Bent pushrod

[TurboShane]

What would cause a pushrod to bend? Put a new pushrod in and it bent it again. Tore off the head and it appears that the valve is ok got to get a spring compressor to make sure. Just wondering if you guys had any ideas?

 

[TurboShane]

Oh ya it's the intake side.

 

[TurboShane]

This is happening to the #1 cylinder on the intake side. Cylinder walls look good, lifter looks good, piston looks good. Valve moves fine right now about an 1/8 of an inch. Have to wait till monday to get a valve compressor to check the valve completly. Car idled and ran fine with the #1 plug wire off. If the valve is not the cause I don't know where to go from there but this happen right after some heavy passes at the track at 26 psi about 2 weeks but I didn't drive much and got worse and worse. I'm thinking the valve guide is toast but that's just me.

 

[TurboShane]

OK, here is the deal I have bent two pushrods now witch never fixed my backfire problem, so I had the motor tore down by my uncle who is a gm mechanic. Here is what we found a blown headgasket between 1 and 3 and a couple other spots, a pushrod that looked like a pretzel. The intake valve on #1 was not bent but was very tight to move. Cam is fine and the lifter is fine. Where do I go from here? The valve stem was scored some and was very tight but did move do you think this could cause the pushrod to bend? Oh and the plastic button was there but looked like it recieved some stress because it was pushed up some was not flat like the rest of them. Thanks

 

[TurboShane]

Any one got any input.

 

[5ltretr]

I had a bent pushrod on #3 , dont remember if it was intake or exhaust, anyway it didnt fix any of my problems just got rid off the ticking sound.

 

[WIKEDV6]

Check the cam lobes, they maybe on the out.

Good luck
Prasad

 

[V6 Beast]

When I started bending pushrods it was due to a worn cam lobe.... I would check out the cam. I could tell from just look at each lifts and seeing how far out of the bore it was coming when rotating engine around.


hth
Sully

 

[S10xGN]

Originally posted by TurboShane
OK, here is the deal I have bent two pushrods now witch never fixed my backfire problem, so I had the motor tore down by my uncle who is a gm mechanic. Here is what we found a blown headgasket between 1 and 3 and a couple other spots, a pushrod that looked like a pretzel. The intake valve on #1 was not bent but was very tight to move. Cam is fine and the lifter is fine. Where do I go from here? The valve stem was scored some and was very tight but did move do you think this could cause the pushrod to bend? Oh and the plastic button was there but looked like it recieved some stress because it was pushed up some was not flat like the rest of them. Thanks

That tight valve could definitely cause a bent pushrod. After it gets good and hot it's likely seizing (hence the score marks). Are you absolutely sure the valve is not bent? Also, check for interference between the pushrod and it's passage in the head. You may be touching at lift and causing a bind. One other thing - if your rocker shafts are on "wrong" (yes, it can be done!) that might be causing your buttons to pop. The 3 through holes are indexed and the shaft only fit correctly one way. It will, however, fit the wrong way if forced. You'd have to notice though, it'd take some serious wrenching to force the bolts in with the holes out of alignment.