Intermittent Valvetrain Noise
06-15-2005, 03:40 PM
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Intermittent Valvetrain Noise Background info: I'm usually pretty good at diagnosing things, so when I say that my noise is in the valvetrain, it's either there, or it sounds exactly like it. I'm a member over at fullsizechevy.com, but figured I'd see if anyone has any ideas over here.
It's the 6.0L in my 2001 1500HD.
The problem: Sounds like one loose rocker arm. What's driving me crazy is that it's intermittent, and it's either really loud, or it doesn't do it at all. By really loud, I mean driving down the road the sound will bounce off of stuff.
It started 2 days ago, and I almost pulled the valve covers to check it out but it completely went away. Since then, it's been off and on lasting about 30 min. each time without regard to whether I shut the engine down and let it completely cool off or not.
I've heard about the O ring issues, but my oil pressure is constant with a minimum of about 40 psi - so I'm not convinced that could be it.
What's really confusing me is the intermittent nature of it, I've never heard this type of sound come and go. Yes, maybe a slight tick that varies with oil pressure - but not a tick that's loud as hell or nothing at all.
Any ideas?
Thanks in advance...
It's the 6.0L in my 2001 1500HD.
The problem: Sounds like one loose rocker arm. What's driving me crazy is that it's intermittent, and it's either really loud, or it doesn't do it at all. By really loud, I mean driving down the road the sound will bounce off of stuff.
It started 2 days ago, and I almost pulled the valve covers to check it out but it completely went away. Since then, it's been off and on lasting about 30 min. each time without regard to whether I shut the engine down and let it completely cool off or not.
I've heard about the O ring issues, but my oil pressure is constant with a minimum of about 40 psi - so I'm not convinced that could be it.
What's really confusing me is the intermittent nature of it, I've never heard this type of sound come and go. Yes, maybe a slight tick that varies with oil pressure - but not a tick that's loud as hell or nothing at all.
Any ideas?
Thanks in advance...
06-15-2005, 06:00 PM
#3
It sounds like you know how to tell the difference between a valvetrain related noise and one that is crankshaft related. With that assumption, I'd say you have a lifter that is turning in the guide. When it is turned, it taps loud as hell, then it flips back for a while and is normal. My engine did this as well. I ended up needing new lifter guides, new lifters, and a new cam. Good luck!
06-16-2005, 09:38 AM
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Originally Posted by Cal
It sounds like you know how to tell the difference between a valvetrain related noise and one that is crankshaft related. With that assumption, I'd say you have a lifter that is turning in the guide. When it is turned, it taps loud as hell, then it flips back for a while and is normal. My engine did this as well. I ended up needing new lifter guides, new lifters, and a new cam. Good luck!
In your opinion, is this the only possibility?
06-16-2005, 11:04 AM
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Here's my situation: I have an aftermarket extended warranty with a $100 deductible - I pay $100, they fix anything internal with the engine, tranny, whatever.
If this is what it is, then fairly soon my cam should be notched to hell, and my lifter might hopefully take a total dump and cause a rebuild to be in order. The warranty company won't authorize any major repairs if they aren't absolutely necessary, and on my 150,000 mile engine, I'd rather a complete rebuild for my $100 deductible than lifter replacement.
I think I'll sit on it for a while.
If this is what it is, then fairly soon my cam should be notched to hell, and my lifter might hopefully take a total dump and cause a rebuild to be in order. The warranty company won't authorize any major repairs if they aren't absolutely necessary, and on my 150,000 mile engine, I'd rather a complete rebuild for my $100 deductible than lifter replacement.
I think I'll sit on it for a while.
