I can hear some Knocking!!! Nooooooo!
#1
06-01-2012, 08:45 PM
I can hear some Knocking!!! Nooooooo!
ok so.... today i was on the highway and i started to hear wat seemed some rattling. as if something was loose. I pulled over at a gas station and opened the hood to find out that there is some knocking going on!
I got home and let the engine cool down a bit, took off the valve covers and found some rockers loose. 3 of them on the driver side where loose to where i can pull them back/up?? is this ok?? also as i was turning over the engine with a ratchet i noticed that some rockers would not stay down when they compressed the springs. soon as the spring was compressed i let off the ratchet and i saw the rockers come back up while others kept the spring compressed!!?? (remember this 20 mins afters shutting of the motor). When its at idle the knocking is at minimum and tends to fade away but then comes back shortly... now when i rev it, you can definitely hear it. The higher i rev the louder it gets. it is a pretty solid knock and not a ticking. So..wat do you guys think is causing the knocking? lifters? or piston? what kind of knocking? metal to metal? or detonation from the "bad" lifters?
oh and my gas millage has also gone down to like 8mpg!! i burned 1/4 of a gas tank in just under 1hr driving around town mostly being stops.. i have never burned this much gas. i dont know if this a symptom of my problem but i dont like it!
I got home and let the engine cool down a bit, took off the valve covers and found some rockers loose. 3 of them on the driver side where loose to where i can pull them back/up?? is this ok?? also as i was turning over the engine with a ratchet i noticed that some rockers would not stay down when they compressed the springs. soon as the spring was compressed i let off the ratchet and i saw the rockers come back up while others kept the spring compressed!!?? (remember this 20 mins afters shutting of the motor). When its at idle the knocking is at minimum and tends to fade away but then comes back shortly... now when i rev it, you can definitely hear it. The higher i rev the louder it gets. it is a pretty solid knock and not a ticking. So..wat do you guys think is causing the knocking? lifters? or piston? what kind of knocking? metal to metal? or detonation from the "bad" lifters?
oh and my gas millage has also gone down to like 8mpg!! i burned 1/4 of a gas tank in just under 1hr driving around town mostly being stops.. i have never burned this much gas. i dont know if this a symptom of my problem but i dont like it!
Last edited by sinus19; 06-01-2012 at 08:55 PM.
#3
06-01-2012, 09:45 PM
no dont say that.. One of my valves did drop about a month ago and the piston slapped it back up leaving a dent mark on the piston. Its not deep and its more of a scratch then a dent. Sooo i hope its not the rod on that piston...it could be though. However i did get the head fixed and i think the piston/rod are still not very happy. I might have just damaged them. and if so how come it took a while for the knocking to appear?
#5
06-02-2012, 09:05 AM
i'm not exactly sure what's going on, but, one thing at a time.
the lifter chamber pumps up with oil pressure to become semi-solid. with the engine not running and no oil pressure, the lifter can collapse, which shortens the push rod and allows the valve spring to close the valve and creates looseness in the valve train. i don't think yours should collapse that far or that fast, but we'll see.
is the rocker arm stud or nut loose?
anything wrong with the push rod, or where its captured?
was it worked on recently?
has it been ok since then?
what was the cause of the valve dropping?
did it break or did a valve spring break? need to know.
did the timing chain slip or break?
a light hit from the piston might not hurt the piston, but can bend the valve and require its replacement. i would not expect this to hurt the rod bearing, but a hard hit or hydrolock can bend a rod.
use a short piece of pipe, iron or pvc, as a stethoscope and follow the noise to its deepest source. see if its lifters/cam, or bottom end crank, or valve train. be very careful of moving parts especially belts...
does the knock increase with rpm? does it silence/fade after a modest rpm of 1000 or 1500
and give us the full story/history of what's been broken and/or repaired in the last 6 months.
i just re-read your signature with cam/heads, etc... did you do that work or have it done? has it run right since the cam/heads? how long?
the lifter chamber pumps up with oil pressure to become semi-solid. with the engine not running and no oil pressure, the lifter can collapse, which shortens the push rod and allows the valve spring to close the valve and creates looseness in the valve train. i don't think yours should collapse that far or that fast, but we'll see.
is the rocker arm stud or nut loose?
anything wrong with the push rod, or where its captured?
was it worked on recently?
has it been ok since then?
what was the cause of the valve dropping?
did it break or did a valve spring break? need to know.
did the timing chain slip or break?
a light hit from the piston might not hurt the piston, but can bend the valve and require its replacement. i would not expect this to hurt the rod bearing, but a hard hit or hydrolock can bend a rod.
use a short piece of pipe, iron or pvc, as a stethoscope and follow the noise to its deepest source. see if its lifters/cam, or bottom end crank, or valve train. be very careful of moving parts especially belts...
does the knock increase with rpm? does it silence/fade after a modest rpm of 1000 or 1500
and give us the full story/history of what's been broken and/or repaired in the last 6 months.
i just re-read your signature with cam/heads, etc... did you do that work or have it done? has it run right since the cam/heads? how long?
Last edited by dhvaughan; 06-02-2012 at 09:07 AM.
#6
06-04-2012, 10:56 AM
All of the work i did my self, It ran fine for a month before the Valve dropped in the new heads. The reason why the valve dropped was because i didnt check for clearance on the Bottom of the Rocker to the top/edge of the Retainer on the Spring. the first time i adjusted the rockers, everything checked out, but after re-adjusting them at 600 miles, i didnt bother to check for clearances again. So over time the retainer clip was wearing out because the spring was being compressed from the side and on top causing it to eventually blow out, thus dropping the valve. I never really heard a particular sound because all of the rockers had bit of a ticking which i thought was normal and the truck ran fine.
When I took the Heads off i found that the piston had been scratched from hitting the valve. So what i did was bought a wiring cup for my drill and wired brushed all of the pistons heads to remove all of the built up carbon and junk (left them nice and polished) to better see any other damages.
A month passed by and i finally got my Heads back from Clearwater (since they covered all of the damage) they put all new valves with higher/longer stems so that the rockers wouldnt hit the retainer along with new springs and the whole shebang. I went ahead and put them back on using the same head gasket (they look in good shape) with some gasket maker to be safe. I ran it for 3 days and on the 4th day i was gonna change its oil.. unfortunately it didnt make it to the 4th day... and thats where i am now...
I took the intake manifold off and checked all of the lifters and rods along with the rockers, everything seems find in that department. Timing also seems find because there was never any backfiring (intake nor exhaust). However! i did find tons of metal shavings all over the valve valley! some the size of your pinky's nail. I also found found the oil being really runny. I looked at it closely and noticed that it had some water in it, and well Im sure you guys can imagine what the watery oil can do to bearings right? sooo.. im pretty sure the motor is shot!
My solution: I got a motor of a 2nd Gen with 18k miles (its of a wrecked 96 or 98 2nd Gen Truck which was new at the time!) for only $600. Bad thing is that it has been sitting at my friends shop for about 10 year, I hope it still turns and the bearing arnt in bad condition. Im going to swap motors and transfer my Heads, Cam, and Valve train and the rest of my Bolt-ons from my currnet motor on to the 2nd gen and put it all in.
When I took the Heads off i found that the piston had been scratched from hitting the valve. So what i did was bought a wiring cup for my drill and wired brushed all of the pistons heads to remove all of the built up carbon and junk (left them nice and polished) to better see any other damages.
A month passed by and i finally got my Heads back from Clearwater (since they covered all of the damage) they put all new valves with higher/longer stems so that the rockers wouldnt hit the retainer along with new springs and the whole shebang. I went ahead and put them back on using the same head gasket (they look in good shape) with some gasket maker to be safe. I ran it for 3 days and on the 4th day i was gonna change its oil.. unfortunately it didnt make it to the 4th day... and thats where i am now...
I took the intake manifold off and checked all of the lifters and rods along with the rockers, everything seems find in that department. Timing also seems find because there was never any backfiring (intake nor exhaust). However! i did find tons of metal shavings all over the valve valley! some the size of your pinky's nail. I also found found the oil being really runny. I looked at it closely and noticed that it had some water in it, and well Im sure you guys can imagine what the watery oil can do to bearings right? sooo.. im pretty sure the motor is shot!
My solution: I got a motor of a 2nd Gen with 18k miles (its of a wrecked 96 or 98 2nd Gen Truck which was new at the time!) for only $600. Bad thing is that it has been sitting at my friends shop for about 10 year, I hope it still turns and the bearing arnt in bad condition. Im going to swap motors and transfer my Heads, Cam, and Valve train and the rest of my Bolt-ons from my currnet motor on to the 2nd gen and put it all in.
Last edited by sinus19; 06-04-2012 at 11:16 AM.
#7
06-04-2012, 11:07 AM
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#8
06-04-2012, 12:20 PM
Yea it is lol.. I am not really gonna do the swap my self (im a college student and i dont have all of the resources or time to do it my self), I'lll have a certified mechanic (he used to do professional drag racing) do the swap. I did ask him if he could pull the pan and check it out before he puts all of the bolt-ons, He said he would and possibly pull a rod or two for checking as well. it should take him 3-4 days to do the whole swap according to him.