Thank you so much for this video! my lifters were tapping and the mechanic was going to charge us 2500 to fix it - I showed this video to my husband he watched it several times -,followed it and fixed our problem for just $75! thanks for all your help

Master mechanic here 44 yrs experience. First off let me say I like the man in the video, I like his attitude. But here is my first analysis from the start of the vid is OIL PRESSURE, next after that valve cover was removed I saw NO OIL laying in the upper cupped area of the rockers! Meaning the rockers aren't getting oil and of course the lifters cannot get oil either being no oil gets to the top in order to drain down! The sound I also heard at the vid start was not lifter noise but rocker tappet noise. That engine is not getting upper oil! Oil pump issue here! Thanks

My 2008 Tahoe sounded even worse than this one. I did everything that you did, except didn't pull the rods, just shot some Seafoam engine down the rods a few times, put her back together, added a little motor flush to the crank case, let it idle for about 10 minus then took a freeway drive for about 30 minutes, punching the gas here and there to force through whatever was blocking the oil flow, and NO ticking, pinging whatever you want to call it. 100% FIXED. Idle was rough prior to this and has been reduced by about 40-50% too. Saved myself a $3000 repair bill I couldn't afford. Totally stoked. Thanks for this video. BTW, I'm handy but never have done anything with an engine before, not even an oil change, so anyone with some patience and the right tools can do it given the proper motivation.

I don't know about the methods in this video... but I do know this... the poster in the comment section who suggested MMO (Marvel Mystery Oil) this "issshhhh" is on point. Added a quart to the oil in my 2005 Chevy Tahoe 5.3L (180K miles) that had lifter noise. Also added 12 oz. to a full tank of gas... After adding I allowed the vehicle to run idle for approx. 10-15min... then drove the vehicle for approx. 30 min and to my surprise the oil pressure ran at 30-35 psi idle and 40 psi while driving. Guess what, no lifter noise at all... the noise was gone by the time I arrived home. You can pick up a 1 quart bottle at Walmart for $3.88... Cheapest quick fix ever... I will be using this with every oil change and every other fill-up in the gas tank...

Brian- I had this issue, and following this video I meticulously cleaned every lifter and pushrod in the engine. The lifter noise stopped...for about 50 miles. I then discovered that recently GM issued a bulletin on lifter noise problems on the 5.3. Apparently, the o-ring on the oil pick-up tube, where it meets the block, flattens out and it starts sucking air, decreasing oil flow to the top of the engine. Results: lifter noise. I replaced the o-ring, sure enough, problem solved.

Reminds me of back in the nineties, 265 Valiant, Ausse version. Spray carb cleaner down beside the pushrod onto the hydraulic lifter at idle, did the job. Recall using a bit of ATF in the oil, gunked up Rover V8, (had sat for years) cleaned the crap out after we preprimed the motor, ahh, the memories.

2006 Envoy, same exact cylinder as your video. I did exactly as you suggested, except I didn't have to pull the rockers. I could easily see that the lifter was low and allowing the pushrod to be loose. I was able to put the straw straight through the rocker into the pushrod. Replaced the valve cover, flushed the engine with motor medic by Gunk. Fifteen seconds into starting the engine it quit tapping. oil change and it's all good. Thanks for the video, I'm actually kinda stunned that it was this easy.

I have a 2004 5.3 8:58 Yukon that had a very loud tick passenger side- this worked for me- after the motor flush and B-12 truck runs quiet! Saved me a lot of money- this was my last shot before having the lifters replaced! Thank you!!

I know this is old but you're still helping people and I really appreciate man!

Great video Brian! Suggestion: Use this sequence to clean the crud out of the lifters - 1. Solvent (Berryman, Gumout, etc.) 2. Light spray Oil (PB Blaster, Liquid Wrench, WD-40, etc.) 3. Rubber tipped air gun on the push rod ends to blow the crud away. Repeat the sequence 3 or 4 times, and of course change the engine oil & filter when you're done. The solvent is great at dissolving the crud, but the oil has enough viscosity to carry the crud away. Adding the light oil and compressed air really clears it out. Thanks.

Thanks. Brian, I hope you show more videos effective like this video. I drive 2010 escalade esv V8. this week I got a noise from passenger side. tapping sound. then, I got a invoice for 3,600 dollars for repair from auto repair shop. I do not know how much value left for my 12 years old vehicle. but 3,600 dollars is too much for me. I watched 20+ youtube videos. this video is best of best. and it works with 15 dollars instead of 3,600 dollars. I do not know why auto repair shop do not suggest this method first. it is worthy to try and save cost significantly. what I did is that. (1) I sprayed B12 Chemtool in the hole, where tapping sound, it was #6 passenger side. (2) assemble cover back to original place. I leave it 1-2 hours or so. (3) pour 1L motor push & 5min & 2K RPM 2min, still tapping, 2K RPM 2times more. (4) change new engine oil 5L + transmission oil 1L. + oil filter change (5) nothing changed, still tapping, (6) 8 hours passed, tapping sound gone. I spend 6 dollars B12 Chemtool + 9 dollars Motor Flush, total 15 dollars instead of 3,600 invoice. this video save money, and when there is no tapping anymore, I feel exciting, it was embrassing extra budget request this week. but with this video, I enjoyed. thanks again.

THANK YOU SIR. I LOVE people like U. Guess what I did this weekend, I thought it was the water pump. Spent $200 new pump, hoses and anti-freeze. started her up and to no avail, the tapping was still present. To me, not all was loss cause now my cooling system is in tip top summer shape. it's ready for those 110 degree days stuck in traffic. OH YEAH. THANKS Im a new subscriber now

Brian your videos are awesome, if I may offer a suggestion to help you avoid future headaches: tape the straw to the applicator nozzle before spraying that way you wont lose the straw down into the engine if there is a blow out between the nozzle and straw

Lifter cleaning: Use the pushrod as a "straw" to *directly inject* the cleaning fluid, AND to *push the lifter down to work it*, pumping the cleaner through it. IMO K1 Clear Kerosene is a great "flushing" fluid; drain 2 QTS oil, replace with same amount of K1 CLEAR Kerosene (not the cheap pink colored). Also- to check for a bent pushrod- clean, then roll them slowly by hand on a piece of quality window glass. *OLD SCHOOL STUFF.*

My 5.3 with 300,000+ miles developed a major lifter tick. I changed the oil, replacing one quart of oil with a quart of Rislone. The the tick cleared up. Cleaning oil passages/lifters is the goal and I think this product did that for my engine. I was relieved, replacing lifters on a 5.3 is not an easy fix.

I know this is an old video but wanted to add my experience. I have an 09 Yukon that sounded EXACTLY like the truck in this video but mine was very hit or miss, no rhyme or reason to when or why it would start ticking. Before taking off the valve covers and doing this in my truck i decided to try a different kind of flush. I changed the oil and put a K&N filter on, put in 5 qts. of 5w-30 full synthetic (whatever was on sale) and 1 qt. of automatic transmission fluid. The minute i started it you could hear the difference in the engine, smoother, quieter and not a tick to be heard. The day after i did this it was actually -5 when I got up to go to work and the cold start didn't even knock/ping or tap like it used to, smooth as butter. Before this my oil pressure would be at or just below 20 at idle and 30ish on the highway, would jump to 40 if a floored it. Afterwards, idle oil pressure was just above 30 and about 39 on the highway. I drove it like this for 200-300 miles and did a full oil change with a new K&N filter, 5.5 qts of 5W-30 Royal Purple and .5 qts of marvel mystery oil and have done this each oil change since and the tick has never returned. Hope you all have good luck with your experiences! Thank you Brian for the video, gave me the info I needed to try and tackle the problem myself.

Great video but wanted to share my experience. My 2005 Tahoe 5.3L had a ticking valve. The first or second valve on the drivers side. Would come and go but very irritating. I replace the valve cover on that side and tried the Chemtool spray to no avail. The problem is the O-ring on the oil pickup tube in the oil pan. I dropped the oil pan and found the o-ring was cracked which was causing lower oil pressure and the oil not to travel to the front lifters. I replaced it and no more ticking.

I had the same thing happen to my truck, but I put half a can of seafoam in it and drove it for a hundred miles and did a oil change and that stuff really worked great. It was running smoother, quieter, and there was a lot less crank time.

ive done this method on kohler command v twins with hyd lifters.....people never change the oil in their lawn equipment and when the oil gets like petroleum jelly hyd lifters no workie like they supposed to!!! great video brian!!!!

I have a 05 Sierra with a 270.000 miles on it and i swear you can't here it idol. It's still very very quiet. I just kept the oil change every 2000 miles or less. It's worth it to me.

11:46 getting excited about spraying. was waiting for the little red tube to pop off and fall into the push rod hole.

You're right. You can't please everyone. I don't expect to. I love myself and that's enough for me.

My 2000 Suburban is making the same noise.After watching this video several times I finally got bold enough to pull my valve cover off. OMG the sludge was so thick I used 5 cans of the B12. I used the flush 2 times changing the oil and filter each time the noise is much better and my oil pressure is almost back to normal. Thank you so much for posting this video.

Awesome video! After spraying you should drain all old oil, tighten drain bolt, pour the flush DIRECTLY on the lifters and let it soak for a little before pouring good oil over them. Button up the valve cover. Then fill as normal and do the recommended flush instructions

Absolutely the best explanation I have found on KZfaq! I have been stressing over this problem with a new truck I bought thinking I made a huge mistake. Thanks Brian for this very helpful video!!!

Problem was the O ring on the pick up tube. Thanks for your video and thanks to your posters. My Buddy and I recently fixed his noisy 5.3. It had the same noise as in your video. It was louder during load while going up a hill. It was the O ring located on the pick up tube. It was cracked and came out in two pieces. There was no way it could have been allowing oil pump to efficiently operate. Factory oil pan gasket and O ring were very reasonable. Problem solved. Not a hard job. Probably a 2 - 3 hour job.

He was 4,518 miles after his previous oil change. If the last oil change was with a quality full synthetic motor oil and less than a year ago, he should be totally fine. If the oil was a crappy conventional motor oil, yeah 3,000 miles max. That’s why I do all my own oil changes. None of this “paying for a full syn oil change and getting conventional oil gumming up my motor” crap. Great idea man with the B12 and the motor flush to clear that crud out of the lifter and free up the small piston inside it!

I just bought my first truck, a 2002 Tahoe LS and had the same issue in the same location. I was only about 500 miles overdue for an oil change and got it the next day after buying it. I also ran some Seafoam through the crankcase as well as the tank. Very quiet afterwards but I would still like to drill deeper and check my lifters as well. Thanks for recommending good products as well. #subbed

Amazing Results!!! I do most of the work on my own vehicles, but I'm pretty hesitant to get inside the engine. My 2005 Suburban suffered from increasing ticking...it started out a small periodic tick and became a noisy tick I could hear when driving on the freeway. It was getting worse and worse. So, I was about to bite the bullet and take it in for whatever the mechanic had to do. this was not an exciting prospect. Would it cost $500? $1000? More? When I saw this video, it gave me hope. I went and bought the carb cleaner and engine flush, followed the exact steps laid out in the video. After the oil change, I was surprised that there was no more noise, but figured that might be due to idling and the new oil. The real test came when I took a drive to a nearby city on the freeway pulling a trailer. Loads usually induce the racket if nothing else does. No Noise! After a half hour on the freeway and 20 minutes of city driving, I heard a very slight tick once while idling. I think I'll do the flush again at the next oil change. Total cost: Under $10 besides normal oil change. I'm so happy! Thanks for this great video.

I've slowly been watching all of your uploads as I have time and I must say, you are the absolute MAN! Watching you and others like you, (ErictheCarGuy), really restore my pride in being a Tech. You guys show people there are honest guys out there and they do great work. I also appreciate the fact that you also mini-reviewed the products you used. I love Sea-Foam and B-12 is fantastic. I never had too much of a belief for any motor flush working, but you convinced me. Thanks bro

About motor flush: Lots and lots of people who actually sell motor flush products and additives told me never to use them. Motor flush usually softens the seals and creates leaks or knocks. For cleaning the inside of an engine, the best thing I use is plain motor oil. Buy some cheap oil, put it in, run it for a few days and then dump it. Put some quality stuff in it. Did that on my dad's 1.8l Ford, it has 17 years and around 300k km and it runs great. I'm so doing the same thing on my van.

You didn't do anything wrong in my opinion. I just found a longer straw that reached into the lifter... fill em full... that stuff evaporates anyway, I did an entire can for all the lifters and my Dad's 5.3 it don't clack anymore. Wish we had known all this in the 80's but lifters were cheap back then. Great Video!

Thank you Brian, my 07 silverado with a 4.8 was making the same noise, started when under acceleration then within a week would tick at idle. It seemed to be coming from the # 2 exhaust so I did the motor flush, being it the least intrusive, then the chemtool and in 50 miles the tick was gone. Thank you so much.

I just had a collapsed lifter replaced in my Chevy 5.3 with only 6k miles on the clock. Actually two lifters replaced, as GM said the opposing cylinder lifter had to be replaced too. Great that this was 100% warranty, sucks that it happened at all.

Have used this method to flush Mazda 1.6 and 1.8 Liter engines that can often suffer from loud lifter tap if not run for a long time, or bad oil changes.. Should work well in any engine really. get engine warm. Drain oil. put on a new filter, add 3qrts Automatic Trans Fluid, 1qrt of any thicker oil. Idle the engine for 30 min or so.. maybe longer. DO NOT DRIVE IT... Drain it.. If your seriously paranoid about ANY of the ATF being left behind in the oil pan. after it has drained.. dump an qrt of new oil in with the drain plug out.. should flush the pan clean of ATF. refill with your choice of oil, also a new filter. I have had great success with this method.. if you look up the properties of ATF it is fine for just idling.. but has great cleaning and detergent properties.

Darn just what I needed.. this dude is awemsome!! I'm doing this this weekend!! , mine taps or knocks but goes away after 15 seconds in the morning

you sure have a lot of faith in that red straw attached to that carb cleaner spraying down that tiny hole lol Damn thing would have fallen off if that was me.

I recommend riselone every oil change on an older engine works very well at getting rid of lifter tick. Or you can use ATF and change at shorter intervals and that helps too.

If it shows low oil pressure. Put the vehicle nose down a hill and if it’s quieter then pull the oil pan and replace the oil pickup O-Ring. It’s very common I replace a few every week.

thats freakin awesome! we texans love bm1! ive learned so much from his videos too.....love all the tool reviews and time saving tips!

I have a 2004 Chevy Trailblazer 5.3L V-8 Vortec. I use synthetic 5W30 Mobil or Pennzoil full synthetic. This is due to the engines design having tighter clearances for oil to move around. Every other oil change I use Marvel Mystery Oil in place of one quart. Keeps things clean and well lubed. I also add 6oz to a full tank to keep my fuel system working well. 10 years 172972 miles ZERO ISSUES.

I want to thank you for all your videos, I am going to try this on my tahoe since I have the same problem. BTW, you saved my volvo xc90 twice! Thanks Brian!!

This is probably the best video I've found by far... My 08 5.3 ticks so hard. I'm determined to tackle it this weekend and see if what you did will work for mine also. Thank you

i went thru on my 06 silverado (5.3L) and threw some cleaner thru all my pushrods, then buttoned everything up and did the engine flush. it still ticks a tad...but i'm sure most of what i'm hearing now is just from my longtube headers. runs like a champ though and she's significantly more quiet at idle. thanks for the thorough video man...lots of help!

Dude your a bad ass! You know your stuff. My 2000 silverado is doing the same thing. Could I try just putting sea foam in the oil right before I change it and possibly clear it out?

got 350k plus out of GM 5.3 .. They have known oil pick up tube o ring issue causing air bubble s in oil stream. After 2006 there is a small oil screen under oil pressure sender which supplies lifers . Clean it with brake cleaner. GM wants 5W30 oil only use it.

I tried this today and it fixed it. When i did my oil flush, after using carb cleaner, a lot of gunk came out. Engines runs better and no noise.

i love my sea foam i bought a 4.6 f150 and it would hold 55 psi oil pressure 10 minute later it would start smoking and drop to about 10 psi. i pulled the pvc valve and oil ran out. dip stick was empty. the pvc was clocked with wax i stopped got oil and sea foam got i checked the oil and it was full again. i put a can in the tank and 7 oz. in the engine. by the time i got home oil was 65 psi no smoke no rattle. 10 years later i'm still driving that truck and it took 3 oil changes before the oil got to looking good. and the engine is spotless on the inside now.

Great video. I dont have that truck or that problem but came across the video and liked the way you presented everything and all the tips. I'm sure it will come handy in future. Good job!!

and AGAIN, I've learned some more great stuff on youtube today!! Thanks!!

Brian, Thank you for sharing this info. A lifter in my 01 Silverado 4.8 started ticking badly like inthe video. I took off the coil pack plate and the v/c but then reconnected the coils. I started the engine. The #5 intake lifter wasn't pumping up apparantly. I didn't remove the rocker but did shoot B12 down its bleed hole. I also shot compressed air into it. I let it soak for a bit and also added 1/2 qt of ATF to the oil. I also added a little bit an STP additive that claims to quiet lifters

260,000 miles on my 5.3 never had any engine trouble change the oil every 3,000 miles runs like a champ

The biggest issue is that the lifters on the front of this motor, especially the 2nd gen version, get starved of oil and seize up on the front cylinders because of poor oiling methods. GM knew this, and replaced a bunch of these with better oil pumps or higher pressure pumps when they would fail within the 36000 mile warranty. If you have oil pressure under 30lb at idle, your front lifters are not getting enough oil to fill up, and you will hear knocking, which eventually leads to seized lifters.

Remove your cylinder heads and replace your lifters with new ones you've soaked in oil.

Ok at 70k on my 2007 new body style 4.8 Silverado, I developed a tick just like the one heard here. I also had an intermittent stabil-track warning and it would hard shift into second, it also put out a P0302 code. I changed the oil pump O-ring ( you have to remove the pan) not a bad job, couple of hours with ramps. Anyway the noise went away for about 50k miles, the truck shifted fine and the stabilitrac warning went away. So now at 170k the tick came back, it would come and go but then finally came back to a point where it was ticking at idle and got worse as Rpm increased. I finally took it to a shop I use for my classic car that does lots of engine work. Upon hearing they said they have done three lifters in the last week. They opened it up and found the number two exhaust valve cam lobe to be completely wiped out. It was rounded out. The lifter had jammed in the bore, then ground down the cam. In talking to the shop they are Retired GM service managers and mechanics that started their own shop, said that GM has had three versions of this cam, due to the lack of oil getting to the number two cylinder lifters. The newest version has a groove in it for oiling that lifter area. When I asked the manager why the noise went away when I did the procedure described in this video, he explained that if caught early you can clean the lifter but it's a limited time fix until it gunks up again due to the improper oiling of the cam and engine design. Keep in mind this does involve removing at least one cylinder head. Basic prices just a lifter change on the one cylinder if cam is still ok, 1200.00 1300.00 if you change all lifters on that side, they are in there anyway. If the cam is bad, so your talking off both heads water pump radiator looking at 2700 to 3200.00 depending on the shop cost. That said a new motor is 6700.00 installed so weigh it out.

Just did this on my 4.8 got real loud when I started it after the b12 and engine flush and bam was dead silent after a few seconds the tick is still their but very faint can’t even here it while driveing anymore. Great video helped me

Good job. I have 2008 5.3 im about to tackle. Christian Brothers Auto quoted me $3000 to $4500. I was told basically that me engines trashed evern though my oil psi is normal and no loss of power.

Exact thing just happened to my 08 5.3. Sounds very identical. Gonna pull the left side valve cover and possibly head asap. Hopefully this solves it.

The clacking did not go away immediately but it did go away the next day. It now only happens upon start up after the truck has sat a day. And even then, only briefly and not as loudly. It goes away completely after a few seconds. I use Valvoline 5w30 and NAPA filters every 6K miles. Thanx man. I owe you a steak dinner next time you are in SoCal.

super detailed so it was very helpful. no more noise. so thanks so much for the video. my question is how much would this be for a mechanic to do it at a shop.

Brian, Great video. Love the humor.

That ticking noise is from the metal on the lifters roller starting to get pitted. No solution will make it go away until you replace the worn parts. Left untreated it will eventually flatten the camshaft lobe and cause a misfire.

Thank you. It encouraged my to do my 2000 Tahoe, did both sides. Noise was still there, ended up that one bolt was loose on the flexplate. I watched some of you videos. Really good, thank you

This actually worked, i didn't unstick until i started driving. But it was a long shot that paid off. Thanks buddy!!

Bad Flux capacitor

It's not the lifters. It's the oil pump O ring leaking air into the oil lines. Oil foam goes to the hydrolic lifters. The air compress in liftee and you get a tick sound. Higher rpm the oil pressure is greater than 40 psi the tick goes away and comes back when at idle.

No Flush is a Fix!!! Only way is ( Engine Rebuild with Redesigned Pistons ). Different Oil deflector in oil pan.

thanks you for the video. funny reading all this. My 05 is doing a funny thing. 20 lbs when started. 40 when warms up, but lifter tapping when oil pressure goes from 40 lbs to 44 lbs then it stops. LOL its driving me crazy. I used this video to replace the pcv valve cover and cleaned the rods and lifter tops with the B12, but still taps. About to replace the oil pump and o-ring. 220k miles. I keep yall posted if it fixes it.

mine has lifter noise HOWEVER it goes away when the engine warms up after a cold start --really hoping this will work

lost it when you first started spraying those lifters hahaha "HAHAH YERRRAHHH" so funny. awesome video, thanks. definitely going to do this to mine.

Gunk Valve Medic works great. My Dads 98 Cheyenne had a horrendous lifter tick. Worst I ever heard. Took care of it right away. Didn't come back.

It may. You're pretty smart! motor flush is the cleaners and conditioners that make up much of what's in transmission fluid. Trans fluid is different in that its also hydraulic fluid too. You'll find trans fluid is thicker and motor flush is super thin and < 0W

Anyone know if this 5.3L is the same in the chevy suburbans and silverados

I work on 5.3 and 6 liter gm motors all the time and we replace the oil pump because they go bad all the time. I would replace the oil pressure sending unit as well since they go bad all the time as well. The tick will go away I will guarantee you that.

@andersonrowland Spark plug knock or pre-detonation is due to using an octane rating that's too low. The fix is almost always to use the manufacturer recommended octane rating.

Thanks Brian, Enjoyed watching, but more this provided the solution for my problem my 4.0 Jeep Cherokee. Just follwed your instructions and applied to my motor. What a difference. As a professional your very quick, I'm abit slower but got the job done! I used a piece of cardboard and kept my pushrods in order along with its mated rocker. Regards, Doug

Change the oil pickup O ring i changed mine problem solved

can i bring my truck to you?

Right on.I always feel better about things when I'm able to do a thorough job. That's why I like working on my own cars so much more than on a customer one. I DO have some customers that don't even ask price till I'm done and just want it done right. I LOVE THAT TOO! I save them the most money because I can just go at it right and it won't have to be done again for a long time- plus you can combine labor times if needed and have liberty to choose where the parts come from to get the best deal.

FYI Berryman b12 chemtool has methyl ethyl ketone is actually the very best to use. You can dump a 16oz can of that in there and let it run to operating temperature. That stuff is so strong and so good. Marvel mystery oil works too but it takes a long time to clear it up. I had a 2001 S10 with a 4.3 and i started using Marvel mystery oil in it with my oil change. It cleared it up and improved my oil pressure after about 3 oil changes.

I got this problem when engine is cold, over 400k now

3000 mile oil changes are a total waste of money with modern engines and oil. ANY conventional out there can easily pass an oil analysis with 5000 miles. I've witnessed 10k on conventional in an 06 Ram 4.7L and it easily passed the oil analysis at my local CAT dealer. A typical Ford F150 oil change monitor will go 10K before it recommends changing the Motorcraft 5W-20 semi syn. Full blown Syn oils can easily go 15K. So 8000 on this oil change isn't that crazy. I'm sure the oil would still qualify as good under a lab analysis for base and additive packages. It's not the 60's.

I love how you explain things. And you answer some of the 'dumb questions' that people who are probably watching wouldn't know to ask instead of just assuming everyone knows. :)

I just came to say thanks for the video. I had no idea about lifters or what their purpose was but now I'm well informed and about to tackle the problem on my truck.

3000 to 4500 hahahah...christian brother always trying to screw everyone even down here in texas.....

Brian i work for chevy. what year was this truck? ive seen lifters fail on 2009 year

this is happening right now to my 2004 Chevy Silverado. ...so glad you posted this video.....WINNING!!!

Berryman B12 is the shit, I have been preaching this product for over 10 years, once you use it you'll never buy anything else. I personally would never have put that spray nozzle down in the head, I've had to many blow off the end, and that would suck to try and extract it. Thanks for the vid

Awesome job. I have an '02 Yukon with the 6.0L, and the lifters sound pretty loud. Would this procedure be effective if you just sprayed the B-12 through the oil port of the rocker arm with the rocker arm and pushrod in place? I'm not sure what the torque spec is on tightening those rocker arms, so the idea of having to re-establish them correctly makes me mildly nervous.

John Malkovich much?

I use Marvel Mystery Oil in my crankcase. It will prevent this crud from forming in the first place. If you add it to your oil now, it will keep the passages clean. If you put 8oz for 20 gallons of gas, it will keep your fuel pump, and injectors, etc. lubricated, as well as prevent carbon from forming on your pistons and rings. And it will help keep your cat converter clean.

It's potent. Use about 1/4 of what they recommend and it will serve you well. Excessive amounts of cleaner per gas cause white concrete-like build up in your upper cylinder.

Change oil on time and you won't have that problem

You're going through a lot of work and using a wholly and completely inappropriate product for a lifter rattle. Number one, as an aside, the reason B12 clean so well is its 85% lacquer thinner which is why you don't put it inside your engine because it will melt all of the seals. It does work great the fuel tank but it is extremely dilute. If you want to clear a lifter rattle you don't take the valve cover off the engine you add a half a quart to a full quart of Marvel Mystery Oil. It has been clearing lifter rattles since they invented hydraulic lifters. Huge Advantage with Marvel Mystery Oil you can actually drive the engine with it in the oil. The reason you can do this is because Marvel Mystery Oil is motor oil. It was originally designed for World War 1 aircraft engines and not long after World War 1 it was bottled as Marvel Mystery Oil. Before you put a wrench on an engine... Try it first. Recently I had a man come up with a lifter rattle in a Land Rover. We put half a quart into the engine and it stopped before we could close the Hood. It cleans the internals of the engine better than anything else I have seen and has that huge advantage of being able to add it to the oil and drive it that way. You cannot do that with motor flush because you will damage the engine if you leave motor flush in longer than 10 to 20 minutes, most especially if you put the engine under load with it in it. You may get lucky but you also might lose a bearing or two. If you put the Marvel Mystery Oil in the engine and you still have the noise, you most likely have a mechanical issue not an oil flow issue. But in over 50 years I have only seen less than 5 occurrences of a lifter clatter be caused by anything other than an oil flow issue. The 5.3 also has an unusual issue with the oil pickup tube o-ring hardening and allowing air to flow past it which lowers your oil pressure and oil flow volume which can raise temperature of the oil and cause it to Coke up and plug the lifters. B12 chemtool, being what it consists of, has go business inside the crankcase of an engine or inside a transmission. I have only ever seen one person put a half a bottle of chemtool in there crankcase it melted the seals. And I've also heard of it happening to a transmission or two. B12 chemtool only goes in the fuel tank where is used from the spray can.

I have a 5.3L Vortec on my 04 Chevy Trailblazer. What I do is bring the engine to operating temperature. Then I check to make sure that the oil is to level. Then I pour Marvel Mystery oil run for about 4 minutes. Drain crankcase ..... because I am using synthetic oil, I add one quart of Lucas oil treatment and the remainder of quality brand synthetic oil. I have been doing this on my Trailblazer Ext LS and it runs great. I drop my oil every 4000 miles.

dump an bottle of mistry oil and run it for an week or so .. it will work for sure.. i did that few times it have always work for me

Have you ever had a motor fail after running a harsh flush like the gunk through it? You are bold if you ran it through a 180k mile engine :P

Each their own, but there's no need for any of this disassembly and expensive chemicals. Just add half a quart of ATF or Marvel Mystery Oil to the crankcase and drive the piss out of it for a few days and change the oil. A few "glugs" of Marvel oil in the crankcase every once in a while will keep this from even happening in the first place.

Ok everyone. I'm going to help a little here. I see a lot of people wondering whether they have a rod kncok or piston slap or a valvetrain noise. Easy way to tell whether it's top end or bottom. Time it. In this case there are around 5 ticks per second, or 300 per minute. The engine is turning around 600 rpms at idle. The valves of course operate once every two revolutions, so the tick occurs at half the engine speed. A crankshaft issue or piston slap would tap twice as fast.

If you've been skimping on oil changes and sludge accumulation is making your lifters stick this can help. If your lifters are simply worn out and or broken it won't help.