P0300 after replacing intake manifold Gaskets

1999 BUICK CENTURY
102,000 MILES
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BCMULLEN95
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I replaced the intake manifold gaskets, 4 exhaust push rods, two rocker arms and now I have multiple misfire and the car runs like crap. I broke the rocker arms and push rods by switching the intake and exhaust push rods unintentionally. Is there a possibility that I could have done other damage that I can not see from just a general inspection. Could I have bent the cam shaft or the valves by putting the push rods in the wrong spot?
Mar 14, 2012 at 12:56 AM
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CADIEMAN
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are they all the same size?
Mar 14, 2012 at 1:16 AM
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CADIEMAN
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cam shafts dont bend they break. it is very poss. if you have done all this damage you have bent a valve.start with a compression test.then come back with reading. you may have to have the head rebuilt and damaged parts replaced.
Mar 14, 2012 at 1:31 AM
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BCMULLEN95
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I am going to check that but I don't that I broke the came, I could see it rotate all the valves when I manually rotated the engine. I am also going to check timing. I was just curious as to what are the possibilities of what could be causing the p0300 code after I did what I did.
Mar 14, 2012 at 4:50 AM
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CADIEMAN
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youll need to do a compression test first!!!!!!!!!!!!!
Mar 14, 2012 at 11:05 PM
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BCMULLEN95
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Compression test is as follows cylinder #1 175 psi, #2 0, #3 0, #4 120 psi, #5 0, #6 155 psi. So as I am to assume that I bent the intake valves on those three cylinders and need to check to make sure the other valves are not bent.
Mar 15, 2012 at 2:28 AM
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CADIEMAN
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youll need to remove the valve covers and check the valve operation on those 0 cylinders.watch the valves on those 3 cyls. to be moving in and out.somthing broke those rockers.if any valves arent moving.you will need to pull the heads and have them checked.it maybe cheaper to buy used heads or a reblilt pair
Mar 15, 2012 at 8:46 PM
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BCMULLEN95
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I bent the valve, replaced the heads and the car runs better nor than before I damaged it.
May 12, 2014 at 1:07 PM