How to check for bent pushrods in an old engine
Finding bent pushrods in an engine that has sat for decades usually points to a seized valvetrain and deep internal damage. Based on how the engine runs and the condition of the valvetrain, this typically means the motor needs a full rebuild rather than a simple top-end fix.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1dropping in replacement pushrods to see what happens
- 2keeping them running if they are not bent too badly without pulling the engine down
- 3tapping the valve stem with a hammer to test springiness
- 4spinning the engine by hand after adding new oil
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I have a 59 Chevrolet Apache that belonged to my grandfather. It’s been parked since the early 90s and I think I found out why. I rotated the engine before I did anything and it turned like it should, so I believe the two pushrods were bent before I messed with it.”source ↗
“I found them when I started it. It clattered like hell but ran ok considering it was running on 4 cylinders so I don’t think the timing has jumped.”source ↗
“Looks to me that you got a seized up valvetrain.”source ↗
“Full rebuild or new motor.”source ↗
“Its "gotta all come apart" bad.”source ↗
“Thats a rebuild. For more reasons than the pushrods.”source ↗
Where this came up
People with this problem also raised
- 7Why is my engine pulley wobbling and making a grinding noise?
- 12Did my timing belt slip or did I mess up the install?
- 5Engine still squeaking after replacing water pump and tensioner
- 63Why does my car make a loud rattle when starting the engine?
- 3Cracked engine head while torquing oil pressure sensor
- 2How to tell if an engine has blow by