poping sound at full throttle

Old Aug 12, 2012 | 06:17 AM
  #1  
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Wink poping sound at full throttle

I bought a 72 cutlass with a 350 motor. Well at full throttle I have a poping sound, Seems it's coming from one cylinder. It runs fine other than that it doesn't miss at normal acceleration. Seems the sound does come from or threw the carburetor. Just wondering if I should be concerned about this.
Thanks Barb.
Old Aug 12, 2012 | 07:32 AM
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Culd be an intake valve not seating properly. I had this problem with a SBC after installing an MSD. With the hotter spark the problem reared its ugly head. I ended up redoing the motor. The valve had receded into the head because of the no lead in the gas thing. It took a very long time but it happened. If you have a high mileage motor and you haven't been adding a lead substitute, this may be your problem. A leak down test would prove it out.
Old Aug 12, 2012 | 08:03 AM
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OH Boy! That's not what I wanted to hear, but the truth hurts sometimes.
The engine was rebuilt sometime before my purchase. Sounds like they put a not stock cam in. It has headers and a holly intake. I would hope or think they would have upgraded the heads, but you never know. Well thanks anyway. Barb.
Old Aug 12, 2012 | 09:16 AM
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Try a fresh set spark plugs before you do too much else.
A compression check would also be a good place to start.
Old Aug 12, 2012 | 09:45 AM
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I put new spark plugs in about 300 miles ago. I think I'll get that compression check and go from there. This car has been one big pain in the .
Thanks again Barb.
Old Aug 12, 2012 | 09:52 AM
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Check for a flat lobed cam on the exhaust valve. Lots of new cams having that issue over the last few years.
Old Aug 12, 2012 | 09:57 AM
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Also when was the last time you changed the wires, cap, and rotor?
Old Aug 12, 2012 | 10:14 AM
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Could be a bad wire, cap or rotor, too.
Or even a bad valve spring, bent pushrod or worn rocker arm.
Also bad valve guide or seal.
Plugs will misfire with contamination.
Look for a discolored plug, and concentrate on that cylinder.
Old Aug 12, 2012 | 12:20 PM
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The plugs look good and the distributor was upgraded. I think a compression check is the first thing on my list of things to do. I just hope I don't have to tear into the engine to much. Just bought this car in January and it's been one thing after another, Well no more old cars. I'll go buy a new Camaro next. Barb.
Old Aug 12, 2012 | 12:40 PM
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Don't give up - it could be minor!
As much as I like the Camaro's, they're 'belly button' cars - everyone has one!
Old Aug 12, 2012 | 02:16 PM
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I know, It's just that I thought I bought a good car and I've had nothing but problems.
Oh well, I'm sure I'm not the first one to be taken. Just have to fix what needs "fixen" and move on. Thanks Barb.
Old Aug 12, 2012 | 03:12 PM
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Half the fun of owning a classic car is getting to know it, and it's idiosyncracies.
Have a friend who had bought a new 'vette, and during it's first oil change, began singing 'getting to know you'! My brother nearly fell down , laughing.
I know having a DD that's constantly giving you problems is a real PIA, but as you fix it, and upgrade it your way, you get a feeling of achievement.
Unlike the sinking feeling when you drive a new car out of the dealership, and you know the first block cost you 3-5 Grand!
Not to mention car payments and insurance rates on a 'sports car'!
Old Aug 12, 2012 | 05:46 PM
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The biggest problem being an old car owner, you have to be an old car maintainer. These cars can and probably will nickle and dime you to death for the length of ownership. On the brightside, there is no other feeling like owning and driving them. I drive mine everyday, when I get off work after a bad day, I can start it up and throw it in gear and it seems all the weight of the world is lifted off my shoulders!!
Old Aug 12, 2012 | 06:48 PM
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Thanks alot for all the support, and I know you're all right. I bought the car on the first sight love affair which is allways the first mistake. I'll do whatever it takes to make it right, I could never sell it knowing it has problems. I AM A OLDS FAN, I love Cutlass.
Barb.
Old Aug 12, 2012 | 06:53 PM
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Well, since you can't buy new - - - - - -
Old Aug 12, 2012 | 07:03 PM
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Oh! What, " Thanks Barb".
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