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Carb or piston problems?

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Old Apr 14, 2008 | 09:21 PM
  #1  
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Default Carb or piston problems?

While driving on the interstate, I began hearing popping noises, which didn't sound to me like backfiring, but they could have been. I pulled over and took off the air cleaner to find what appeared to be oil bubbling in the front two openings of the carb (I have a 4 barrel holly with electric choke by the way). I took off the carb and replaced the gaskets underneath, cleaned it out well and put it back together. Tried to start it up and was succesful but would kill after a few seconds. Didn't see any oil in the carb. Opened the oil cap to look for blue smoke (as I was advised by a friend) but saw no smoke of any kind. When the car was revved up to try to keep it running, small flames actually jumped out of the front of the carb.

A friend told me if I have oil leaking into the carb, I could have a bad ring on a piston. Could this be the case here?

Other notables: the car was running fine until today, back and forth between Baton Rouge and New Orleans (about 65 miles) once a week. Timed properly. Fuel/air mixture appeared okay but I did not set it once I put the carb back on, as I couldn't get the car to stay running. Also, I don't know what I'm doing, so any simple suggestions will help.

Thanks for any help
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Old Apr 15, 2008 | 12:10 AM
  #2  
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Originally Posted by spike1360
While driving on the interstate, I began hearing popping noises, which didn't sound to me like backfiring, but they could have been. I pulled over and took off the air cleaner to find what appeared to be oil bubbling in the front two openings of the carb (I have a 4 barrel holly with electric choke by the way). I took off the carb and replaced the gaskets underneath, cleaned it out well and put it back together. Tried to start it up and was succesful but would kill after a few seconds. Didn't see any oil in the carb. Opened the oil cap to look for blue smoke (as I was advised by a friend) but saw no smoke of any kind. When the car was revved up to try to keep it running, small flames actually jumped out of the front of the carb.

A friend told me if I have oil leaking into the carb, I could have a bad ring on a piston. Could this be the case here?

Other notables: the car was running fine until today, back and forth between Baton Rouge and New Orleans (about 65 miles) once a week. Timed properly. Fuel/air mixture appeared okay but I did not set it once I put the carb back on, as I couldn't get the car to stay running. Also, I don't know what I'm doing, so any simple suggestions will help.

Thanks for any help
Do you have a PCV, if so maybe you are pulling in oil from your valve cover up to the base of your air cleaner then in the carb.
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Old Apr 15, 2008 | 12:56 AM
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Yes I do. And I noticed oil on the tip of the connector coming out of the valve cover when I was unhooking the carb now that you mention it. Any ideas what could cause this/ how it could be fixed?
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Old Apr 15, 2008 | 02:37 AM
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Originally Posted by spike1360
Yes I do. And I noticed oil on the tip of the connector coming out of the valve cover when I was unhooking the carb now that you mention it. Any ideas what could cause this/ how it could be fixed?
There should have been some oil in the bottom of your air cleaner base.
The PCV has a ball in it when you pull it out of the valve cover if its not sticking when you shake it you should hear a rattle, thats the ball moving around in it. they are very cheap in cost just go to the auto store buy a new one. clean up any oil in the hose going up to the air cleaner and the base of the air cleaner.

Last edited by Little Mouse; Apr 15, 2008 at 04:03 AM.
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Old Apr 15, 2008 | 03:23 PM
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The first thing I'd do is throw a timing light on it and see where that sits. The holddown may have come loose and the distributor has moved slightly, throwing off the timing. Also a possibility is that the timing chain jumped a tooth, throwing off the cam and ignition timing. I'm assuming you've already checked for vacuum leaks.
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Old Apr 16, 2008 | 12:32 PM
  #6  
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Originally Posted by spike1360
While driving on the interstate, I began hearing popping noises, which didn't sound to me like backfiring, but they could have been. I pulled over and took off the air cleaner to find what appeared to be oil bubbling in the front two openings of the carb (I have a 4 barrel holly with electric choke by the way). I took off the carb and replaced the gaskets underneath, cleaned it out well and put it back together. Tried to start it up and was succesful but would kill after a few seconds. Didn't see any oil in the carb. Opened the oil cap to look for blue smoke (as I was advised by a friend) but saw no smoke of any kind. When the car was revved up to try to keep it running, small flames actually jumped out of the front of the carb.

A friend told me if I have oil leaking into the carb, I could have a bad ring on a piston. Could this be the case here?

Other notables: the car was running fine until today, back and forth between Baton Rouge and New Orleans (about 65 miles) once a week. Timed properly. Fuel/air mixture appeared okay but I did not set it once I put the carb back on, as I couldn't get the car to stay running. Also, I don't know what I'm doing, so any simple suggestions will help.

Thanks for any help
Did you get your car fixed.
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Old Apr 16, 2008 | 12:53 PM
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There should be a baffle in the valve cover under the PCV valve. That is to keep liquid oil from splashing up on the valve and getting sucked into it. If you don't have a baffle there, ingested raw oil is likely your problem. See if you can rig up a baffle [of sorts] out of a scrap of sheet metal epoxied (or pop-riveted) to the cover. If that solves the problem, leave "as is", or go buy a good set of covers with baffles.
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