# Bent a pushrod...any ideas?



## taylorjones_11 (Jun 19, 2013)

Hey guys, If you haven't seen any of my write-ups, I have an 04 GTO with a 5.3L Long block. Previous owner swapped the Ls1 for that, not real sure why other than he may have blown up the Ls1. Anyways, I was driving home from work the other night, car felt like it was running great and I goofed off a bit ran it pretty hard. The next day drove the car, didn't notice anything unusual, but sat in traffic for 45 minutes. The car sat all day then I drove it that night and started hearing a loud tick. Almost squeaking at idle, and then sounded like someone tapping on an anvil with a hammer as you revved. I didn't pay much attention to it but as I noticed I could actually hear it while I was cruising down the highway with the windows up. I knew it was a concern now. Listened to various parts of the motor, came up with the assumption it was under the driver valve cover, pulled it and found what appears to be a bent pushrod. Going to pull it out and replace it later this morning when the new one comes in. Any ideas on how I bent it? I don't feel like I overrevved the engine. I ran it up to maybe 5800rpms, but I know I've wrapped it up to 7200 before and never had issues.


----------



## taylorjones_11 (Jun 19, 2013)

Update... I pulled out the pushrod I thought was bent, replaced it. Noise was still there, so I pulled the valve covers again, pulled the pushrod behind the one I replaced, It was bent too. Ended up putting the one I pulled first back into the motor in that other location. Noise is still there and Identical. No clue what it is. Will post a video of the 

http://youtu.be/972KVdt0x7I

Took this video a couple of days ago, It's not the belt drive, I've listened to the valve covers with a long pipe and the noise is very prominent in the back towards the firewall on the valve cover. The other side sounds smooth as glass.


----------



## eeyore (Oct 23, 2014)

Sounds like a worn rod bearing allowing the piston th strike the head or a roller lifter coming apart.

Check pushrods by rolling on a flat surface and check both ends for gaulding.


----------



## taylorjones_11 (Jun 19, 2013)

Pulled two pushrods this morning and they did seem a little bent, but I couldn't tell without rolling it across a flat surface. Also the noise did not change whenever I replaced one. Another thing is this noise popped up out of nowhere at all. No noise, then boom big ticking noise, that would be the only reason I would doubt it would be a worn rod bearing. Something is telling me it might be an intake lifter. No misfire in engine, performance seems normal. It's my daily driver so Driving carefully and listening for changes. Noise is definitely not as profound at 1500-2000rpms as it is at idle, more of a ticking noise after 1500rpms. I will add that the pushrods I pulled were rounded just like the new one, besides color, you couldn't tell the difference just looking at the old and new, the ends look perfect.


----------



## svede1212 (Nov 1, 2005)

Pushrods bend from over revving the engine and getting valve float. If they don't roll perfectly smooth on a pane of glass they are bent. That's why high revving engines should have higher end lifters, pushrods and heavier valve springs. A light weight valve doesn't hurt either. I think it could still be in the valve train and collapsed a lifter. It's probably time to pull the head and slap some new lifters in and get a set of chromemoly push rods.


----------



## taylorjones_11 (Jun 19, 2013)

Thanks for the reply, what style lifters would you suggest? Also from the valve train up isn't a 5.3 the same as an ls1?


----------



## svede1212 (Nov 1, 2005)

Yes they are although the replacement lifters are LS7 now. LS7s or the Caddy race lifters are OK. The "street" link bars are pieces of sh*t and you have to go up to the $600 and up lifters to get the good billet ones. You should measure push rod length with new lifters as they are more than likely a higher seat and some require a different pre-load.


----------



## taylorjones_11 (Jun 19, 2013)

I am looking at pulling the head next weekend. I've never done this before so any input would be greatly appreciated. As far as I've been is pulling the valve covers off and pulling out the pushrods. I need some special instructions for doing this job. I won't be able to pull it all off and put it back in the same day. I won't have the time but most of all I won't have the parts. I'm not planning to order the parts until after I have pulled the bad lifter. What would y'alls suggestion be on pulling this apart. Should I wait until someone with experience can help or is disassembling not a big deal? Can the motor be exposed like that for a couple of weeks, or should I try to cover it with plastic bags, The hood will be closed but I don't have a garage or carport. I'm also under the impression that you cannot reuse the head bolt studs or the gasket. So in this case would it be better to replace all the lifters and upgrade them while I'm in there or just the one bad one? whole set of lifters will take longer for me to order because of the cost which means more time for the car to sit. I just need someone to explain to me what I'm getting myself into

Thanks!


----------



## svede1212 (Nov 1, 2005)

It's fairly straight forward. Yes the gaskets and bolts are "use once". You can get ARP bolts which cost more but are better and can be reused many times. There is a good head write-up at:

LS1Howto.com

It's Corvette but an LS so it's the same. A tip worth repeating is to make sure you get all of the antifreeze out of the bolt holes. Many use rolled up paper towel until dry. Failure to do so can crack the block.I would cover everything with at least a plastic bag or something taped down if it's going to be open. Ask questions if you get stuck and mark or remember what you take apart.


----------



## taylorjones_11 (Jun 19, 2013)

Any ideas what caused this? Cam looks good as far as I can tell from looking through the lifter slot. Cam has some minor scratches on it, but no pitting. Like I said looking from above anyways.


----------



## svede1212 (Nov 1, 2005)

Ya. It probably turned in the plastic lifter tray. Anytime you're in there they should be replaced. It's the reason people go to link bar lifters to eliminate the trays.


----------

