Need help with lifter/valvetrain diagnostic
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Burning Brakes
Joined: Oct 2006
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From: Cincinnati OH
Need help with lifter/valvetrain diagnostic
Hey guys, my motor is ticking slightly. With a stethoscope I can hear the noise in cylinder 7 right at the exhaust manifold. I pulled the valve cover off to check the springs and everything looks fine. I also noticed the plug wire was loose on cylinder 7. However, before I put everything back together I was wondering if I can check the lifters/rods/etc. without too much more teardown? I know nothing about valvetrains. I have seen them put together on Saturday morning car shows though haha. Thanks in advance for the help!
Safety Car
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You don't show any mods, so I am assuming the valve train (cam, lifters, and rocker arms) are stock.
A loose spark plug wire can make ticking sound.
If that does not fix it, remove the valve cover and see if any of the rocker arms are loose hitting the valve covers. Wiggle the rocker arms right and left and up and down. You may have to rotate the engine with the starter to make sure the valves are closed. There should be no gap between the valve and rocker arm. If there is, it could be a number of things that cause it including loose rocker arm bolt, damaged rocker arm, bent push rod, etc.
A loose spark plug wire can make ticking sound.
If that does not fix it, remove the valve cover and see if any of the rocker arms are loose hitting the valve covers. Wiggle the rocker arms right and left and up and down. You may have to rotate the engine with the starter to make sure the valves are closed. There should be no gap between the valve and rocker arm. If there is, it could be a number of things that cause it including loose rocker arm bolt, damaged rocker arm, bent push rod, etc.
Last edited by Mez; Sep 3, 2010 at 09:14 AM.
Le Mans Master
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Thread Starter
Burning Brakes
Joined: Oct 2006
Posts: 1,006
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From: Cincinnati OH
You don't show any mods, so I am assuming the valve train (cam, lifters, and rocker arms) are stock.
A loose spark plug wire can make ticking sound.
If that does not fix it, remove the valve cover and see if any of the rocker arms are loose hitting eh valve covers. Wiggle the rocker arms right and left and up and down. You may have to rotate the engine with the starter to make sure the valves are closed. There should be no gap between the valve and rocker arm. If there is, it could be a number of things that cause it including loose rocker arm bolt, damaged rocker arm, bent pushrod, etc.
A loose spark plug wire can make ticking sound.
If that does not fix it, remove the valve cover and see if any of the rocker arms are loose hitting eh valve covers. Wiggle the rocker arms right and left and up and down. You may have to rotate the engine with the starter to make sure the valves are closed. There should be no gap between the valve and rocker arm. If there is, it could be a number of things that cause it including loose rocker arm bolt, damaged rocker arm, bent pushrod, etc.
Thread Starter
Burning Brakes
Joined: Oct 2006
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From: Cincinnati OH
Safety Car
Joined: Jun 1999
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From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Yes the valvetrain is stock. One of the rockers on cylinder three is loose. It wiggled side to side a little. Do you think I should measure valve lash? Is that what you mean by the gap between the valve and the rocker? Do I check this with the spring decompressed? Is the some sort of feeler gauge for this and do you know the specs? Should I start the motor open and close the valves or just turn the crank by hand. Ots just me working on the car and I don't know if I can stop start it with that kind of precision. Thanks!!
With hydralic lifters, there is not gap. The lifter has to be preloaded. The procedure is to set it to zero lash then turn the rocker arm hold down bolt to 22 ft/lbs which be between 1/4 turn and one full turn. Zero lash is when the rocker is tight enough that you can't really spin the push rod.
This is done with the cam on the base circle which means the valve is closed. If the rocker moves a little side to side with some force, thats OK but there definitely should not be any gap whatsoever between the rocker and valve tip.
Safety Car
Joined: Jun 1999
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From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
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St. Jude Donor '10-'11-'12
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Burning Brakes
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From: Cincinnati OH
Ok guys I checked the valve lash and the was no gap. I cleaned up the plugs and made sure they were tight. I put everything back together and I still here the tick. Just listening with my ears I can't hear it standing over the motor but can hear it very well under the car. I checked and there are no exhaust leaks anywhere. If I'm under the car the sound seems like it's coming from near the oil filter. Could this be a lifter?
Fwiw my car has a lot of miles. I'm at 115,000 and I drive the car hard a lot. Actually when I first heard this tick was after a hard launch then a first to second gear blast when the motor was not completely warmed up yet. Oh And my ride is a c5 sorry I'm in the wrong forum but apples to apples I guess.
I'll get a vid of soon to hear. Thanks.
Fwiw my car has a lot of miles. I'm at 115,000 and I drive the car hard a lot. Actually when I first heard this tick was after a hard launch then a first to second gear blast when the motor was not completely warmed up yet. Oh And my ride is a c5 sorry I'm in the wrong forum but apples to apples I guess.
I'll get a vid of soon to hear. Thanks.
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St. Jude Donor '10-'11-'12
Lifter tick is always possible, you wouldn't be the first to have an issue with the stock lifters on a stock setup. But near the oil filter from underneath?
I would expect to hear it more up top but noise does travel.
I had a lose substrate in a hi flow cat once that made a rapping sound just like rod knock. On video you would have sworn it was but after some good investigation with the car on tjwongs lift we found the issue. The sound traveled pretty good though and until we had the car on a lift we could not find it's source. Tom was banging the exhaust pipes with his hand and it made the noise.
I would expect to hear it more up top but noise does travel.
I had a lose substrate in a hi flow cat once that made a rapping sound just like rod knock. On video you would have sworn it was but after some good investigation with the car on tjwongs lift we found the issue. The sound traveled pretty good though and until we had the car on a lift we could not find it's source. Tom was banging the exhaust pipes with his hand and it made the noise.
