Terrible news when I pulled valve cover

[Yukon Jack]

After getting exhaust on the truck the motor had noise that sounded like a couple rockers needed to be adjusted. I pulled the passenger side valve cover and my eyes were met with the sight of three rocker arms sideways. The second pushrod from the rear of the engine is bent up top a bit and must be bent very badly below as I can't pull it out. The other two pushrods where the rockers were off came out straight. I didn't even have the heart to pull the driver side valve cover.


What a terrible let down after being so close to the end. I guess the passenger side head must come off to get that pushrod out and see what damage is done.

Am I correct that I am going to most likely looking at serious engine damage?

[krue]

I don't know what you're gonna find, but that SUX!
I hate it for ya.

[VetteVet]

It sounds like the number 8 intake hit the piston to bend the pushrod that much. The other two might have been adjusted too loosely or the lifters are collapsed.I wonder if the timing chain has jumped a tooth or two. Was the engine running badly before you pulled the valve cover . It must have been because at least two cylinders weren't firing. If you can't get the pushrod out then you should pull the intake off and then you can see what's holding it in. You will have to pull a compression check to see if you bent the valve and you might as well pull the left valve cover to see whats going on there.

[cduster]

Maybe you could get the pushrod out by taking the intake off and cutting it. I wouldn't pull the head unless I absolutely had to. Then you could throw it back together to make an accurate assessment of the situation. Could be nothing major wrong (hopefully) requiring head removal. I am an optimist. The glass is half full.

Dan

[BobbyK]

That sucks man!

[chevyhouse]

I had a similar accident with my 383, not sure what happened but I had about the same situation and survived ok. The worst thing you may be looking at is a rubbed cam lobe, you can bend a pushrod with something as simple as a backfire or maybe you forgot to set them in the hurry to get it running??? replace the bent ones and run it with the valve covers off to make sure you have lift everywhere, you should be fine

[69 Short Fleet]

Yukon, man thats a tough setback. I've been following your progress posts and admire all the work you have been doing. I think I'd pull the intake also, I hope your luck gets better. Doug

[dwaite72lnghrn]

Pull the intake and check the cam if it is a big block. And if the cam doesn't look worn replace the push rods and run a compression test on the bad cylinders. If valves hit the pistons the exhaust valves would be bent first. If all of the water is drained you can compression test with the intake off, Pull all of the plugs and test them all. It will crank faster with all of the plugs out, This will save you gaskets and time if something is bent. Don't let it take the wind out of your sails you are still close. Good luck.

[70c10]

Sorry to hear that. Maybe a board member in your area could stop by and give you a hand figuring it out. It might not be as bad as you think.

[mrein3]

Apples and oranges but I'll relate a story to keep your hopes up...

In approximately 1989 I had my 72 Chevelle up grouse hunting north of Duluth. About 1/2 way through the weekend my fairly new at that time 350 started ticking pretty good on one side of the engine. I drove it the rest of the weekend then all the way home to the Twin Cities.

When I got home I pulled the valve cover off of that side. One rocker arm was broken and that push rod was bent. I found a new rocker and push rod, put it all back together, and to this day haven't done anything to that engine except change oil.

[GSFMECH]

I have had this happen a lot with big blocks when they are equiped with 5/16 pushrods, they are pretty whimpy. They were probably adjusted loosely when you fired it up and the rocker walked around and bent the pushrods. I have even had them punch through the rocker arm. Chances are real good that nothing is hurt but the pushrod. Check the rockers real good.I would do as mentioned above, replace all the bent parts and run a compresion check. I would try and pull that bent pushrod out, and if you can't hopefully all you have to do is to pull the intake to get the pushrod out and be sure the lifter is still in place. You can see the cam lobe from there but it is probaby ok.
Mike

[HuggerCST]

Originally Posted by GSFMECH

I have had this happen a lot with big blocks when they are equiped with 5/16 pushrods, they are pretty whimpy. They were probably adjusted loosely when you fired it up and the rocker walked around and bent the pushrods. I have even had them punch through the rocker arm. Chances are real good that nothing is hurt but the pushrod. Check the rockers real good.I would do as mentioned above, replace all the bent parts and run a compresion check. I would try and pull that bent pushrod out, and if you can't hopefully all you have to do is to pull the intake to get the pushrod out and be sure the lifter is still in place. You can see the cam lobe from there but it is probaby ok.
Mike

^^^^^^^Yea, what he said!^^^^^^^^
Sorry to hear that, but don't let it get you down. Like Mike said, it's not uncommon with big blocks.

[Bram]

Oh man Yukon that really sucks!
Hey don't give up though you'll git-r-done.

Another thing to check is the end of the valve. It could be off-square causing the rocker to rock sideways. To check for this you're going to need to run the engine with the cover off and use a long handled screwdriver to listen; don't drop the screwdriver into the fan like I did.

[knsmodels]

Originally Posted by GSFMECH

I have had this happen a lot with big blocks when they are equiped with 5/16 pushrods, they are pretty whimpy. They were probably adjusted loosely when you fired it up and the rocker walked around and bent the pushrods. I have even had them punch through the rocker arm. Chances are real good that nothing is hurt but the pushrod. Check the rockers real good.I would do as mentioned above, replace all the bent parts and run a compresion check. I would try and pull that bent pushrod out, and if you can't hopefully all you have to do is to pull the intake to get the pushrod out and be sure the lifter is still in place. You can see the cam lobe from there but it is probaby ok.
Mike

I have a Chevelle with a BBC and when I was running stock valve train I use to pop or break rockers all the time.....just driveing along and she would start popping through the carb or exhaust and I would know what the problem was right away....pull the valve cover fix what was amiss and be on my way again....hope it works out....Paul K

[72gord]

Bummer Yukon, keep working at it...hopefuly just bent pushrods. Was that motor used, new, rebuilt? Just wondering. Good Luck, Gord

[jtminton]

My truck had 4 of the rockers turn sideways like that after I got it running again. I had to get a brass chisel and hammer the studs back into the block a little bit. Tightened everything back up and it runs fine now. Still have no idea why it did that.

[Yukon Jack]

Well, I am sure glad to see the responses here. I will keep my fingers crossed and hope for the best!

To answer the questions asked, the vehicle has been ran and driven very little as it has just become somewhat road worthy. When I took a buddy for a ride around the block on Saturday with open headers it was running fine until you got to about 2,000 rpm and stepped on the gas harder, it would just fall on it's face and had no power. It was backfiring or missing with anything over 2,000 to 2,500 rpm. Thinking back I think I heard the pushrod bend. We were turning at a corner and I heard an odd noise and I just assumed it was something steering related - now I'm about certain that noise was the pushrod.

Chevyhouse, a buddy helped with the assembly of the engine and we took our time as the engine was going to sit for quite some time so there was no hurry trying to get it done to fire up and drive. The engine did sit for quite a while after being assembled.

The engine is a 1989 454 with about 120,000 on it. We changed the intake, cam, lifters, springs, and added Comp Cams Magnum rocker arms and went from TBI back to a carb. We inspected the stock push rods and they appeared fine.

Hopefully I can get out tonight and try to get the push rod coaxed out. Then go from there. If I have to pull the intake, well, good time to get it cleaned up a little as it got rained on once when it was at the body shop.

Thanks for all the tips and info, this really helps a novice like me!!!

[Yukon Jack]

Gsfmech - I checked and my pushrods are 3/8", not 5/16".

[dubie]

I had this same thing happen to me Mark. I removed the intake to find 3 bent pushrods. Once the intake is off and the rocker arm is lossened off, the pushrods should come out with a little force. I had every little thing go wrong with my engine upon start up bud so I know where you're coming from. It is a set back but only takes an hour to correct. Mine was caused by incorrect valve adjustment which I'm guessing is the same as what happened with yours. Choke it down, forget about it and get er fixed. I just kept thinking, "I've put to much time and money into this thing and I'm not gonna let this little hang up get me down" Keep pluggin away bud and you'll have er done and cruisin in no time. Just a minor set back! don't get discouraged there big guy

[StingRay]

Man can I sympathise with how you feel. I had a couple of rockers back off during run in on a freshly built small block that I spent literally months assembling and detailing. There is no way I missed adjusting them. Coincidentally I put roller tipped Comp Cams rockers in as well. Perhaps their locking nuts are not what they could be. I was horrified when I heard the jangling sound coming from under the rocker cover when we idled it down from it's 2500 rpm run in. There was no indication of a problem at rpm. I was sick at the thought I might have ruined the cam and spread scrap metal through a brand new motor. After some invesigation I determined that I still had cam lobes and the chances were good that no damage had been done. I checked the push rods for straightness and readjusted the whole valve train. I used loctite on the two nuts that had backed off and all has been fine since. The truck runs very stong and is smooth and quiet. I have about 300 miles of sustained 3000 + rpm highway usage on it so if anything was wrong I would know it by now. I hope your luck is as good as mine was. I actually feel a little better now after reading this thread as I know I am not alone in having this problem.

[GSFMECH]

You are lucky to have the 3/8" pushrods, they are a little stronger. I have bent them though (stock pushrods). The 5/16" are notorious for bending especially if you you put any kind of bigger cam in it. When I was drag racing any time I used a roller cam I would run chrome moly pushrods. In the old days when I was running a flat tappet I had a set of 7/16" pushrods, I have never bent one of them. With the roller lifters the 7/16" pushrods would not clear the lifter crossbar so you had to run a seriously stout 3/8" pushrod. The last BB I raced I had a cam with about .735 lift and I think the seat pressure on the valve springs (triples) was somewhere around 225 closed and I never hurt a chrome moly 3/8" pushrod. I'm building a 454 for my truck right now and have a mild hydraulic cam and am going to try using stock 3/8" pushrods. One thing for sure though if you keep having problems buy a set of high quality chrome moly pushrods from any of the cam manufacturers and you won't have any more problems. I figure once you get this fixed and everything adjusted and she settles in you won't have any more troubles running those stock pushrods.

Mike

[Yukon Jack]

I'm in much better spirits today Dubie after seeing that it is likely that no real damage is done. Just had no idea last night so I was pretty bummed. I can't wait to get off from work so I can run and get some new pushrods and try to get that rod out. This certainly explains why the motor felt like it had no power.

Stingray, it is reassuring to read of this happening to others, cause I just couldn't figure out what caused it. Guess this is one reason experienced motor builders recommend having exhaust on an engine when firing it up - so you can hear potential problems.

[Crazy-J]

I just had almost the same thing happen with my truck last night. Sounded like a stuck lifter but it was fine on the way home other than the ticking noise. Then it started dieing everytime I came to a stop and it was idleing. Drove the last few miles home with it dieing at every stop (had to refire it and then keep my foot on the gas to keep it running) and it a real loss in power. Now it runs rough and lacks any power. Parked it for now and going to check it this weekend. I think I might have a similar problem to yours. I hope anyway so I can fix it!

[john]

One other thing, A friend bent several pushrods and his after market pushrod guide plates were too tight causing the prob. Good luck. I too have been waiting to see it on the road. John

[Sillyoldman]

Be sure to buy new crushed nuts for your rocker arms!

I have had this happen too. No damage to engine. These things loosen up pretty fast when they start to get worn. Especially when you get on it hard.