I have a completely stock 1972 472. I noticed the oil flow through the #5 pushrod to the rocker arm is non existent when cold, then a small amount starts flowing when it warms up. Could the restriction be in the lifter itself? Is there a way to unblock it without removing the lifter?
I also noticed the pushrods were spinning rapidly while the engine was running. Is that normal?
Hello Thomas,
The restriction may be due to sludge. Two oil and filter changes within 100 to 500 miles may be all that is needed to clean out the lifter. Additionally, you may find that Marvel Mystery Oil or something similar may help.
The fact that the pushrods are spinning is a good sign. It means the bottom of the lifters are still crowned. This allows them to rotate with each revolution of the respective cam lobe. It also means there is no play between the pushrod seat in the lifter and no play between the pushrod and valve rocker. Change that oil and filter regularly based on mileage and time, as well as driving conditions. When you drive your car, do you get the engine up to normal operating temperature, and keep it there for a while (25 to 50 miles of driving)?
Respectfully submitted,
Christopher Winter
I would pull out the pushrod and make sure it is not clogged before blaming the lifter. I had a couple of completely clogged pushrods on my '74. They are inexpensive items if you need another (Rock Auto has them).
Thank you both very much. I checked the pushrod itself and the passage is clear. I did notice with that valve closed (rocker unloaded) I have some play in the rocker arm. I am able to move it side to side a little bit, and it feels looser than the others. The subject pushrod also doesn’t spin like the others do while the engine is running.
A loose Rocker Arm doesn't sound nice.
Check the Rocker and Stud to see if that is loose, but it also could be a problem with the Lifter, or Cam Lobe.
With the Pushrod not being blocked, then it looks like the Lifter is not getting oil, to allow it to continue up the pushrod
Bruce. >:D
PS. If you can get one of those Video Cameras on the end of a flexible attachment, with the pushrod removed, you will be able to put it down the hole and see if the Lifter top has a problem.
Thomas,
IF you mean a push rod on the #5 cylinder I would check the oil pressure with a gage. That is just about on the end of the "oil trail" and is where shortfalls might show up with a lack of oil pressured.
Greg Surfas
Thanks Greg, it is the #5 cylinder exhaust valve. My next step will be to install a gauge where the factory oil pressure switch is at the back of the engine.
I finally got around to checking the oil pressure. It read 50 psi after startup, then went down to 40 psi once it warmed up. I never saw it go below 38-40 psi. Do you think putting Mystery oil down the pushrod tube would help clear up the lifter?
I would not get my hopes up but it can't really hurt.
The check valve in the lifter will more than likely prevent any oil from going back into the lifter, and may keep it from going down the pushrod too.
If you want to use marvel mystery oil, the best way to get it into the lifter is to add it to the oil in the pan. Just substitute a quart of it for a quart of oil.