caseyctsv Posted February 27, 2017 Report Share Posted February 27, 2017 You know how many people don't listen to me, and I'm a GM certified tech? This is why I don't even bother much anymore, besides trying to be nice typically turns into getting taken advantage of. You and Doc are but a few who never tried to abuse my kindness, you'll never know how much I appreciate that. It sucks that people take advantage of this stuff. I have always respected your knowldge on the LS platform though I assume it stretches much further than that. I still think there has to be a better way for you to utilize your knowledgE but we are drifting on this thread Quote Link to comment Share on other sites More sharing options...
russian rocket Posted February 27, 2017 Author Report Share Posted February 27, 2017 Those motor mounts are joyous to do at home. seems like it, i have been doing some research and gm recommends dropping the diff....fuck that lol. when i pull the exhaust manifold to extract the broken bolts i think ill have enough room to slide it out with out to much struggle Quote Link to comment Share on other sites More sharing options...
cdk 4219 Posted February 28, 2017 Report Share Posted February 28, 2017 it is a pain without a lift. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted March 25, 2017 Author Report Share Posted March 25, 2017 just a little update, i fixed the broken exhaust studs, replaced the gasket, replaced the broken motor mount and took care of a couple other things while i was at it. unfortunately the noise has come back and it seems louder now than before and even goes up and down with the rpms. im kinda starting to think it might be a spun rod bearing. i did do some reading and some other people have reported a noise when their vvt actuator started to go bad. so i think that might be the next step, tear the front of the engine apart, drop the oil pan, replace pump, chain and vvt actuator and see what it does. if that doesnt fix it, there are really only two things left, lifter going bad or rod knock. ill try to check the rods when i have the pan off but i am not sure if there is a windage tray or not. just watched a video on youtube and maybe possible it could be a dropped valve seat? Quote Link to comment Share on other sites More sharing options...
russian rocket Posted March 25, 2017 Author Report Share Posted March 25, 2017 here is a video of the noise Quote Link to comment Share on other sites More sharing options...
russian rocket Posted March 25, 2017 Author Report Share Posted March 25, 2017 (edited) alright guys, an update to my update. so prior to the noise showing up today, i had my wife hold the rpms at 2500 for a couple minutes so that i can try to track down a squeaking noise that only happens off idle, the knocking started after a couple minutes of idling at 2500. so i let the car cool off about 20 minutes or so and went out and started it again, noise was there immediately. so i shut it off and added a quart of oil, mind you it was 1/3rd above the fill line already. so i started it up and the noise started to subside and completely went away. the oil pressure has always been good and has not shown any signs of going down. so i went ahead and held the rpms steady at 2500 for a couple minutes, the noise finally reappeared. i let off the throttle and let it idle for a couple minutes as i walked around the car, the noise started to subside again and finally completely went away. sooo, i wouldnt think the oil pump relief valve would be giving me any issues because the oil pressure always stays good, even when the noise is evident. i am starting to really lean towards the vvt actuator but i dont know under what conditions its supposed to activate, anyone have a clue? Edited March 25, 2017 by russian rocket Quote Link to comment Share on other sites More sharing options...
caseyctsv Posted March 26, 2017 Report Share Posted March 26, 2017 The lifters are known to fail on the AFM motors for what it's worth. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted March 26, 2017 Author Report Share Posted March 26, 2017 The lifters are known to fail on the AFM motors for what it's worth. fortunately this is a non afm engine. read a couple more things about oil pick up tube o rings going bad, i guess ill find out when i drop the pan. Quote Link to comment Share on other sites More sharing options...
caseyctsv Posted March 26, 2017 Report Share Posted March 26, 2017 fortunately this is a non afm engine. read a couple more things about oil pick up tube o rings going bad, i guess ill find out when i drop the pan. Good luck man. My best friend is dealing with a similar issue on his 2005 Suburban - he is also tracking it down. I will Let you know if we figure his out. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted March 26, 2017 Author Report Share Posted March 26, 2017 Good luck man. My best friend is dealing with a similar issue on his 2005 Suburban - he is also tracking it down. I will Let you know if we figure his out. thank you, i appreciate it. Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted March 26, 2017 Report Share Posted March 26, 2017 seems like it, i have been doing some research and gm recommends dropping the diff....fuck that lol. when i pull the exhaust manifold to extract the broken bolts i think ill have enough room to slide it out with out to much struggle Don't let the diff discoruage you. You can have it out in 5-10 minutes. Front driveshaft bolts, 4 mount bolts, 6 axle bolts on each side, unhook electrical connector and vent hose. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted March 26, 2017 Author Report Share Posted March 26, 2017 Don't let the diff discoruage you. You can have it out in 5-10 minutes. Front driveshaft bolts, 4 mount bolts, 6 axle bolts on each side, unhook electrical connector and vent hose. i ended up replacing the mount with the diff and exhaust manifold still in place, it wasnt too bad. a bit tight but overall not that bad. i did remove the inner fender cover which helped out a lot. i worked the crap out of that motor mount heat shield, glad its so pliable lol. once i had all the bolts out, i was able to turn the mount enough so that i could access the nuts on the back that hold the heat shield and mount bracket. then i took it out in 3 pieces. so far the hardest part of this whole thing has been removing the manifold to cat nuts, those were a mother fucker. only one of them came off willingly, the other two completely stripped out and one of those two had welded itself to the stud, an irwin nut extractor didnt even work. i managed to get my angle grinder in there to cut the nut off, i cut that damn thing in 2 places completely through to the stud and it still wouldnt budge. Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted March 27, 2017 Report Share Posted March 27, 2017 i ended up replacing the mount with the diff and exhaust manifold still in place, it wasnt too bad. a bit tight but overall not that bad. i did remove the inner fender cover which helped out a lot. i worked the crap out of that motor mount heat shield, glad its so pliable lol. once i had all the bolts out, i was able to turn the mount enough so that i could access the nuts on the back that hold the heat shield and mount bracket. then i took it out in 3 pieces. so far the hardest part of this whole thing has been removing the manifold to cat nuts, those were a mother fucker. only one of them came off willingly, the other two completely stripped out and one of those two had welded itself to the stud, an irwin nut extractor didnt even work. i managed to get my angle grinder in there to cut the nut off, i cut that damn thing in 2 places completely through to the stud and it still wouldnt budge. That's pretty common. I just had to put a cam in a 2013 yukon. Had to heat the downpipe nuts red hot to get them loose. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted April 5, 2017 Author Report Share Posted April 5, 2017 got some work done on it today. replaced the oil pump, timing chain, tensioner, vvt solenoid and dropped the pan. Im going to replace the rod bearings while im at it. stock ones with 180k miles on them dont look bad at all Quote Link to comment Share on other sites More sharing options...
russian rocket Posted April 6, 2017 Author Report Share Posted April 6, 2017 well its back together for the most part, still have to put the front diff back in. I went ahead and primed the engine and fired it up, its quieter now on cold start than its ever been. Everything sounds good and it idles smoothly, BUT...i dont know if this is a good thing or a bad thing yet, the oil pressure is pretty damn high. It sits and idles at around 60psi and naturally increases as the rpms increase. i have not let it come up to full operating temp yet, but this is a HUGE difference from how it used to be. it used to go up to 40-50psi on cold start and with in a couple minutes it would drop below 20psi. now it stays steady at 60psi. i am kicking myself in the ass just a little because i did not plastigauge the new rod bearings, i did however mic one out and the size came back identical to what i removed. Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted April 6, 2017 Report Share Posted April 6, 2017 well its back together for the most part, still have to put the front diff back in. I went ahead and primed the engine and fired it up, its quieter now on cold start than its ever been. Everything sounds good and it idles smoothly, BUT...i dont know if this is a good thing or a bad thing yet, the oil pressure is pretty damn high. It sits and idles at around 60psi and naturally increases as the rpms increase. i have not let it come up to full operating temp yet, but this is a HUGE difference from how it used to be. it used to go up to 40-50psi on cold start and with in a couple minutes it would drop below 20psi. now it stays steady at 60psi. i am kicking myself in the ass just a little because i did not plastigauge the new rod bearings, i did however mic one out and the size came back identical to what i removed. My G8 idles at 55-60 cold, and 45 hot. It'll go to 80-90 psi when cold above 3k rpm Did you keep or remove the oil pressure bypass in the oil pan? Quote Link to comment Share on other sites More sharing options...
russian rocket Posted April 6, 2017 Author Report Share Posted April 6, 2017 My G8 idles at 55-60 cold, and 45 hot. It'll go to 80-90 psi when cold above 3k rpm Did you keep or remove the oil pressure bypass in the oil pan? oh cool! then my numbers are spot on compared to yours, the oil pressure did end up dropping down to 42-45psi when it was full warmed up idling. I left the oil pan as it is. Quote Link to comment Share on other sites More sharing options...
xlr8tn Posted April 7, 2017 Report Share Posted April 7, 2017 that sounds valvetrain related to me....bent pushrod or collapsed lifter is my official guess. Been wrong many times before though. Just what it sounds like to me. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted April 8, 2017 Author Report Share Posted April 8, 2017 that sounds valvetrain related to me....bent pushrod or collapsed lifter is my official guess. Been wrong many times before though. Just what it sounds like to me. i would think a bent push rod would create the noise at all times, not just now and then. I have been kinda thinking a collapsed lifter too, maybe one that is on its way out, it collapses, then works itself loose and works again for sometime. from what i could tell though, all the cam lobs looked pretty good, i mean i can see the path that the lifter rids on the cam, but nothing looked gouged or scorn. the only problem with a collapsed lifter theory, i would think the car would run somewhat ruff performance wise when the lifter is collapsed. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted April 9, 2017 Author Report Share Posted April 9, 2017 well, so far so good. engine runs nice and smooth, great oil pressure. its even quiet now on cold starts, so maybe that wasnt piston slap that i was hearing after all. the noise hasnt come back yet, so lets hope its done and over with. Quote Link to comment Share on other sites More sharing options...
russian rocket Posted July 1, 2017 Author Report Share Posted July 1, 2017 as a final update, we just drove the yukon ~2500 miles to florida and back in 6 days and it ran perfectly. never once did i hear the knocking sound. so i consider this case closed. it now has 188k miles on it and still running strong Quote Link to comment Share on other sites More sharing options...
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