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Discussion Starter · #1 ·
Hello,
In short I was tuning my engine (ignition timing) and took it out for a spin, warmed it up and floored it one time. Nothing excessive just from about 10mph up to 60. It has the original power glide transmission.
All of a sudden I heard a slight ticking sound from the engine, left side cyl#1.
It almost sounds like a spark plug wire arcing to ground.
I believe I must have spun the connecting rod bearing on cyl#1? The reason for this diagnosis is, when I remove the spark plug wire from this cylinder the noise goes away.
Since it will require a lot of work and expense to resolve, is there any chance it could be anything other than the bearing or piston wrist pin? My hope a lifter or sticky valve...
All input would be appreciated. The Nova is all original and had maybe 3000 miles on the prof engine rebuild. It should have held up. Wondering if the timing slightly off caused any undue stress??
thanks in advance.
Dave
 

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You check your exhaust gasket? Is the noise really mechanical or is it difficult to determine? drain your oil in a clean pan and see what comes out. That's one method to see if something bad happened but not definitive... Has it backfired at all at any time since the rebuild? That can weaken a loose exhaust gasket...
 

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I might add, whatever your issue ends up being, unless you use copper or aluminum sandwich-type header/exhaust gaskets, typically, everything on the exhaust, following a few full-heat cycles, should be re-torqued and checked for leaks and tightness. Dissimilar metals and gasket materials will, upon a few heat cycles, cause the gaskets to fail miserably, especially if you use fibrous gaskets.
 

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Discussion Starter · #4 ·
You check your exhaust gasket? Is the noise really mechanical or is it difficult to determine? drain your oil in a clean pan and see what comes out. That's one method to see if something bad happened but not definitive... Has it backfired at all at any time since the rebuild? That can weaken a loose exhaust gasket...
I didn鈥檛 check the exhaust gasket. It is tough to determine if mechanical,i.e. or something else like the gasket or arcing? It did actually backfire at least once while I was adjusting the timing during startup before I took it out for a test ride but it didn鈥檛 make any noise at that point.

It鈥檚 worth checking the gasket but it has the original exhaust manifolds and new gaskets look good , tight from topside. Oil looks good on the dip stick but I will drain and check that too if the exhaust gasket isn鈥檛 the problem.

I had a spun bearing on another vehicle yrs ago it sounded more of a dull or quieter clanking vs this ticking or tapping sound. Plus when I drained the oil on that engine there were plenty of metal particles that confirmed the prob. But that engine rebuild was a cheap kit from overseas and I was really beating on it so understandable. This is all GM iron. Thanks for the input appreciate it. I鈥檒l post my findings as I get time to work on it.
 

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Worth pulling a rocker cover off the head to see if your valve train is still intact too. Even though it only sounds when you have spark, could be a really weak valve spring exacerbated by the combustion cycle. Go from easiest (exhaust gasket) to most difficult (pull motor) in that order. I've pulled a few out in my day when it wasn't what I thought... time consuming and embarrassing at least, but happily found it was not catastrophic... Easy fix! Fingers crossed for you!! :)
 

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Discussion Starter · #7 ·
Hello Andy?

I owe you a beer or two馃嵒!
I checked the exhaust manifold gasket on the left side of my engine this morning and sure enough after removing the alternator to get at it I found the outer bolt on the manifold against cyl#1 was a little loose. I couldn鈥檛 believe it as from the top view looking down at the gasket everything looked good, tight etc. I loosened the entire manifold to check all gaskets and re-torqued as they were fine. Fired her up and she sounds great! What a relief.
Again thank you for your time, expertise and positive thoughts, really do appreciate it. All the Best.

Also thanks to this site, it鈥檚 nice to be able to communicate with fellow car enthusiasts and get stuff done! It鈥檚 all good馃槈馃憤
 

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Discussion Starter · #8 ·
Worth pulling a rocker cover off the head to see if your valve train is still intact too. Even though it only sounds when you have spark, could be a really weak valve spring exacerbated by the combustion cycle. Go from easiest (exhaust gasket) to most difficult (pull motor) in that order. I've pulled a few out in my day when it wasn't what I thought... time consuming and embarrassing at least, but happily found it was not catastrophic... Easy fix! Fingers crossed for you!! :)
Worth pulling a rocker cover off the head to see if your valve train is still intact too. Even though it only sounds when you have spark, could be a really weak valve spring exacerbated by the combustion cycle. Go from easiest (exhaust gasket) to most difficult (pull motor) in that order. I've pulled a few out in my day when it wasn't what I thought... time consuming and embarrassing at least, but happily found it was not catastrophic... Easy fix! Fingers crossed for you!! :)
Hello Andy?

I owe you a beer or two馃嵒!
I checked the exhaust manifold gasket on the left side of my engine this morning and sure enough after removing the alternator to get at it I found the outer bolt on the manifold against cyl#1 was a little loose. I couldn鈥檛 believe it as from the top view looking down at the gasket everything looked good, tight etc. I loosened the entire manifold to check all gaskets and re-torqued as they were fine. Fired her up and she sounds great! What a relief.
Again thank you for your time, expertise and positive thoughts, really do appreciate it. All the Best.

Also thanks to this site, it鈥檚 nice to be able to communicate with fellow car enthusiasts and get stuff done! It鈥檚 all good馃槈馃憤
 

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Joined
1,372 Posts
Hello Andy?

I owe you a beer or two馃嵒!
I checked the exhaust manifold gasket on the left side of my engine this morning and sure enough after removing the alternator to get at it I found the outer bolt on the manifold against cyl#1 was a little loose. I couldn鈥檛 believe it as from the top view looking down at the gasket everything looked good, tight etc. I loosened the entire manifold to check all gaskets and re-torqued as they were fine. Fired her up and she sounds great! What a relief.
Again thank you for your time, expertise and positive thoughts, really do appreciate it. All the Best.

Also thanks to this site, it鈥檚 nice to be able to communicate with fellow car enthusiasts and get stuff done! It鈥檚 all good馃槈馃憤
@DavidM That's AWESOME NEWS!!! So happy that was such an easy fix!!! Good to have you aboard and have so many other awesome people here too!!! I have learned a lot in my many years and am still learning daily! My current principle is KISS. Keep It Simple Stupid! Live it, Love it, Embrace the suck!! :)

Again, awesome news!!!

~Andy
 
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