The_Magicians_Eye Posted January 15, 2012 Share Posted January 15, 2012 I vote for lifters and or heavy wear on your rocker shafts. Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 15, 2012 Author Share Posted January 15, 2012 I have definitely thought about that but it sounds VERY metalic. you must have something completely different from me. Make a video. When you say "very metallic" that makes me think of banging a metal pipe on another metal pipe or something. I wouldn't classify mine as metallic at all really. If you can hear it at regular driving speed, that either means that it's going much slower than my noise, or you have the best hearing in the world. Link to comment Share on other sites More sharing options...
silver97ex Posted January 15, 2012 Share Posted January 15, 2012 I will try to make a video when I get a chance, it is 15 degrees outside right now... Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 16, 2012 Author Share Posted January 16, 2012 I will try to make a video when I get a chance, it is 15 degrees outside right now... man up! girl scout Link to comment Share on other sites More sharing options...
silver97ex Posted January 16, 2012 Share Posted January 16, 2012 No need to man up when I could/did wait till today when it is 38 degrees... Link to comment Share on other sites More sharing options...
silver97ex Posted January 16, 2012 Share Posted January 16, 2012 (edited) http://www.youtube.com/watch?v=p-Q3hFVpG3U http://www.youtube.com/watch?v=wJDblkajNN8 http://www.youtube.com/watch?v=5-0cAZnV9PM Edited January 16, 2012 by silver97ex Link to comment Share on other sites More sharing options...
silver97ex Posted January 17, 2012 Share Posted January 17, 2012 No replies to the videos?? Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 17, 2012 Author Share Posted January 17, 2012 No replies to the videos?? I could have sworn I replied to this last night. Must have dreamed it. Anyways, pretty much what I typed, or thought I typed was that yours DOES sound a bit like mine. It might be the exhaust, but I can't hear it at all engine ranges like you can. You were totally right about that. I think I hear a minor idler pulley squeak. Link to comment Share on other sites More sharing options...
JamesRich Posted January 18, 2012 Share Posted January 18, 2012 No replies to the videos?? That sounds pretty bad! The way it quiets down when you rev it suggest a lifter that is just totally collapsing at idle. It's loud enough to be a rod knock too. Do you hear it more on top or under the truck? If on top more on the passenger side or driver side? If you hear it more under the truck I would say it's a rod knock but a rod knock will get louder under load. If it's on top I'd go with a lifter but if it's collapsing that bad it could damage your cam if it hasn't already. James Link to comment Share on other sites More sharing options...
silver97ex Posted January 18, 2012 Share Posted January 18, 2012 Sorry for the long post ahead of time.... It definitely sounds like it is coming from the top. It definitely sounded like it was coming from the driver's side so I replaced the driver's side lifters (brand new from Nissan dealership) and the sound didn't change at all. None of the old lifters that I took out were collapsed or even compressable by hand. It doesn't really go away when you rev it, just harder to hear over the engine. Like I mentioned before, the only time it actually goes away is during engine braking. The only thing I can think that changes during engine braking vs idle or accelerating is vacuum increases. Engine has 232,xxx miles, new OEM driver's side lifters, new pcv valve, doens't burn or leak a drop of oil. I am at a loss at this point. I guess it wouldn't be too dificult to check the passenger side lifters. It sounds like either driver's side or middle of engine. I guess its time to get the stethescope out again. If I remember correctly, with the stethescope it was more pronounced on the drivers side VC, head, and exhaust mani. Very hard to exactly pinpoint it again. Link to comment Share on other sites More sharing options...
Kingman Posted January 18, 2012 Share Posted January 18, 2012 (edited) Lifter(s) collapsing at idle or excessive wear in the rocker arm shafts allowing the rocker arms to twist. Pop the valve covers off and turn the engine over as each valve closes, then wiggle the rocker arms. If there's a lot of play side to side then that's probably your issue. Here's a video of what I'm talking about. The furthest right rocker arm has WAY too much play in it, the middle is okay but getting there. Both valves are closed. This is on a 115K mile engine. http://www.youtube.com/watch?v=jVdb_7fn-aI&feature=youtu.be Edited January 18, 2012 by Kingman Link to comment Share on other sites More sharing options...
silver97ex Posted January 18, 2012 Share Posted January 18, 2012 Then that would be a matter of replacing the rocker arm shafts? Those come with the rocker arms on them? Just the noise of you wiggling them sounds a lot like my noise, just less extreme. I guess I know what I am doing soon... Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 18, 2012 Author Share Posted January 18, 2012 Lifter(s) collapsing at idle or excessive wear in the rocker arm shafts allowing the rocker arms to twist. Pop the valve covers off and turn the engine over as each valve closes, then wiggle the rocker arms. If there's a lot of play side to side then that's probably your issue. Here's a video of what I'm talking about. The furthest right rocker arm has WAY too much play in it, the middle is okay but getting there. Both valves are closed. This is on a 115K mile engine. http://www.youtube.com/watch?v=jVdb_7fn-aI&feature=youtu.be thanks for the video. How does that happen? lack of oil from low quality oil and filter? Link to comment Share on other sites More sharing options...
adamzan Posted January 18, 2012 Share Posted January 18, 2012 Someone probably ran it low on oil at some point in it's life. Link to comment Share on other sites More sharing options...
nismothunder Posted January 18, 2012 Share Posted January 18, 2012 Misalighment during installation I believe. It probly puffed a little smoke when it started. Link to comment Share on other sites More sharing options...
silver97ex Posted January 18, 2012 Share Posted January 18, 2012 I would assume it is recommended to replace the rockers that are on that shaft as well, not just the shaft. Link to comment Share on other sites More sharing options...
Kingman Posted January 18, 2012 Share Posted January 18, 2012 Shaft and rocker arms, yes. Link to comment Share on other sites More sharing options...
sewebster Posted January 19, 2012 Share Posted January 19, 2012 Misalighment during installation I believe. It probly puffed a little smoke when it started. I don't think you can misalign them during installation really. If you don't have them in the right place you can't tighten the rocker shaft down (at least not in any reasonable way!) Link to comment Share on other sites More sharing options...
nunya Posted January 19, 2012 Share Posted January 19, 2012 I don't think you can misalign them during installation really. If you don't have them in the right place you can't tighten the rocker shaft down (at least not in any reasonable way!) Never underestimate the power of people who think their mechanics! Link to comment Share on other sites More sharing options...
sewebster Posted January 19, 2012 Share Posted January 19, 2012 Never underestimate the power of people who think their mechanics! Heh, I guess I should admit that I forgot to torque a rocker shaft down once... that led to some loud tapping, let me tell you Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 19, 2012 Author Share Posted January 19, 2012 Something just came to mind. If there's play in the rocker arms and the shafts, then why doesn't it get worse? I assume that the tapping is due to the metal hitting metal. Over time, wouldn't shavings accumulate and create more play? That noise sounds really close to mind, but it hasn't gotten any worse over 5000 miles. Link to comment Share on other sites More sharing options...
Slartibartfast Posted January 19, 2012 Share Posted January 19, 2012 Assuming Adamzan's right, and it was run without enough oil at some point, that's probably when the wear happened. Now that it's properly oiled, it'll take a while to get worse. Keep in mind, oil circulates, so whatever wears off gets caught (hopefully) in your oil filter. And I don't know rockers, but that's a lot of play. Link to comment Share on other sites More sharing options...
silver97ex Posted January 29, 2012 Share Posted January 29, 2012 Ok, so I changed my driver's side rocker arms and rocker arm shafts. My noise did get better but it is not gone. Before I replaced them 4 of the 6 moved side to side. With the brand new OEM rockers and shafts, one still had play in it. My noise is better, but it is NOT gone. I am getting a bit frustrated and weighing my options right now... Link to comment Share on other sites More sharing options...
1994SEV6 Posted January 29, 2012 Author Share Posted January 29, 2012 With the brand new OEM rockers and shafts, one still had play in it. a BRAND NEW rocker and shaft set still had play in it? whatttt? How much did the parts cost you by the way? I have to eliminate other possibilities first (water pump, pulleys, etc), but I think I will have to end up replacing on my engine what you had to replace. Link to comment Share on other sites More sharing options...
sewebster Posted January 29, 2012 Share Posted January 29, 2012 Ok, so I changed my driver's side rocker arms and rocker arm shafts. My noise did get better but it is not gone. Before I replaced them 4 of the 6 moved side to side. With the brand new OEM rockers and shafts, one still had play in it. My noise is better, but it is NOT gone. I am getting a bit frustrated and weighing my options right now... I replaced my rocker shafts and arms recently and there is still some "play" in the arms... but I'm not convinced it's actually a problem. If you just mean they can shift side to side, then I think that is just a function of the design of the system. That said, I do seem to have some sort of tick I haven't really been able to figure out (I still think it might be exhaust related) so who knows... You can measure the shafts and rocker bores to see if they are within spec (see FSM). 1 Link to comment Share on other sites More sharing options...
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