Shudder under load in lockup
#21
#22
The holes in the GP for the rocker studs are slightly too large causing them to turn out a little when the studs are tightened. Plus the underneath side of the plate is a sharp 90* angle, not rounded like the top edge, acts like a cutting tool on the pushrods. And they make a lot of valve chatter. Definitely something that needs to be resolved.
#23
#25
#26
The procedure I used for adjusting was when exhaust valve begins to open I adjusted the intake rocker, when the intake valve begins to close I adjusted the exhaust rocker. I used 5/8th turn pre-load.
Going to try a new method this time. As soon as intake valve closes going to rotate crank using breaker bar from 12oclock to 5oclock and adjust both rockers together. Going to use 1 full turn preload.
#27
Could try doing a 'running adjustment'.... though, it has the potential to be messy..... I had a spare set of valve covers I cut the tops off, so oil would be contained, but, I could still get at the adjusters. This only works with the adjuster being the rocker stud nut though, is that the way yours are? Or, are your adjuster on the pushrod end of the rocker?
#28
Could try doing a 'running adjustment'.... though, it has the potential to be messy..... I had a spare set of valve covers I cut the tops off, so oil would be contained, but, I could still get at the adjusters. This only works with the adjuster being the rocker stud nut though, is that the way yours are? Or, are your adjuster on the pushrod end of the rocker?
Did a cylinder leak down test today. Seems too good to be true for a motor with 180,000 miles, but only have 3 to 4% leakage across the board according to my Harbor Freight leak down tester, all passing thru the rings. I suspect the gauge is not accurate and could have leakage closer to 10%, but the good news is that it shows even leakage readings and the valve train is not leaking at all.
Didn't get to removal of the valve train today, probly get to it this week some time.
I also bought a mechanical oil pressure tester. How do I remove the oil pressure sensor? Will a deep socket fit over it? it's pretty tight back there to fit a wrench.
#29
#30
Got the oil pressure sensor out. Used a short handled 1 1/16inch open end wrench.
Tested oil pressure with a mechanical gauge. Pressure is good, my Melling HV72 is providing 27psi at idle and 55psi just off idle, and revving brings it up to 65psi.
Replaced the oil sensor with dealer part for $83. My old sensor kept the guage pretty steady at 40psi and occasionally read 50psi, hardly ever saw the needle move.
The new sensor has the guage reading 30psi at idle and almost instantly moves when tapping the gas, between 45 and 60psi. Much more accurate.
I saw some spark jumping from my new Napa wires the other night so think that could possibly be the problem with the random misfire. Decided to get the Davis Ignition kit with 10mm wires, matching red cap, rotor, and new high amp coil.
It's a little expensive $230.
When I did the power balance test there was very little difference in idle when unplugging the injectors. RPM may have dropped 25rpms. Still going to drop off my injectors for testing. So far the Lucas fuel system cleaner hasn't helped.
I adjusted and properly installed the guide plates, rockers and pushrods.
The guide plates were upside down, not sure it matters much. Filed the sharp edges off the GPs and torqued em down without them moving.
The rockers were very loose to the touch, I didn't use the proper method of backing off the wrench and then retightening while holding the polylock. I used 1 full turn preload.
The pushrods hadn't gotten any further wear from the last time I had checked them but I inverted them anyways to have the unworn end in the GPs.
The valve train ticking under the hood is nearly gone now. It's very quiet, I think it will quiet down further after the GPs wear into the pushrods with the appropriate light contact.
Getting parts and services will be slow so I can spread out the expense over a few weeks.
Tested oil pressure with a mechanical gauge. Pressure is good, my Melling HV72 is providing 27psi at idle and 55psi just off idle, and revving brings it up to 65psi.
Replaced the oil sensor with dealer part for $83. My old sensor kept the guage pretty steady at 40psi and occasionally read 50psi, hardly ever saw the needle move.
The new sensor has the guage reading 30psi at idle and almost instantly moves when tapping the gas, between 45 and 60psi. Much more accurate.
I saw some spark jumping from my new Napa wires the other night so think that could possibly be the problem with the random misfire. Decided to get the Davis Ignition kit with 10mm wires, matching red cap, rotor, and new high amp coil.
It's a little expensive $230.
When I did the power balance test there was very little difference in idle when unplugging the injectors. RPM may have dropped 25rpms. Still going to drop off my injectors for testing. So far the Lucas fuel system cleaner hasn't helped.
I adjusted and properly installed the guide plates, rockers and pushrods.
The guide plates were upside down, not sure it matters much. Filed the sharp edges off the GPs and torqued em down without them moving.
The rockers were very loose to the touch, I didn't use the proper method of backing off the wrench and then retightening while holding the polylock. I used 1 full turn preload.
The pushrods hadn't gotten any further wear from the last time I had checked them but I inverted them anyways to have the unworn end in the GPs.
The valve train ticking under the hood is nearly gone now. It's very quiet, I think it will quiet down further after the GPs wear into the pushrods with the appropriate light contact.
Getting parts and services will be slow so I can spread out the expense over a few weeks.
Last edited by beeker; 02-20-2015 at 07:32 PM.