Draker Posted October 19, 2015 Author Report Share Posted October 19, 2015 Chain setup looks good, but that means it wasn't your noise. No broken guides or bolts? Was the crank bolt loose? Is there any back and forth slop in the crank pulley? If no to all of the above, I would replace your oil pump drive gear and spindle, and maybe even the oil pump, to be sure the noise is gone. One more thing...is there any visible wear on the inside of the timing cover? In other words, has anything been rubbing up against it? I'll pull the straight guide and inspect it. It looked fine though. Crank bolt was tight, and pulley is snug and no slop. I've got a ka pump I can put on it. The drive gear looks good but if I can find a spare I'll use it. I will put a bit more time in inspecting everything before buttoning it back up. More to come.. 1 Quote Link to comment
Draker Posted October 19, 2015 Author Report Share Posted October 19, 2015 Inside the timing cover is clean.. no anomalies. Quote Link to comment
KoHeartsGPA Posted October 19, 2015 Report Share Posted October 19, 2015 So the mystery noise unsolved thus far :( Quote Link to comment
Draker Posted October 19, 2015 Author Report Share Posted October 19, 2015 I've started to build a rockauto shopping list. Holding off on ordering until I get a bit more time to poke around. 1 Quote Link to comment
banzai510(hainz) Posted October 19, 2015 Report Share Posted October 19, 2015 ck the distributor also/ Take out and spin it. I had one with the weights exploded jamming it up. then this weekend my 521 felt like it was running out of gas. I said FUCK. so i changed the fuel filter and nothing I said OK its the distributor. Not the carb. I swapped in another distributor with a Pertreonix and the truck was like I put a bigger cam in there. Looked at the old dist and the vaccuum advance seem locked up. Thats all it was so nice to have spare parts ready to go and swap in. I did the dist first as it was a 1 bolt operation. 1 Quote Link to comment
shacks510 Posted October 21, 2015 Report Share Posted October 21, 2015 The sleeve inside the timing cover where the oil pump shaft passes through could be worn excessively. It's more likely to be worn than the steel shaft. Put the shaft through the hole as it would be installed and make sure there isn't excessive play. Cover will need to be replaced if play is excessive. Quote Link to comment
Draker Posted October 21, 2015 Author Report Share Posted October 21, 2015 The sleeve inside the timing cover where the oil pump shaft passes through could be worn excessively. It's more likely to be worn than the steel shaft. Put the shaft through the hole as it would be installed and make sure there isn't excessive play. Cover will need to be replaced if play is excessive. I'll check it out. Anything is possible.. Quote Link to comment
Draker Posted October 25, 2015 Author Report Share Posted October 25, 2015 I'll pull the straight guide and inspect it. It looked fine though. Crank bolt was tight, and pulley is snug and no slop. I've got a ka pump I can put on it. The drive gear looks good but if I can find a spare I'll use it. I will put a bit more time in inspecting everything before buttoning it back up. More to come.. The straight chain guide looks good. I'll swap pumps and spindles when it goes back together with spares I have. ck the distributor also/ Take out and spin it. I had one with the weights exploded jamming it up. then this weekend my 521 felt like it was running out of gas. I said FUCK. so i changed the fuel filter and nothing I said OK its the distributor. Not the carb. I swapped in another distributor with a Pertreonix and the truck was like I put a bigger cam in there. Looked at the old dist and the vaccuum advance seem locked up. Thats all it was so nice to have spare parts ready to go and swap in. I did the dist first as it was a 1 bolt operation. No slop in the dizzy, spins smooth, no binding.. all clear. The sleeve inside the timing cover where the oil pump shaft passes through could be worn excessively. It's more likely to be worn than the steel shaft. Put the shaft through the hole as it would be installed and make sure there isn't excessive play. Cover will need to be replaced if play is excessive. Just checked this and the clearance seems just fine. No slop. Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 Bad news.. Noise isn't really by the oiler.. I mean I can hear it there.. but new theory is a wrist pin. Either way.. not great news. I did drive it around the block a few times today.. that was fun. But this motor is coming out. Looking for a short block.. there is an event next weekend.. so I've got 7 days to get this back on the road. And before any of you suggest it's a bearing, I assure you. It's not. Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 Inspected it all when it was out the last time. I didn't really check the pistons though.. I was focused on the timing components. Quote Link to comment
datzenmike Posted April 11, 2016 Report Share Posted April 11, 2016 Are you running a synthetic oil? If so, swap in some 15 w 40. Won't be the main bearings they just turn in a non moving block. A rod would be more likely but I doubt it. Tighten your lifters. Take them way down temporarily and see how it sounds. 1 Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 Are you running a synthetic oil? If so, swap in some 15 w 40. Won't be the main bearings they just turn in a non moving block. A rod would be more likely but I doubt it. Tighten your lifters. Take them way down temporarily and see how it sounds. delo 15-40. I adjusted the lifters with the head off. Then I double checked them when they were hot, yesterday. I agree about the bearings. Those were just the ones I took pictures of. 1 Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 I busted out the stethoscope again tonight. The sound was the loudest between the oilpan and trany. Right at the back of the oil pan. It definitely seemed to be coming from below. Again, sound goes away when you rev it up. Bizarre! Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 Also, I should mention, I mic'd all crank journals and bearing surfaces when I rebuilt the motor. Everything looked good. I also plastigauged it for good measure. Bearings were fine. I don't recall any play in the wrist pins either.. but perhaps when they get warm... 1 Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 It's still warm... Quote Link to comment
KoHeartsGPA Posted April 11, 2016 Report Share Posted April 11, 2016 Damn dude... Quote Link to comment
datzenmike Posted April 11, 2016 Report Share Posted April 11, 2016 I don't recall any play in the wrist pins either.. but perhaps when they get warm... The wrist pins are press in fit on the rods and loose fit on the pistons. As the pistons are hyper eutectic they swell from the heat very little. The pins are steel and will swell ... so the clearance will get tighter not larger. Forgot to ask, does it make this small noise when the engine is cold? Quote Link to comment
banzai510(hainz) Posted April 11, 2016 Report Share Posted April 11, 2016 I have a early valve cover and I notice w/o the gasket it would hit the cam tower. I assume with the gasket it might work but torq down it will be a close fit. maybe the vabration is going thru that. Its a Hail Mary on this but just to let you know. bearings look fine. I wont use syn oil myself 1 Quote Link to comment
datzenmike Posted April 11, 2016 Report Share Posted April 11, 2016 At $8-$12 a liter fuck that. As I said before it does sound a lot like every L20B to me. 1 Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 The wrist pins are press in fit on the rods and loose fit on the pistons. As the pistons are hyper eutectic they swell from the heat very little. The pins are steel and will swell ... so the clearance will get tighter not larger. Forgot to ask, does it make this small noise when the engine is cold? It does make the sound cold, but much louder when hot. Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 I have a early valve cover and I notice w/o the gasket it would hit the cam tower. I assume with the gasket it might work but torq down it will be a close fit. maybe the vabration is going thru that. Its a Hail Mary on this but just to let you know. bearings look fine. I wont use syn oil myself It made the noise with both covers. At $8-$12 a liter fuck that. As I said before it does sound a lot like every L20B to me. It's pretty pronounced. Not normal. I'm sure there are a lot of worn out motors that sound like this.. lol Quote Link to comment
KoHeartsGPA Posted April 11, 2016 Report Share Posted April 11, 2016 This is a bizarre case as all the moving parts from that engine have been checked thoroughly....any chance it could be the starter maybe the pinion gear isn't retracting fully?....long shot I know....but.... Quote Link to comment
Draker Posted April 11, 2016 Author Report Share Posted April 11, 2016 This is a bizarre case as all the moving parts from that engine have been checked thoroughly....any chance it could be the starter maybe the pinion gear isn't retracting fully?....long shot I know....but.... Naw, not the starter. It was used on my L16. No issues there. Quote Link to comment
Draker Posted October 3, 2017 Author Report Share Posted October 3, 2017 So we might have an update to this mystery. I didn't scrap the motor because I wanted to know what the issue was. I was going to hold on to it until I needed to rebuilt it. My buddy Dennis was looking for a L20 to rebuild so I sold it to him and explained it needed a rebuild to a mystery noise. I showed him the videos. He took it to the machinist to inspect and ultimately build. His thoughts regarding the noise: He thought there might have been slop in the chain due to the wear in the oiler. But it was worn before, you can see it in the pictures I posted. His other theory is that there was RTV under the rear main cap. The FSM states to put RTV back there, just a bit. I may have put too much. The theory is that the RTV may have caused excessive clearance. Hard to say because it's been so long, but I plasti-gauged everything and measured all clearances with a mic. It's weird because the noise was in the chain area, then it got worse.. Anyway, sounds like it's getting new pistons, work on the crank, decking the block.. etc. Will be back up and running again soon! Just not in my car... lol Quote Link to comment
datzenmike Posted October 4, 2017 Report Share Posted October 4, 2017 Not RTV. Is nowhere near the bearing cap. A couple of dabs where the oil pan gasket meets the cap Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.