probably should be..you know what I mean? Rod bearing heating up maybe?
 




acschilling

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It sounds like a lifter to me, as well. A rod would be more of a "knock" than what I can hear on the video.

Sorry for the weak audio..dropped my phone in a bucket of wood stain about a year ago. Listening to music on it sucks too. I made another video, this one is about 3 mins long, engine warmed up. Towards the end I rev the engine to sound 2000rpm and it doesn't sound good. Pretty sure it's not just a lifter. Like the connecting rod now has slack making it knock. Lifters will quiet..this just sounds deathly.
 




2stroke

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It does sound a bit like a lifter, especially with the hot idle, but its so hard to tell sounds over a video. Actually the first thing that came to mind was a flex plate problem, especially since I get a hint of a squeeking sound.
 




Turdle

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With the engine running at idle, pull spark plug wires off the coilpack one at a time. See if the "knock" goes away when the combustion is removed from the ticking cylinder. As long as you pull them off the coilpack quickly and place them back quickly you will not get shocked. trust me.


If the sound does go away with a wire pulled, make a note of which cylinder it is, as, it might be a rod bearing, and it is knocking when the combustion happens.
Also note if the ticking goes in rhythm with the arcing spark you created. If it does, it is valve train related.


The "rhythm" of the knocking seems to be "half speed" of the engine to me, which would indicate a lifter-rocker arm-pushrod problem. A worn rod bearing usually taps very fast. Keep in mind, the engine rotates 2 times the speed of the camshaft, so valvetrain noises "knock" at a slower rate than a rod bearing.

edit
a bent push rod, collapsed lifter, broken rocker arm, or sticking valve will cause a huge amount of slop, which can sound like someone trying to escape from inside the engine with a hammer. Heck, it could even be a huge amount of carbon buildup.

A little trans fluid sucked into the intake via a vacuum line, left to sit overnite followed by A seafoam treatment might do wonders for this.
I had a friend who broke down and bawled when his prize chevy truck made a knocking noise. He swore it was a rod.
alocal mechanic ran some trans fluid into it, let it sit overnight and seafomed it. There must have been a carbon deposit in a valve seat which did not allow the valve to completely close, causing a knock due to the slop in the rocker arm-pushrod, because after burning out the gunk the noise went away. He still drives this truck to this day.
 




natenkiki2004

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Turdle is spot on and I agree with 2stroke, it sounds more like a lifter in the 2nd video. It sounds VERY close to my lifter tick. I'd try what Turdle said and if nothing changes, pull the valvecovers off and inspect the pushrods & rockers. No need for disassembly, just see and feel for slop, peek at the lifters.
 




malohnes

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Turdles comment on tranny fluid/seafoam is spot on. The key is to make sure the engine is good and warm so cooldown and overnight soaking does the cleaning trick.

I did this treatment when doing a top end rebuild a few years back, only I dumped all my engine fluid after warm up and pour straight tranny fluid in, ran at idle for a minute and then soaked for several days. Parts came very clean after that. Took a couple oil changes to clear out the gunk.
 




acschilling

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Thank you! Latest developments: yesterday after reading what y'all thought I went back out and let it idle for a good 30 mins and let it bang around, giving it gas here and there up to 2500 rpm. The sound became really unnerving, changing pitch all over the place! Then it got quieter and quieter until finally the sound was gone. Weird. Shut it down. Turn it back on an hour two later. Sounds is back but much quieter and much more indicative of a lifter tick. Okay, that's better. Today letting it idle, it ticks the same, much quieter and a lot like lifters. Only my experience before with lifters is that they start loud, and begin a rhythmic ticking, starting and stopping in a loop until it's warms most of the way and nearly disappears; only now it's just a constant, steady tick. I'll give the Seafoam and tranny fluid a go. I'm usually always happy with Seafoam results.

Just not sure where all the oil is going! 200-300 then oil light comes on. The laundry list of things I've done since the heads over the past few months is ridiculous...almost embarrassing. I was hesitant to originally share.
 




acschilling

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I was just thinking...if I take the valve covers off and pour like a quart of oil down each side will that be a good test to see if the valve seals are sealing? Wouldn't it smoke like crazy on start up?
 




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