[25stevem]

Pull all the plugs out and spin the motor over with the starter.

If the noise shows up then jack the nose of the car up enough to get under it and then have someone crank the starter and then see if you can pin down where it’s coming from.

Also take a good look at the oil pan in case you pushed it in with jack when working on the cam swap.

[mgarblik]

Originally Posted by chiphead

Sorry for video quality, its all I had at the time. I cant say there was no noise before the cam change. I've basically had 10-15 minutes runtime with this engine prior to cam change, and it never idled below 1000 prior to the cam change. I just bought this car and I know nothing about the engine. The PO was evasive when I asked anything about the engine. So there were already red flags that the engine had issues, and I priced that into my offer.

When I had the cam out, I noticed some slight clanking when I turned the engine rapidly back-and-forth with a breaker bar. I looked down at the crank and rods through the valley and didn't see anything wrong. I should have dug further at that time, but I was so invested in the cam change I wanted to get that done first. I admit this is a failure in my diagnostic effort since I heard a noise while turning it over by hand. It sounded like it was coming from the back or behind the engine.

Right now I'm hoping it's a broken flexplate or a trans issue. I'll dig into it and report back. How safe is it to disconnect and push the converter back and run the engine by itself?

Yes I tend to agree with you and others about flexplate/torque converter in light of the additional information. Unbolt the converter and push it back and start engine. 10 minutes to learn allot.

[Formulas]

if the converter is loose putting a breaker bar on the balancer bolt totating the engine back and forth may create the noise

Which brings to mind you did properly torque the balancer bolt on front end install??

[geeteeohguy]

What these gents said. I hear the noisy alternator more than anything. I would remove the belts and run it again. Could very well be a loose converter bolt or balancer bolt. I don't hear anything that sounds like a bearing knock or piston slap.

[1969GiPper]

Originally Posted by geeteeohguy

What these gents said. I hear the noisy alternator more than anything. I would remove the belts and run it again. Could very well be a loose converter bolt or balancer bolt. I don't hear anything that sounds like a bearing knock or piston slap.

Before removing all the belts get a spray bottle of Windex (glass cleaner) and with the engine running at idle spray each belt with the Windex. Spray it generously at each belt on the side riding in the pulley groove. If the noise goes away buy new belts. Note: the Windex will only stop the noise till it drys out. So the noise may return. Do not use belt dressing. Before installing new belts clean all the pulley grooves completely. Be careful of the moving belts, pulleys and fan blades.

[NeighborsComplaint]

Originally Posted by mgarblik

Yes I tend to agree with you and others about flexplate/torque converter in light of the additional information. Unbolt the converter and push it back and start engine. 10 minutes to learn allot.

I drove to a local car show years back with no issues. Then I got in the registration line where you sat and crept forward for registration and insurance checks. I'm 10 cars back with tons of people walking past the cars and admiring them when mine began making sounds like a roto-tiller chewing through rocks in the garden. Nice entrance that was with people pointing at your car and giving you the palms-up "what's wrong with your car?" hand signs and offering to help you push it to the side. I had no inspection plate on it at that time so I found a grassy place to park and took a wrench to it. I found all the convertor bolts just hanging by a thread or two. fortunately none of the holes wore out of round.

[Schurkey]

Originally Posted by 1969GiPper

Before removing all the belts get a spray bottle of Windex (glass cleaner) and with the engine running at idle spray each belt with the Windex.

Plain water in a squirt bottle works just as well for diagnosis, and doesn't leave any residue.

[Vid]

Lots of good advice here so I can’t add much. I’ve had the fan hitting shroud issue and it started after the motor warmed up. It was an aftermarket shroud made from the wrong type of plastic and it got so soft when it warmed up it literally got sucked into the fan blades. But that doesn’t sound like the problem you have. Sounds like the best place to start is all the bolts on the front pulleys and the converter. They’re easier to overlook than we imagine. Hopefully you’ll find the problem and won’t have to remove the timing cover. If you don’t find loose bolts fore or aft, I’d go with popping both valve covers next. Good luck and keep us posted.


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[68WarDog]

" I just bought this car and I know nothing about the engine. The PO was evasive when I asked anything about the engine. So there were already red flags that the engine had issues, and I priced that into my offer".



With just that information, I wouldn't drive the car any further until pulling the engine for a complete diagnostic. It could be something simple or something serious the po didnt divulge. Do you want to take a chance on completely destroying your engine?

[turbo69bird]

Gonna definitely need to do some testing to find it but those are items to check that could save a lot of back breaking work, I’d also pull the valve covers look for anything w the rockers. Though I think that would be consistent . The fact that this goes away with RPM is interesting .

One posters thought on a fan blade hitting a shroud could be that way . Flex blade flattens out w RPM . I’d start there and flex plate issues including a cracked flex plate all the way around the bolts which I’ve also seen.

[Joe's Garage]

Why did you change the camshaft ?

To upgrade for better performance or to repair a wiped cam or ???

I'd be checking to see if the cam retaining plate and fuel pump eccentric got reinstalled correctly - mostly the cam retaining plate. That will require the timing cover coming off again, but it's only a couple hours and another gasket to do that.

If that retaining plate is missing, the cam can walk forward and back and the lifters can potentially hit the wrong lobes and it just basically makes a big mess.

A good friend who mainly messed around with Chebbies left his retaining plate off his 1970 Trans Am many moons ago - back in the early 80s - and it chunked the cam lobes up pretty good. I don't recall whether it was making loud noises or not, but the exhaust was pretty loud already.

I'm hoping for your sake it's just loose bolts somewhere. Anywhere.

As others have mentioned, DON'T run it until you figure out what's wrong.

Good luck!

[dataway]

And whatever you do ... POST WHAT YOU FIND

I hate it when a thread like this disappears with no resolution.

[chiphead]

Got the car up on jackstands today.

IF THE CONVERTER'S KNOCKING, DON'T GO ROCKING.

Whoever said loose converter gets the prize. Yup, the converter is loose on the flexplate! Check out the video below. One of the flexplate holes is elongated and the threads in one of the converter mounting feet are boogered up. Check out the mounting bolt from that hole.

I'll have to take a closer look at the flexplate itself to see if there's damage beyond that one bolt hole. What should I look for, it's hard to see in front of the converter?

Onward, party people! I'm just happy it's not in the engine.

https://youtu.be/wPabvV0lCVE

[Murf]

Glad you found it! Did you not drive the car before swapping the cam? I was under the impression it was a new noise& also I was wrong. See I can say it! I’ve had lots of practice . ��

Murf

[dataway]

Of course now you've got me trying to remember if I used locktite on my converter bolts.

[ScumOne]

I had this problem in my 400 before being rebuilt. It was a sticky lifter. I put a quart of Rislone in the motor and the lifter returned to normal.

The other possibility is a rocker arm didn't get torqued correctly and you have one or two loose ones. I'd start with those things and pull the valve covers if the Rislone doesn't fix it.

[PunchT37]

Originally Posted by chiphead

Got the car up on jackstands today.

IF THE CONVERTER'S KNOCKING, DON'T GO ROCKING.

Whoever said loose converter gets the prize. Yup, the converter is loose on the flexplate! Check out the video below. One of the flexplate holes is elongated and the threads in one of the converter mounting feet are boogered up. Check out the mounting bolt from that hole.

I'll have to take a closer look at the flexplate itself to see if there's damage beyond that one bolt hole. What should I look for, it's hard to see in front of the converter?

Onward, party people! I'm just happy it's not in the engine.

https://youtu.be/wPabvV0lCVE

What do we win?

[Vid]

Originally Posted by chiphead

Got the car up on jackstands today.

IF THE CONVERTER'S KNOCKING, DON'T GO ROCKING.

Whoever said loose converter gets the prize. Yup, the converter is loose on the flexplate! Check out the video below. One of the flexplate holes is elongated and the threads in one of the converter mounting feet are boogered up. Check out the mounting bolt from that hole.

I'll have to take a closer look at the flexplate itself to see if there's damage beyond that one bolt hole. What should I look for, it's hard to see in front of the converter?

Onward, party people! I'm just happy it's not in the engine.

https://youtu.be/wPabvV0lCVE

Yay! That is about as happy an ending as we could hope for. Turbo69bird nailed the problem. So glad you found the issue, and shared the details.


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[Dragncar]

Originally Posted by dataway

Of course now you've got me trying to remember if I used locktite on my converter bolts.

I use red Locktight on the bolt AND a jam nut on the other side with Locktight on it also.

[MatthewKlein]

I'm curious what alternator you are running. Looks like a nice upgrade