5.7 Liter Vortec Valvetrain noise?

Hello all here I am again asking for help because I have 99% of the Burb the way I want it, except for the irritating valvetrain noise. When I put one end of a tube on the driver's side exhaust manifold and the other to my ear, I can really hear a ticking noise. I can hear it all the way through the exhaust system until I hit the muffler, which muffles it of course. I am wondering if it is possible that the cylinder is actually physically hitting the valve? My cylinder heads have been taken off by the previous owners and "re-machined". Would a crappy machine job result in the cylinder hitting the valve? If the cylinder is indeed hitting the valve, can I adjust it somehow by taking the heads off? Can I adjust it without taking the heads off? Is it probably not the cylinder hitting the valve, but just old lifters? Or low quality lifters? Or bad valve adjustment? I adjusted the valve lash, and it did not seem to help. It really is more noticable sometimes than others but it is always there. I am ready to tear into half of my engine to fix the problem because it is not a healthy sound. I figure I could replace the lifters with a new set of lifters, but I just wanted to know if it could be more than just old lifters. Any help is very appreciated. Thank you!

I doubt if the piston is hitting the valve it would have bent by now and you would have other issues. Try and pinpoint the source is it valve train or lower end? Remove the cover and feel the rockers see if you can see if one of them is the source, or an exhaust leak at the manifold, from here noises are nearly impossible.

Thanks for the reply maxwedge. I took the valve cover off and re-adjusted the valve lash, I remember in the past one rocker arm in particular being tightened a little much in my opinion. I adjusted them to zero lash, and the 1/4 of a turn. Assembled everything and still have the noise, although it sounds different. Less terminal I suppose is a good way to describe it. But I still have a noise, and it sounds like a sewing machine. I suppose this would be lifter noise? I should have pulled out a pushrod to see if there was gunk on it or not. I have run seafoam through the crankcase a while back to no avail. I have had this noise for as long as I have owned the car. I am running royal purple 5w-30 in it, with an AC-Delco oil filter. I suppose I might just replace all the lifters when I get a chance to tear everything apart. Would a good engine cleaner be good to use? Just to see if it affects the noise? Has anyone effectively used an engine cleaner for this type of problem? If so what kind would that be? That would point me in the direction of whether its gummed up or just worn lifters, or a crappy valve job. I just bought all my oil so I guess I would like to not have to drain it all again but that's life. Thank you for the ideas, I really appreaciate it.

Oh by the way the engine makes this noise all the time, not just when it's cold or when it's warmed up. It is randomly more noticeable at times than others, but it is always there.

Ok because I am antsy I went to Autozone and picked up a bottle of Rislone. I know additives usually aren't remedies to anything, but curiosity killed the cat this time. I added about half of a bottle to the oil, then I took off to a desolate country road for a couple of good full throttle starts. I took it real easy coming home, and I pulled into the driveway and put it in park, and there was absolutely no noise! It was honestly a miracle for that few seconds before I turned the car off, drained a little oil and added more of the rislone. Well I did the same process again, but instead of being completely quiet, it comes on and off. For example: "tick tick tick tick, silence silence, tick tick tick, silence, tick tick tick tick silentick tick tick tick silence silence silence tick tick quieter tick......." etc you get the picture. Really irritating. Anyway does this mean that possibly it isn't lifter wear as much as it is sludge? It has never been as quiet as it was for that few seconds, honestly as long as I have owned it, there has never been that much silence from the valve-train, I should have just left it running like that forever :tongue:. Anyhow I appreciate any ideas or knowledge you can shed on the situation.

Interesting...

I had lifter noise in a Subaru years ago, and I was young and impressionable and thought that additives would help. I poured Engine Honey into it, and the problem disappeared entirely. I also changed to a heavier weight oil.

I ran the car for several years without issue.

Am I suggesting that you go ahead and do this? No. I wouldn't do it in my current Tahoe as I suspect there's more to it than just a buildup. Not to mention, a post in one of the forums recently pointed out that freeing up all of that gunk may cause it to collect in the oil pump and make it fail. Good internet rumor, at least, but a consideration.

Keep us posted, good luck.

I'll keep you posted. I most likely will replace the valve lifters. I am considering replacing the lifters, cam-shaft, and timing set. However this may be a little over-kill for an engine with 156,000 miles. I have a very slow intake manifold coolant seep that I should take care of, I figure if I'm going to have the intake off anyway, I might as well replace the lifters.

I'd check oil pressure first here, the additives are not the answer here, I've seen a blocked oil pump pick up cause this. I can't see all the lifters being bad, if one was bad you would feel it in a rocker arm when checking the source. You need to do further diagnosis before doing anything here. These additive can move deposits around the engine which can cause more problems.

I agree with you maxwedge, additives aren't remedies in fact they usually just mask the problem if they do anything. Oil pressure is 15psi idle after it is all warmed up, hangs around 40psi while driving. I hated to do it but I'm too curious to I tore off the valve cover again this evening. Turned the engine on and examined each rocker arm. All were rocking exactly the same like they should. Put my fingers on each one, and each lifter was lifting nice and strong in uniform. Hmmm. I decided I didn't have enough oil in my engine compartment, so while it was running, I backed up each rocker arm until it was ticking, then tightened it up to where it stopped ticking and then just a tiny pinch more. After messing around with all the lifters I got the noise to go away! I can still hear the lifters a little bit but its a Chevy 350 with a roller cam and 158,000 miles, it's a typical sound. At this point the valves on the driver side were even quieter than the passenger side. Yay! It all went well, other than me accidentally mixing up two spark plugs wires while putting it all back together. I think I will try this method of adjustment on the other side. If that works like this did, this thing will sound almost new. Anyway thanks to all, and I will let you know how the other side goes, and if I make a stupid accident like drop a bolt down an oil passage and grenade my engine.:grinno:

A much better option than additives. Thanks for the update, I'll throw this in my bag of tricks.

I did the same process on the other side and wow. It almost sounds like a new engine. I truly believe the most effective way to do this is with the engine running. I've heard about a trick where you use some old crappy valve covers and cut holes in the just big enough for the socket, that way it isn't so messy. But it wasn't too bad without the valve covers on if you are relatively quick about it. Anyhow, it sounds much better and I am glad!

Good, kinda tought that was the issue, running is the best way but much harder to do.