Posted: Sun Oct 13, 2013 8:58 pm Post subject: Loud Knocking/Ticking sound when Idle or Under Load
Where do I start...
So I have a 05 Impala that I topswapped to a genV blower and SD headers... About a week ago I started driving with my windows down and music off and i noticed a faint ticking sound coming from the engine area. I didn't pay it much attention at first, however, as the week progressed It lingered in the back of my mind and I kept listening for it. Wednesday or Thursday morning I got in the car started it and attempted to reverse. The car did reverse but it felt like it was sputtering a bit. Anyways, I put it in drive and sputtering went away and drove normal. In the evening I got in the car started it after it being off all day. I realized that the ticking sounds got louder. I had a moment and just drove home. When i got home and was in the parking garage, I guess the closed space amplified the sound more to where It was sounding like a rod knock. I parked, popped the hood up and grabbed my mechanic stethoscope. It was dark so I just left it.
Next day I started the car and it sounded like loud knock sound in the block while idling and while engine under load.
Today, off from work, I decided to use the stethoscope and do some more searching. I turned the car on this morning and got 3 codes. P0122, P306, p0641. So TB sensor low circuit, misfire cylinder 6, and reduced engine power code (according to google). After probing, the knock seem to be the loudest around the rear valve cover cylinder 6.
This lead me to remove the rear valve cover. When I did that I found that the farthest right valve rocker arm had a lot of play between the pushrod and the spring (even though the screw holding the rocker to the head was still torqued). I removed the screw and lifted out the rocker, pushrod and screw to visually inspect. The rod was not bent. .
I then decided to remove the next one over rocker arm,pushrod assembly so i could do a comparison. What I found was that the spring supporting that one was sitting lower when being compared to the first rocker arm that I removed. I also noticed that the pushrod was sitting higher in this one when being compared to the pushrod in the first rocker arm removed. So basically, pushrod on the problem rocker was sitting lower than all other pushrods on the rear head and its associated spring was sitting higher than all other springs on the rear head. Example video ------> http://www.youtube.com/watch?v=uNWhIjA9c6A
I have been scratching my head at this all day. Could it be a stuck lifter, or......?
SuperCharged 9c1 | Tuned | SD Headers
Next time you get pulled over and you know you have illegal tint Follow these instructions: Tie a string around your power window fuse, and after you roll down your drivers window yank the fuse, which will render your windows inoperable. They can't test the film if the meter can't fit over it.
It could be a collapsed lifter, or possibly the other thought that came to mind would be a broken valve spring. Usually a half a quart of trans fluid in the oil will make the lifter pump up. Sound goes away...new lifters.
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