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#1
09-10-2006, 01:28 AM
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Need Some Help, Engine Noise
Hi everybody, I am looking for a little help with my Lemans. Just recently after backing the car out of the garage I noticed a "ticking" noise coming from what seems to be the drivers side of the engine. At first I was thinking that maybe it was an exhaust leak or bad spark plug wires, but when I tap the gas it backfires through the carb. Does anybody know what might be causing this? I am hoping for something easy but I have the horrible feeling that it is a sticking valve, dropped lifter, or something along those lines. Up until this point it has always ran great. Here are the engine specs:
'72 400, '70 #13 Heads, Stock Exhaust, HEI Ignition, Stock 4bbl Carb. Any help or suggestions on where I should start would be much appreciated. Thanks,
__________________
Nathan 72 Luxury Lemans "I see", the blind man said peeing into the wind, "it all comes back to me now." "every time i learn somthing new it pushes some old stuff out of my brain." |
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#2
09-10-2006, 01:33 AM
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I hope it's not a worn cam lobe
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#3
09-10-2006, 01:47 AM
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If it is what the best way to start checking? I am thinking that I am going to have to start by taking off the valve cover and see how all my push rods, rockers, and valve are moving.
__________________
Nathan 72 Luxury Lemans "I see", the blind man said peeing into the wind, "it all comes back to me now." "every time i learn somthing new it pushes some old stuff out of my brain." |
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#4
09-10-2006, 05:39 AM
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Nathan, see my reply to this question on the mail list.
Use a piece of hose as a stethescope to determine where the noise is coming from. 5/8" heater hose that's about 3' long, or any similar tubing/hose works amazingly well.
__________________
---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
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#5
09-10-2006, 05:44 AM
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When was the last change of oil and filter.....
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#6
09-10-2006, 08:22 AM
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This spring when I took it out of storage. I've only put about 500 miles on it since then. Just out of curiosity what would that have to do with the noise?
__________________
Nathan 72 Luxury Lemans "I see", the blind man said peeing into the wind, "it all comes back to me now." "every time i learn somthing new it pushes some old stuff out of my brain." |
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#7
09-10-2006, 09:34 AM
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I always put a pint of Marvel Mystery oil in the crankcase at oil change time, to keep the lifters from ticking.
Charles |
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#8
09-10-2006, 10:10 AM
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Loose Rocker
Well I just pulled the drivers side valve cover and the rocker arm on the cylinder #3 exhaust valve is shifted off to the side pushing on the spring instead of the valve. Now that I know what the problem is, what do I need to do to prevent this from happening again? I also think that it would be a good idea to check the passenger side.
__________________
Nathan 72 Luxury Lemans "I see", the blind man said peeing into the wind, "it all comes back to me now." "every time i learn somthing new it pushes some old stuff out of my brain." |
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#9
09-10-2006, 10:51 AM
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did the nut come loose or did the rocker just shift off?
__________________
70 GTO 462 E-Heads TKO-600 9-Inch/3.60's |
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#10
09-10-2006, 12:23 PM
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Do the 13's have screw-in studs? Press-in can pull slightly out after some time. Higher lift cam in the previous engine life? Had that problem years ago with a 389.
__________________
CT Gross---66 GTO "Its never too late to have a happy childhood"! I told my dad I was going to stop raising hell, and he called me a quitter! |
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#11
09-10-2006, 08:57 PM
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#13s are big-valve screw-in stud heads.
There is a reason that rocker came off. You need to find that reason and address it before you drive it any more.
__________________
---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
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#12
09-10-2006, 10:19 PM
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That's going to be my mission over the next few days. I figure that I am going to start with pulling the push rod and rocker and taking a good long look at them as well as the nut to see what happened.
__________________
Nathan 72 Luxury Lemans "I see", the blind man said peeing into the wind, "it all comes back to me now." "every time i learn somthing new it pushes some old stuff out of my brain." |
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