datzenmike Posted September 12, 2015 Report Share Posted September 12, 2015 Poo. Would have been a cheaper easier fix. Quote Link to comment
noramost Posted September 12, 2015 Report Share Posted September 12, 2015 We had a recall @ the dealer once to remove the gasket between the block and tensioner for chain noise. Most common noise is rockers not level because valve depth not set corectly. Use the blue oil filter made in Japan to keep your oil circuit primed and your chane will last 250k instead of 80k Quote Link to comment
datzenmike Posted September 12, 2015 Report Share Posted September 12, 2015 I find the L series were extremely overbuilt, which is fine. The chain is well oiled from cam spray and dribbled oil from the tensioner but Nissan also placed an oil jet right beside it between the chain above the crank sprocket. This was later deemed not needed and dropped on the Z22 and later Z20/Z24 used on the 720. Quote Link to comment
Stoffregen Motorsports Posted September 12, 2015 Report Share Posted September 12, 2015 Anybody want to start placing bets? I bet it's a bad oil pump drive and/or spindle. Quote Link to comment
datzenmike Posted September 12, 2015 Report Share Posted September 12, 2015 No updates. Taking a bit of time away from wrenching. Here is the video from before Shasta. It sounds worse than this now. Sounds like any other L series, but my ears are kind of old. Every now and then random loud tic? Do you have a recent sound clip? Do you have a stock L20B oil pump? Quote Link to comment
Draker Posted September 12, 2015 Author Report Share Posted September 12, 2015 Sounds like any other L series, but my ears are kind of old. Every now and then random loud tic? Do you have a recent sound clip? Do you have a stock L20B oil pump? I'll try to get a better clip and post it. I believe it's a stock pump. 25-3psi at idle hot. Not sure how to ID if ka or stock. Quote Link to comment
datzenmike Posted September 12, 2015 Report Share Posted September 12, 2015 25-30 is probably fine. A KA pump has longer internal pump rotors (13% longer, I measured them) and will boost hot idle pressure. MY very old L20B hot idle went from 17-28 PSI just from a pump change. (and a used S13 pump from a wrecking yard too!) The higher pressure will push the tensioner out slightly. I don't know if that's why it gets quieter in the vid. Quote Link to comment
KoHeartsGPA Posted September 12, 2015 Report Share Posted September 12, 2015 Mine is the pump Julian ran on his L20bt, hot (190℉+) is 15 to 17psi, as soon as I rev over 1400 it hits 50 to 55psi, it's a stock pump. Quote Link to comment
Draker Posted September 12, 2015 Author Report Share Posted September 12, 2015 I max around 50 also. Quote Link to comment
Draker Posted September 12, 2015 Author Report Share Posted September 12, 2015 You in town this weekend Diego? Quote Link to comment
KoHeartsGPA Posted September 12, 2015 Report Share Posted September 12, 2015 I should be home by 7:30 tonight, just left Corning Ca, gotta deliver 1pm tomorrow in Albany, I can come over when I get back if you like Quote Link to comment
Draker Posted September 12, 2015 Author Report Share Posted September 12, 2015 Yeah I'll txt you tomorrow. 1 Quote Link to comment
datzenmike Posted September 12, 2015 Report Share Posted September 12, 2015 Yes... all sizes are limited to close to the same max pressure. The larger KA pumps will run higher pressure at idle and reach max sooner than the small ones. 1 Quote Link to comment
Carter 71 Posted September 13, 2015 Report Share Posted September 13, 2015 I had the same problem with my rebuilt L20B, at first I thought it may be the tensioner- I did put in a new one on the rebuild but maybe a bad part. On some internet digging it turns out all L series engines will get slack in the timing chain if the head or block has been skimmed, and the easiest way to fix this is to install shims under the cam towers. Did yours get skimmed, or has it been skimmed in the past? By wondrous Japanese design, the cam towers share the same bolt pattern and shape across the L range, and fortunately a Nissan/Datsun Z specialist down in Essex had a set on the shelf. They were in my hand the next morning. Installed them.... Rockers removed, Cam out, taking huge care that the timing chain didn't come off etc (zip-tied the chain) Shim installed, one at a time Totally sorted the problem. Running super sweet! Quote Link to comment
Carter 71 Posted September 13, 2015 Report Share Posted September 13, 2015 Just to add, didn't have to pull the engine out. Also, obviously had to reset the valve clearance too. Quote Link to comment
datzenmike Posted September 13, 2015 Report Share Posted September 13, 2015 This reminds me, speaking of gaskets. Every oil pump gasket I have seen is paper thin. I mean paper thin. If a home made or thicker one was installed the spindle might ride slightly lower. Have a look when you pull it off. Quote Link to comment
banzai510(hainz) Posted September 13, 2015 Report Share Posted September 13, 2015 I don't think 1 tower shim(.015 most) is going to cause this noise. Just my opinion 1 Quote Link to comment
Draker Posted September 13, 2015 Author Report Share Posted September 13, 2015 I didn't do any machine work. Head may have been surfaced by PO at some point possibly. Any way to check the head hight? Oil pump gasket is the paper thin kind. Quote Link to comment
datzenmike Posted September 14, 2015 Report Share Posted September 14, 2015 So much for herbal medicine.... get out the scalpel. 2 Quote Link to comment
Carter 71 Posted September 14, 2015 Report Share Posted September 14, 2015 I don't think 1 tower shim(.015 most) is going to cause this noise. Just my opinion Tower shim is not the cause, it's the cure, well in my case it was. Quote Link to comment
Draker Posted October 18, 2015 Author Report Share Posted October 18, 2015 So much for herbal medicine.... get out the scalpel. Welp.. got the cover off. Everything looks fine. Quote Link to comment
Draker Posted October 18, 2015 Author Report Share Posted October 18, 2015 Everything is tight.. no noticeable slop in the chain. Quote Link to comment
banzai510(hainz) Posted October 18, 2015 Report Share Posted October 18, 2015 well its been a month I though noise was gone Why is cover off? Everything looks good to me 1 Quote Link to comment
Draker Posted October 18, 2015 Author Report Share Posted October 18, 2015 well its been a month I though noise was gone Why is cover off? Everything looks good to me The only thing gone was my motivation to keep working on the car. After cleaning the garage up a bit yesterday, I figured I'd spend an hour to open it up.. found nothing. Quote Link to comment
Stoffregen Motorsports Posted October 19, 2015 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? Quote Link to comment
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