2013 Tahoe LS top end noise

I've got lifter/rocker noise on passengers side. I've recently done a top end clean, to remove carbon that was causing my exhaust valve on cylinder#2 to stick at low rpm. It worked, I no longer have a misfire. About 3 days later I started getting a light tapping sound. I thought I needed to change the oil but it had not been over due. It run full synthetic. The next day or got louder and before I changed the oil I thought I'd remove the valve cover to do a visual inspection. Although all of the rocker arms bolts are completely tight I've found that I have play in my #2 front valve (intake I think) and #4 front valve. I recently pulled the valve springs (intake and exhaust) on #2 only to inspect them but didn't touch #4 so it's not from the inspection. I can move the push rods up and down a bit on those 2 rockers. From reading I've come to the conclusion that I should do an engine flush to remove any carbon deposits that may have come loose and might be clogging the oil for through the lifters/push rods and then do an oil change of course. Does anyone have any advice? Is there any other adjustment? I know there is supposed to be a little play but this seems a little too much. I was wondering about the "plungers" if they go bad or an I over thinking this? I appreciate any help

Just00Jake said:

I've got lifter/rocker noise on passengers side. I've recently done a top end clean, to remove carbon that was causing my exhaust valve on cylinder#2 to stick at low rpm. It worked, I no longer have a misfire. About 3 days later I started getting a light tapping sound. I thought I needed to change the oil but it had not been over due. It run full synthetic. The next day or got louder and before I changed the oil I thought I'd remove the valve cover to do a visual inspection. Although all of the rocker arms bolts are completely tight I've found that I have play in my #2 front valve (intake I think) and #4 front valve. I recently pulled the valve springs (intake and exhaust) on #2 only to inspect them but didn't touch #4 so it's not from the inspection. I can move the push rods up and down a bit on those 2 rockers. From reading I've come to the conclusion that I should do an engine flush to remove any carbon deposits that may have come loose and might be clogging the oil for through the lifters/push rods and then do an oil change of course. Does anyone have any advice? Is there any other adjustment? I know there is supposed to be a little play but this seems a little too much. I was wondering about the "plungers" if they go bad or an I over thinking this? I appreciate any help

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It's okay to run the engine with the valve covers off for a minute to see what's going on. What you're looking for is any that aren't moving when they should be. Post up a video using a YouTube link and we can give it a listen as well. Your theory is plausible but I'd caution about the engine flush. You can trigger problems with the AFM system that way.

Geotrash said:

It's okay to run the engine with the valve covers off for a minute to see what's going on. What you're looking for is any that aren't moving when they should be. Post up a video using a YouTube link and we can give it a listen as well. Your theory is plausible but I'd caution about the engine flush. You can trigger problems with the AFM system that way.

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Well I don't know if I have "AFM" or "DOD" but I do know how to check, I'm embarrassed to say that once I learned how to check if it was present I've had so much else to demand my attention. I did pull the valve cover and inspect the push rods and they are fine. Even wear and in good shape. I double checked the torque on the rocker bolts and they were good. I did end up doing the engine flush and after I let it drain for a while. I filled it with a quart of Lucas oil treatment and 5 quarts of Full Synthetic 5/30 oil. It did seem to quiet a little but no where near normal. I will absolutely record a video tomorrow to allow you to hear it and see it. I appreciate the help

Any chance there's a loose spark plug or loose/broken exhaust manifold bolt? Either can make some strange noises. Get a 2 or 3' piece of hose (garden hose works fine) to use as a stethescope, one end at your ear, other end use as a microphone to pin point noise if external.

or "mechanic stethescope" at HF ($6), amazon, ebay, o'reilly, etc

I appreciate the input and apologize for the delay responding. The day after I posted, I was helping a buddy who had a truck on a trailer, with the tongue being held up by a jack that was only half on it. So he wanted to lift up the tongue and reset the jack so I had an 8 foot 2x4 standing waiting for him. The 2x4 was under the raised tongue but not touching it. I was holding in 1 hand waiting for him to be in position before doing anything. BUT, maybe 3 seconds before he got there, he was another person hopped up on the back of the trailer to get something (completely unexpected) so the Jack shifted, the trailer fell off the jack and came down on the 2x4 (I didn't even need to be holding yet) It of course came right out of my hand and by some bad luck, slammed down across all 10 of my toes, I breaking both big toes and 2nd toes and blowing a hole out of the side of my left big toe. It was messy and very painful although I'm glad I didn't lose any toes. Had a friend drop some shine off for pain. I lost half of my left ring finger in my 22 years in construction but that's it. I am going to post a video today of the motor running with the passenger side valve cover off as you requested, and I'll wait for an opinion, after a load of reading time on my hands, I'm leaning towards collapsed/stuck lifter. And it's on #2, so I can't even consider trying to go through the ports under the intake that are only on the AFM lifters to try to free it if it's just stuck. I did have a question though... This whole issue only popped up about 100 miles after doing a top end engine clean. Through the intake (in case there were other methods). What could this have done to cause my problem? Video to be posted asap for review. Thanks again

@Just00Jake Glad you're ok man. Its possible the top end cleaning released some large pieces that got stuck in an oil passage and messed something up or it could just be coincidence.

In any case it would be worth your time to tear the engine down and inspect the camshaft, if the camshaft or lifter has damage then "freeing" up the lifter is only buying you borrowed time.

I look forward to the video before jumping to conclusions but do it right or do it twice.

Just00Jake said:

Well I don't know if I have "AFM" or "DOD" but I do know how to check, I'm embarrassed to say that once I learned how to check if it was present I've had so much else to demand my attention. I did pull the valve cover and inspect the push rods and they are fine. Even wear and in good shape. I double checked the torque on the rocker bolts and they were good. I did end up doing the engine flush and after I let it drain for a while. I filled it with a quart of Lucas oil treatment and 5 quarts of Full Synthetic 5/30 oil. It did seem to quiet a little but no where near normal. I will absolutely record a video tomorrow to allow you to hear it and see it. I appreciate the help

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Here is the video. Hopefully it's viewable. I was not able to notice on the video but in person the tapping noise cut down to about half as loud as it was when I first started it

Just00Jake said:

Here is the video. Hopefully it's viewable. I was not able to notice on the video but in person the tapping noise cut down to about half as loud as it was when I first started it

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Sure sounds like a lifter to my ear