P0300 after replacing intake manifold Gaskets

BCMULLEN95

MEMBER
1999 BUICK CENTURY
102,000 MILES

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?

7 Replies

CADIEMAN

MECHANIC
3,544 POSTS

Are they all the same size?

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Wednesday, March 14th, 2012 AT 1:16 AM

CADIEMAN

MECHANIC
3,544 POSTS

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.

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Wednesday, March 14th, 2012 AT 1:31 AM

BCMULLEN95

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249 POSTS

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.

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Wednesday, March 14th, 2012 AT 4:50 AM

CADIEMAN

MECHANIC
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Youll need to do a compression test first!

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Wednesday, March 14th, 2012 AT 11:05 PM

BCMULLEN95

MEMBER
249 POSTS

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.