What's this mean?
What's this mean?
- Thread starter DrDoc
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hagar
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Well, you could pull spark plug wires one at a time to see if it stops on the affected cylinder.
Otherwise, a long screwdriver or stethoscope to see where it originates from.
Otherwise, a long screwdriver or stethoscope to see where it originates from.
DrDoc
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Yeah, I'm leaning an ignition issue, going to pull plugs and see what I see. First plug out seems darker than I'd expect.. I'll post a pic soon
DrDoc
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Ouch - Its hard to say over the internet, but I'd listen by the oil pan to see if it's a rod, or look for a front end physical clearance issue.
Also, power steering pump or oil low?
Also, power steering pump or oil low?
DrDoc
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It's on the top end, near the rear. I've only gotten plug 5 and 6 out so far, 5 looks good, 6 is black and full of carbon. I've been meaning to do plugs so will get the rest out and try that. Hopefully I'll know more tomorrow (busy weekend here)
DrDoc
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What’s the exhaust look like?
That sounds like a valve to piston slap
I’d be checking cylinder pressures before idling it any more
That sounds like a valve to piston slap
I’d be checking cylinder pressures before idling it any more
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Meant to add if the plug looks sticky black goo it’s more than likely head gasket related which can get worse sitting overnight in cold temps.
Exhaust port will get gummed up and hang open.
The time of the sound and tone is off for a lifter- not sure what your idle speed is
Exhaust port will get gummed up and hang open.
The time of the sound and tone is off for a lifter- not sure what your idle speed is
DrDoc
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Plug was more dry crusty black, idle speed in the video was around 1800 since it was still cold (about 30 f in the garage this morning). Drove fine last night and started up this morning with that noise
DrDoc
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Was the air filter on last night? I know it’s not in the video. Mouse could have crawled in there
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Super8mm
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Start a heart transplant mid November with LS1 and SM465 :-)
Sounds like it is making the noise 2 times a second, I would think that maybe in the valve train?? it does not sound fast enough to be every revolution but maybe every 4 th rev???
DrDoc
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Update: got all the plugs out and did a compression test. Compression was pretty even and all other plugs besides #6 looked good to me. When doing the compression test with all plugs removed I still heard a noise when testing #6.
Next step to pull the valve cover and look for overhead damage?
DrDoc
Next step to pull the valve cover and look for overhead damage?
DrDoc
DrDoc
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Found it! #6 exhaust push rod was out. Noob question, do I have to pull the head, or can I just reinstall?
DrDoc
DrDoc
RiverandSand
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Pull the rod out and inspect it, look at the ends and roll it on a flat surface to see if it's bent. There is a reason it came out, it's not a common occurrence. Check the rocker too.
I would replace both rocker and rod.
I would replace both rocker and rod.
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When you had the air cleaner off looking for a backfire-is this a normal thing or just troubleshooting?
A worn rod seal or incorrect rocker torque can lead to this issue
A worn rod seal or incorrect rocker torque can lead to this issue
DrDoc
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Just troubleshooting. I had just changed oil and air filter a couple weekends ago.
I just ordered rockers, pushrods, and a couple lifters though I'm not sure I'll be able to get them out with the head on but they were cheap so I threw them on the order. Now the week wait for Rock Auto...
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You do need to take the head off to get the lifters out.
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Primary question to answer before you dive into it.....why did the pushrod come loose in the first place? My guess is you have a flattened cam lobe. Would hate to see you repair everything and then just have it happen again after you start it up. Good luck.
DrDoc
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I believe you would install the rod and rocker, hand crank engine to the point that valve should be operating and pressure solid on the rod, then see if sloppy enough to pop out still. Technically it should be "stuck" in there at all points when the lifter is pumped up good...
I may be off base here - not sure if there is a better way. Might be able to measure movement with a dial indicator riding on the cam lobe, or lifter while hand cranking too?
I may be off base here - not sure if there is a better way. Might be able to measure movement with a dial indicator riding on the cam lobe, or lifter while hand cranking too?