So I have heard this noise over the past few months. It only occured when I was at about 55 60 mph on the freeway. The noise seemed to be almost like a fluttering. When I would get up to this speed It would start the sound, I let off the gas and ease into the engine would pick up and the flutering would go away and the motor would run smooth. So on my way home tonight the fluttering came back but stayed. The car ran like **** and I barely made it home. I took the backroads and eased her home. Upon further inspection I looked around the motor nothing seemed to be out of place. So I took of my valve cover and I checked my rocker arms and notice that one of the rocker arms was loose and the adjusting nut was loose. So I was throwing this to you guys what should I do about this? What is the cause of this? should I check for a bent pushrod and how do I go about fixing this? When I first got the car it didn't run and some of the pushrods where bent, I bought all new pushrods, adjusted them to spec and it has been running for 5 years great. Now this! Thanks guys!
Check the pushrod if it is OK put it back in and recheck the setting after you have run over a 100 miles if it changes you might try to track down a replacement rocker arm as it could be the adjuster or the rocker arm threads.
If it has been running for 5 years ok then I would think the nut just backed off. The push rods mostly likely got bent because they came out of the center of the lifter and or rocker and got into a tight spot if you know what I mean. Check the pushrods again and replace the nut & rocker arm(if needed). You can also check the engagement between the rocker arm and valve tip at that time. Just take a black marker and color the top of the valve tip. Adjust the rocker and turn the motor over (by hand is fine). Then remove the rocker and check the pattern on the top of the valve. It should look like the picture below. The valve on the left is what I am talking about. If the push rod is too long or short it will move this line closer to the edge of the valve tip which could cause a problem like you experienced.
The Jalopy Journal
