will a slightly bent pushrod cause an engine to run rough?
Doesn't seem so. while adjusting the valves I noticed one pushrod had a very very slight bend in it. Hardly noticeable . I adjusted the valves and everything seems pretty good . Is this a problem?
OM314.

It can cause the Engine to run ruff but it depends on how much bend and how much wear in the valve train. An, inconclusive answer.
You could do a Google search for “checking pushrods” and get a more complete info on the issue.
What I was taught is bent pushrods and in the valve train cause the valve clearances to change. Meaning you get it right during the adjustment but if you rotate the engine a few times it may or may not have a difference clearance.
When a push rod is bent it does not have the rigidity it did. And if you notice the push rods usual rotate which keeps the wear in the ball and sockets even.
If the pushrods are tubes with machined ends on them (often silver brazed on). You can drop them on a solid surface and see if the make a ringing noise showing that they are good. If they make a dead sound they are cracked or the brazed ends have issues. (Note on Motor Cycle I had a had one of the push rod ends come off on the Exhaust part of the valve train and when the Piston came up on the exhaust stroke it burned a hole through the piston.)
A way to detect for bent ones is to roll the tube down a flat incline or counter top and see if they roll without wobbling.

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84 300D, 82 Volvo 244Gl Diesel