Valve seems to be moving up and down good,I can see it throught the oil filler,is this an interference engine,possible bent intake valve maybe,or just the injector,,,???
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1998 Buick Century Question: Just replaced a broken pushrod,a long one put on intake,now code 0304 cylinder 4
Answer #1pushrod October 20, 2013, 05:23Master
POSSIBLE: The wrong length pushrod is installed and the valve is not seating properly. Dont think the INTAKE valve is bent while engine is in time, even with the wrong pushrod. The exhaust valve pushrods are longer than the intake but i dont think you can get the two mixed up as it it a good bit of difference, best i can remember. Best way to check this is to remove that pushrod and another intake pushrod then compare the two to see if the one you installed is to long. Any compression on #-4?
Replypjholmes, October 20, 2013, 06:14Rookie
I replaced the broken one,5.99 at advance auto,the short pushrod wasn't even moving the exhaust valve ,got all that fix right and torqued down rockers,pull off plug wire while running,no difference,,the guy had mixed up the 2 pushrods by accident,if I pull 2 plugwires off the coil the fire looks orange
Replypushrod, October 20, 2013, 06:32Master
'ALL' that I can add is the intake pushrod is supposed to be around 5.746" long, that's about 5 3/4" long. Compare that pushrod with another intake pushrod to see if it is the same! Need to check the compression on 4 cyl. first if none or very little, check the pushrod length. IF some how the exhaust p-rod was installed on intake valve, how i cant figure, it is POSSIBLE the valve is now bent, compression test FIRST!!
Dont start looking for another reason for the misfire!!
Replypjholmes, October 20, 2013, 13:14Rookie
Ok,I will recheck those pushrods again,and drag out my big antique sun test and check the comp.,,thanks alot
Replypushrod, October 20, 2013, 13:38Master
Not sure how you mean "thanks alot" lol. You got a Sun? COOL!! Haven't seen one in a few years. Ok, obviously you are not a novice. Let us know what you find!
Borrow a gauge, cause if you are like me, the Sun is all the way in the back, covered up by other stuff!
Replypjholmes, October 20, 2013, 14:30Rookie
I need a different outlook on this,so you advice may be more help than you know
Replypushrod, October 20, 2013, 14:34Master
Well i hope so and glad to help if i can!! Some folks get a little ticked at some of my comments but i am only tryin to help, figure if i put it out ther just how i see it they might get some help out of it. After all this aint my first dance, it's ALL i have ever done and about ready to hang up the wrenches, so it's been awhile! When i TRY to answer a question, it is all from what i have run up on in the many years of actually doing the work. I don't have any Mitchell On Demand or the like here to refer to just to give an answer. Sorry for the rant.