Valvetrain problem....need help quick
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Drifting
Joined: Jan 2002
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From: Northampton Ma
Valvetrain problem....need help quick
I was just putting the finishing touches on my winter work, and started the car up. I get a loud ticking from the rocker arm on cylinder #2. The same one I had problems with last year :cuss . When I pulled the valve cover last year, I found the rocker arm was extremely loose. But I put in a new cam, lifters, springs, locks, seals, and timing chain anyway. When I was finished the motor ran perfect. So when I got the ticking last night, I pulled the valve cover again. The same rocker arm is slightly loose. I tighten it until it's snug (not over tight) and start the motor, it runs perfect for about 15 seconds and the loosen and starts ticking again, but the nut on the rocker is not backing off, telling me that this is probably some sort of lifter problem. When I pulled the lifter out last year, that one lifter was very hard to get out, while the other ones came out easily. What is going with my motor :confused: :cuss Thanks in advance :cheers:
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Joined: May 2002
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From: Gulf Coast MS
Re: Valvetrain problem....need help quick (Ryan77)
Try a new nut or maybe even double nut it so see if it stops it. If you changed cam, lifters and such, maybe check the stud its self. never seen it happen but maybe its backing out. Just a thought :seeya
Thread Starter
Drifting
Joined: Jan 2002
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From: Northampton Ma
Re: Valvetrain problem....need help quick (Vetterodder)
I also suspect a stud pulling or pehaps an oiling problem in just that one cyl.
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Joined: Jun 2001
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From: Severna Park Md
Re: Valvetrain problem....need help quick (Ryan77)
Might have wiped the cam lobe on that one. Start it with the valve cover off and check for the movement of the rocker. Compare the movement of that rocker with the others. You can hold your finger on the end of rocker and judge if theres a big difference. Is so the lobe is wiped. I also agree with the other suggestions as to nut backing off or stud pulling out. Once those crimped style rocker nuts are used and re-used theyre pretty much wasted and dont grip good anymore. The fix would be polylock locking rocker nuts. You could also pull that rocker and pushrod and check all the important areas for unusual wear. Either the ends of the pushrod or the rocker pivot and such.
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Joined: Jun 2001
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From: Severna Park Md
Re: Valvetrain problem....need help quick (Jvette73)
Also, unfortunatly, some blocks were machined out of tollerance and were put out that way. If you continue to have the same problem with lifters or wiped lobes on the same position, its possible that that lifter bore is not machined at the correct angle for proper tollerances. With smaller cams the problem will be less evident and less frequent. But when you push the limits with larger cams, the problem with bad block machining can announce itself. I hope this isnt yur problem since it would mean the block is bad.
Thread Starter
Drifting
Joined: Jan 2002
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From: Northampton Ma
Re: Valvetrain problem....need help quick (Jvette73)
Unfortuneately, the block could be the problem, as the I said before that one lifter was very hard to get out last time, but that could also mean an oiling problem. I'm going to run the motor flush through it tonight, and see if I get anywhere, but I doubt it. I'll get back to you guys on the results tommorow :sad:
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Joined: Feb 2003
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From: Elk River MN
Re: Valvetrain problem....need help quick (Ryan77)
Did you replace pushrods? A friends Nova would do that and found out there was a bent pushrod. Once the rod is bent they continue to bend rather easily making them shorter till they finally break. Also seen a wore out tip slowly chew a hole through the rocker arm. this was similar to what you described. Although if the old lifter was hard to get out last time I would probably focus on that area first. Or theres always the dreaded missing cam lobe! Go roller!
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Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,484
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From: Northampton Ma
Re: Valvetrain problem....need help quick (MN 72 454)
No, I didn't change the pushrods, but, I didn't put them back on the same cylinder they came off. I was going to put new heads on it later this year, so this just gives me a reason to buy a crate engine. I looking into the 470hp 383 from AR Racing :cool: