To all the sharp minds. I have a '98 Chev Truck with the Vortec 350. After doing a ton of internet research, I have determined that the lifter noise I hear on start-up when the truck is cold is likely caused by lifter bleed down. The sound goes away after about 1 minute of driving. This appears to be a very common problem with the factory hydraulic roller lifters on the vortec 350's after about 120k miles. I have 170k miles. The roller lifters are generally known to be noisy.
I have 2 questions in this regard:
1. These roller lifters are pretty expensive. A whole set can run close to $500. I'd like to just figure out which one has gone bad, and replace that one. How do I figure this out?
2. With flat-tappet lifters my understanding is that if you replace the lifters, you've got to replace the cam, because new lifters and cams harden/temper themselves on initial run-in. An old cam would chew through new lifters and vice-versa. However, since my lifters are rollered...does this rule apply? I'd rather not buy a new cam-shaft as well.
I'd sure appreciate anyone's input on these points.
Jim
I have 2 questions in this regard:
1. These roller lifters are pretty expensive. A whole set can run close to $500. I'd like to just figure out which one has gone bad, and replace that one. How do I figure this out?
2. With flat-tappet lifters my understanding is that if you replace the lifters, you've got to replace the cam, because new lifters and cams harden/temper themselves on initial run-in. An old cam would chew through new lifters and vice-versa. However, since my lifters are rollered...does this rule apply? I'd rather not buy a new cam-shaft as well.
I'd sure appreciate anyone's input on these points.
Jim