Motor sounds like marbles
04-01-2005, 02:34 AM
#1
On The Tree
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: norcal
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
Motor sounds like marbles Today I noticed my oil pressure was down, my first thought was oh **** but then I thought let me check the oil level it was really low(I had a bad oil filter seal so it dripped occassionally).I changed the oil put some mobil1 5w30 syn. and then took it out and drove around.My oil pressure was back up to 40+ at idle so was happy.I got on it a few times and evry thing seemed normal.Well a block from my street I got on it. I was in 2nd it downshifted to 1st and then I got moving pretty good and it shifted to 2nd I let off the gas braked to turn onto my street and the car died.I put it in neutral and restarted it as i was coasting and it started idling at 2000 rpm and making sounds like marbles in the motor.I pulled the car in the garage shut off inspected it and started it back up it now idles normal but still sounds like marbles.One more thing I did notice to battery gauges bouncing towards below 13.Am I in deep ****? one last detail the SES light is NOT on!
Last edited by 98cobrakillata; 04-01-2005 at 02:48 AM. Reason: Forgot one detail
04-01-2005, 06:20 PM
#5
On The Tree
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: norcal
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by The Alchemist
Looking at your cam and spring combo, I'd say you broke a spring or maybe a rocker arm spilled the needle bearings.
It does sound like a loud sewing machine. The werd thing is the sound is there for a while then goes away, then comes back again.It will be very consistant then stops and becomes unconsistant for a while.
Trending Topics
04-01-2005, 08:30 PM
#8
TECH Enthusiast
Join Date: Nov 2004
Location: Red Stick, LA
Posts: 659
Likes: 0
Received 0 Likes
on
0 Posts
If you pull the valve covers and don't see anything, you can get someone to crank the car while you watch the rockers (with the valve covers off) You might get a little oil everywhere(maybe not), but you will see if a lifter is not working properly. It will be out of sync. I did it on a SBC before. It could be a bearing though.
04-02-2005, 01:16 AM
#12
TECH Regular
Join Date: Nov 2004
Location: Reno, NV
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
What was it like when it died? No fuel/spark? When it died, did it start right up without any trouble? You also state that the battery gauge is indicating low. Are you sure the alternator didn't self-destruct? Get that stethoscope...
I would inspect the flex-plate first (see below). Or...
With the mods you have, you probably know all of this:
While the covers are off, you may as well pull your plugs and inspect the rockers. Makes it easy to turn the engine by hand with the plugs out. Put a socket on the balancer and (have someone) turn the engine over slowly. Inspect the motion for each set of valves, one cylinder at a time, through all four strokes. Pay close attention to the geometry...making sure the push rods and valve stems are not bent. Make sure the lash is set properly...no slop between the rocker, valve and push rod. I don't know what the lash should be for the LSx...probably one-quarter turn passed zero lash. Check your FSM or maybe someone on the list will respond.
You will inspect lash when the rockers come to rest anywhere along the compression (squeeze/bang) stroke after intake closes and before the exhaust valve starts to open. Try and move the push rod with your fingers. You should not be able to move it up or down. Then, make sure the rockers are not moving and both valves are closed (compression TDC would be best). You can slip a plastic rod into the spark plug hole to make sure the piston is at TDC. Just be sure the rod is long enough not to fall in. Once you know exactly what the lash should be for your engine, you can loosen/remove the bolt holding the rocker to the stud (one at a time). While loostening the bolt, count the number of turns until lash is detected. Inspect the rocker. Inspect the stud and bolt. Inspect the push rods. Inspect the spring and see if it's all in one piece. Reassemble setting the proper lash and check the next one.
If all is well, unfortunately, it could be a lot of different things. The first (other) thing that comes to mind is possibly a cracked flex-plate. That can sound like a lifter. If you have no obvious effect on performance and good oil pressure, this could be a suspect. Get a mechanic's stethoscope ($5 at AutoZone) and locate the noise (engine running). If it's the flex-plate, the noise will be much louder near the trans bell housing. And, a lifter only moves once every two engine rotations. The flex-plate obviously rotates with the crank. So, if the noise is in sync with the engine, it's probably not valve related. If the noise is half-speed of the engine rpm, it very well could be noise from a valve, cam-driven or cam associate.
If you suspect the flex-plate, jack the car up on stands and get under there. If the setup is like most GM (I have never been under an F-body), there should be a cover with four bolts that you can remove to see the flex-plate. (Folks?) Again, have someone turn the engine over and inspect the flex-plate (or you could try turning the engine with a wrench on the flex-plate). Use a powerful lamp or flashlight. Cracks in flex-plates can be hard to see
Good luck and let us know what you find.
I would inspect the flex-plate first (see below). Or...
With the mods you have, you probably know all of this:
While the covers are off, you may as well pull your plugs and inspect the rockers. Makes it easy to turn the engine by hand with the plugs out. Put a socket on the balancer and (have someone) turn the engine over slowly. Inspect the motion for each set of valves, one cylinder at a time, through all four strokes. Pay close attention to the geometry...making sure the push rods and valve stems are not bent. Make sure the lash is set properly...no slop between the rocker, valve and push rod. I don't know what the lash should be for the LSx...probably one-quarter turn passed zero lash. Check your FSM or maybe someone on the list will respond.
You will inspect lash when the rockers come to rest anywhere along the compression (squeeze/bang) stroke after intake closes and before the exhaust valve starts to open. Try and move the push rod with your fingers. You should not be able to move it up or down. Then, make sure the rockers are not moving and both valves are closed (compression TDC would be best). You can slip a plastic rod into the spark plug hole to make sure the piston is at TDC. Just be sure the rod is long enough not to fall in. Once you know exactly what the lash should be for your engine, you can loosen/remove the bolt holding the rocker to the stud (one at a time). While loostening the bolt, count the number of turns until lash is detected. Inspect the rocker. Inspect the stud and bolt. Inspect the push rods. Inspect the spring and see if it's all in one piece. Reassemble setting the proper lash and check the next one.
If all is well, unfortunately, it could be a lot of different things. The first (other) thing that comes to mind is possibly a cracked flex-plate. That can sound like a lifter. If you have no obvious effect on performance and good oil pressure, this could be a suspect. Get a mechanic's stethoscope ($5 at AutoZone) and locate the noise (engine running). If it's the flex-plate, the noise will be much louder near the trans bell housing. And, a lifter only moves once every two engine rotations. The flex-plate obviously rotates with the crank. So, if the noise is in sync with the engine, it's probably not valve related. If the noise is half-speed of the engine rpm, it very well could be noise from a valve, cam-driven or cam associate.
If you suspect the flex-plate, jack the car up on stands and get under there. If the setup is like most GM (I have never been under an F-body), there should be a cover with four bolts that you can remove to see the flex-plate. (Folks?) Again, have someone turn the engine over and inspect the flex-plate (or you could try turning the engine with a wrench on the flex-plate). Use a powerful lamp or flashlight. Cracks in flex-plates can be hard to see
Good luck and let us know what you find.
Last edited by Builder; 04-02-2005 at 01:32 AM. Reason: Question...
04-02-2005, 01:47 PM
#14
TECH Enthusiast
Join Date: Jul 2002
Location: Austin, TX
Posts: 611
Likes: 0
Received 0 Likes
on
0 Posts
yah check the flexplate. there is only one small 10mm bolt that holds the little plastic cover to access the flexplate. take that off and either have someone crank the motor at the crankshaft pulley or if you are alone use a bigass screwdriver and pry the flexplate, rotating it 360 degrees to inspect it.
when i broke my flexplate it was topping out 3rd gear...not only did it crack, it cracked and bent and was scraping the bellhousing of the transmission or the block. it sounded horrible metal scrapping metal. no ses codes of course.
your problem doesnt seem like its the flexplate from your description. i don't see why the car would die from it and it shouldn't effect the idle speed either, but check it just to be sure.
check the flexplate, if that is ok then pull the valve covers...and go from there..
good luck
when i broke my flexplate it was topping out 3rd gear...not only did it crack, it cracked and bent and was scraping the bellhousing of the transmission or the block. it sounded horrible metal scrapping metal. no ses codes of course.
your problem doesnt seem like its the flexplate from your description. i don't see why the car would die from it and it shouldn't effect the idle speed either, but check it just to be sure.
check the flexplate, if that is ok then pull the valve covers...and go from there..
good luck
04-02-2005, 03:49 PM
#15
On The Tree
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: norcal
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
Update!!!! I started the car with no valve cover on. Come to find out I am not getting ANY oil to to DRIVER side head and very little to a pass side head.My oil prssure at idle is about 55psi and at 2000 rpm it is 70 psi. Help any suggestions would be great!!!!!!!!!!!!
04-02-2005, 04:16 PM
#16
On The Tree
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: norcal
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
NOW, oil is coming out the rocker oilling hole.WTF??????marble tapping will go away and then come right back.
Last edited by 98cobrakillata; 04-02-2005 at 04:29 PM.
04-03-2005, 06:17 AM
#19
Launching!
iTrader: (8)
Join Date: Nov 2002
Location: tx
Posts: 252
Likes: 0
Received 0 Likes
on
0 Posts
Your story sounds just like mine. Low oil pressure, added oil, tested it, car died, got it started but also making noise, blah, blah, blah. End result was a spun rod bearing.
04-03-2005, 01:31 PM
#20
On The Tree
Thread Starter
iTrader: (2)
Join Date: Sep 2004
Location: norcal
Posts: 143
Likes: 0
Received 0 Likes
on
0 Posts
can a rod bearing be changed in the car? I changed rod bearings and crank under the car in an LT1 fbody.I think the LS1 oil pan looked harder to get off under the car so I was just wondering.I was hoping it wasn't the botttom end.