What is this annoying noise !!!!!

[shadowdude]

Ok i took my shadow to a shop ,three techs had a look and listen plus before that same day i went to the engine rebuilders as well.No one knows or even has a guess at what this annoying ticking sound is.The thing that throws us off is the fact you can stop the noise by plugging the fresh air line on the PVC.watch the video to see what i mean.I am running the pcv in the way you see but will be tidied up once i can figure out this annoying noise.I checked the top end and bottom end visually very very closely and can not see anything out of the norm, with a stethascope i can some what pin point it to the rear main oil seal area,yet like i say with pan off i cant see even the smallest sign od damage of what is causing it.Motor is fresh with only 3500 since a professional rebuild.Got any ideas.This is driving me super friggen insane !!!!

[forcedfedmopar]

does it go away when you open your filler cap or pull the dip stick? if so you have a PCV problem.

[shadowdude]

Nope ,remove the oil cap still there,and take the dip stick out still does it.Only when i do that plugging the vent thing ...then thats when it goes away.

[shackwrrr]

loose oil baffle in the valve cover?

[shadowdude]

I wish ,nope checked that as well.Here is what i checked,i tell you this one is the most strangest pain the --- ever.I checked....VC baffle,valve springs ,retainers ,roller rockers ,lifters,checked for foreign stuff in oil galleries ,PCV itself and saw nothing,even took the pcv out of the loop still did it.Took the oil pan off and had a look up at cylinders for marks from damage ..nothing ,those are A1.Rods and mains bearings look great no visible signs of wear or damage, no rod play except for normal little side to side on journal.Checked around torque converter for possible contact or loose piece ,bolt maybe or again foreign object maybe.Oil pump pick up for debris i mean i went over it with i fine tooth comb and thats whats stumping me ,some thing has to be making that noise.If it was valve train or bottom end it would do it regardless of the pcv plugging deal i do.I mean how does one stop bottom end or valve train noise by plugging the vent.

[raccoon]

cracked flex plate?

its an auto right?

[shadowdude]

Yep an auto .Cant say no because cant see around close to the actual flex plate bolts ,but from what i can see of the rest of the flex plate from underneath with splash plate off and hand rotating the engine no i don't see any cracks.Lets say that it was though, then why does it stop when i do that plugging of that pipe vent ?

[shadowdude]

OH OH .. this is not good then , not many responses so far guess this one may be a impossible find ? I may have to start tearing the car apart again to track it down...this sucks i am really starting to despise this car.
15 days before the big car show ...what else is new.

[bakes]

cracked flex plate or loose TC bolts mabe.

[shadowdude]

Just came in from the garage and have the oil pan off again and took front motor mount off and back bracket as well to give more visual space.I have looked around the rear main area because thats where it sounds like it is coming from.I cant not see the area around the flex plate bolts but as you all know you can see most of the flex plate besides and i cant see any cracks, again i am not saying it isn,t that but if it was why does plugging the tube like i do make it stop ?.Torque Converter bolts are nice and tight checked those.Went on all the rod bolts and mains bolts and they are tight as well...that was grabbing for straws but i am stumped to no end and trying whatever now.I really don't want to pull the trans out ether unless i am sure that there is something wrong.I am about ready to put up 50 bucks for the solution that fixes this super pain in the ***.Supposed to be taking it in soon for new tires but that is gonna have to wait .Well back out to the garage....piece of 'blank' car

[shackwrrr]

loose bolt holding the flexplate to the crank? Those go through into the crankcase. any leaks from the rear main area?

[turbovanman²]

Cracked flexplate or excessive wrist pin clearance.

[raccoon]

why does plugging the tube like i do make it stop ?

changes the engines RPM slightly causing the odd harmonic vibration to go away? lol i dunno.

[JohnnyIroc]

same problem here
http://www.nissanforums.com/b11-b12-...lve-cause.html

[Force Fed Mopar]

Bad PCV valve maybe.

Edit: nvm, just read what you checked. So that tube you plug runs to the PCV elbow?

[turbovanman²]

Bad PCV valve maybe.

Edit: nvm, just read what you checked. So that tube you plug runs to the PCV elbow?

Its open, IE fresh air, just like the stock setup but no filter.

changes the engines RPM slightly causing the odd harmonic vibration to go away? lol i dunno.

This is why I think loose wrist pin, plugging up the vent cause's pressure to build in the crank case, thus taking a bit of load off the wrist pin, maybe BS but its a theory, lol!

[88_pacifica]

quick question: you said professional rebuild about 3500 ago. What type of rings were used and are they chromemoly's? Maybe they never sealed fully on one of the cylinders or there is a leakdown on just one of the cylinders. I am sure you or the techs did a quick leakdown test correct?

While it does sound like a valvetrain issue, it is not "ticking" fast enough to make me think that's what it is. I assume the head was totally gone through as well?

Sure sounds like there is some sort of "escape point" around the piston/rod(bottom end) that is providing a "pulse" that might be minimal when the pressures are at a certain point and "could be" temporarily pressuring the case in some way when it is blocked. While I AM grasping at straws, I would look into a leakdown test since that's an easy test. Just my .02...

Also,

[shadowdude]

Man time can fly when you in the garage swearing ...ahem i mean trouble shooting.To address in order ( and sorry for this long post )...first no leaks at rear main seal,and took out torque converter bolts and pushed the converter back to see if there was a flex plate bolt loose or something,turned the engine over by hand ,heard nor saw anything in that area.I had the pan off and reached up and tried to move each rod by hand and no matter how i move them or push them there is no play at all.I would "assume" that if there was enough play for that slight difference in pressure i would be able to feel it or even see if there was signs of bad wear on them.They are new JE pistons,pins and retainers put in the rebuild and the rings are file fitted.I thought about rpm change as well but listen to it i cant hear a change ,lol..i dunno .Not a BS theory Simon cause i went down there and remove the pan twice just to reassure myself it was checked.Like i say i never saw even a tiny bit of wear or signs of anything bad down there.Even the cylinder walls are like new still.The rings are file fitted and the block was properly done with the right stones and done as well with a torque plate.I checked the compression ...oh about 4 or 5 days ago because i though maybe a ring was broke and banging around but the compression it dead on 150 psi across the block not even out 1 psi.I ordered some lifters as it has 196 000 kms on the stock 1991 roller cam ,rockers and lifters as well i took the baffle off the VC and am going to reseal it with that RTV trick.Myself grabbing for straws but i am hoping that maybe the lifters are worn a bit and the baffle not sealed right is amplifying the ticking .LOL thats a huge long shot but i might as well hope right.If that doesn,t work then i will take the pan back of and remove the rod caps and check the bearings for any wear and same time with the piston free of any pressure check the pins.Have ARP main studs and rod bolts with new 20 over clevitte as well.All the good stuff went into this build.Now i got to go get some supper.Thanks guys for sticking with me on this one.

[GLHNSLHT2]

someone leave a socket in the engine somewhere? It's NOT a cracked flexplate. A cracked plate would get louder when you revved it like a bad rod does. It's also impossible to see the crack without taking the whole plate off as it cracks behind the washer on the crank. Sounds like a socket ratting around in your head somewhere on my speakers. What if you take the PCV system totally off and just plug the pipe coming out of the intake so you don't get a high idle. Still make the noise then?

[GLHNSLHT2]

if you're gonna swap lifters now is a time to put in some MP lifters for a 2.4 and some spacers for them. Just search for PT lifters on teh forums.