Hi there I have been experience a loud chatter/clacking noise.
Now first thought was header gasket so checked and changed first thing, no change.
Second thought was lifter/valvetrain noise, everything is pumping lifters have no wear or tear.
Now I am stumped oil pressure is good 40-45psi idle, 60psi riding.
I am using 10w-40 oil. The noise is very loud and I've been adjusting the timing still no avai.
Please if anyone can help I'd be so grateful as this takes away from my cars enjoyment so much. Also I have very good compression very good. Engine temp is perfect all other aspects are up to par so having trouble diagonising the issue..

- much love babafats.

 

Did you remove the rocker bridges yet?

 

Yes I did

 

1970 old's 350 by the way cutlass supreme 4bbl

 

try pulling a spark plug wire one at a time and listen to see if it changes at anytime. Its had to say, usually I would suspect a broken rocker bridge, but if its not that, it could be a wrist pin or something.

 

Did the spark plug deal no change what's a wrist pin

 

wrist pin is what holds the piston and rod together, that was my .02 cents, not sure what to tell you, check for anything hitting the flexplate / accesories. otherwise it could be a rod knock, which means tear down time, really not sure what it could be

 

I hear ya I had pulled the manifold off all the pushrods are straight and this is something that has occured recently and have had only small problems mostly electrical up til now.
But I'm really stumped because it sounds like its coming from the exhaust manifold or the vlave cover but there's no way lifters could be this loud could they?

 

If you don't have a stethoscope you might try getting a long screwdriver and moving to different parts of the running engine listening. You can put your ear to the end of the handle and the screwdriver tip to the engine and hear vibrations coming through. Just be careful around the fan and belts, especially if you have long hair or loose clothing. Hopefully that can help you narrow down the location.

A number of things could make a sound similar to what your describing. But it sounds like you've eliminated several of them. I've had a bad fuel pump make a racket once. If your not getting oil to one of the rockers that can make a pretty good clatter. Does the drivers side exhaust manifold have the flapper valve in it? Just before it connects to the exhaust pipe?

Let us know if this narrows down the location of the noise.

Whoops! I just read through your post again and see you've got headers. Scratch the exhaust manifold flapper as an possible source!

 

I have this little jimmy rigged tool I use to play doctor stethoscope and I can't seem to pinpoint the noise which is one reason why I still think it might be exhaust but my gaskets are good so I dunno I'm literally pulling hair out

 

Can you tell if its on the driver side or passengers side? Can you hear/feel something at the tail pipe that matches the noise under the hood?

 

80% sure it's drivers side, tail exhaust is in time withthe noise and the noise drowns out the beautiful sound of my exhaust.

 

I've run it without the vave cover and there is slight ticking from rocker arms and such but nothing out of the normal motion sound

 

OK, thinking out of the box a little. I've had a dented oil pan being hit by the crank shaft sound like an engine knock. Once I bought a car that we all thought had a rod knock, but it turned out one of the bolts fell out of the torque converter to flexplate, so the converter was wacking the flex plate.

Could you have dented the oil pan, or damaged the flexplate inspection cover causing something to hit? If you have factory valve covers, could one of those have a dent the rocker is hitting? How about where the headers attach to the exhaust pipe. Are the fasteners all there? Anything loose that could rattle?

 

I bought a car once that developed a knock that sounded like the crank was chewing its way out of the block. I thought I would have to replace the engine. Turned out to be the bellhousing bolts were loose. The whole trans and bellhousing was rocking on the bolts in time with the engine. A few twists of some wrenches fixed it right up. Hope your problem is fixed as easily.

 

My money is on the converter bolts being loose or the flexplate being cracked.



Welcome to ClassicOlds!

- Eric

 

Ok not the bolts on the torque converter, gonna check the flexplte for cracks, also gonna check the other suggestion

 

I recently went through something very similar. Metallic noise that sounded like a marble rolling around in a steel pan. I would have pulled my hair out if I had any.
Checked everything with a screwdriver and could not locate the noise. Finally did what my CO buddies suggested and took off all fan belts. Bingo! P/S pump was the problem. Pulley had a little slack. Fixed the problem and am happily driving again.

This may not be your problem but I feel your pain.

 

Take off all the belts, remove and plug PCV line. Run the engine and see what happens. Just watch your temp.

 

Sometimes when you are in a position when your not sure what is going on. It can be best to try and find someone who may be familiar with the noises to help you..two heads better than one...I know everyone try's to help out but there is a whole lot of info that can bottle neck..find someone who can help you before you may internally damage the motor by continuously starting and stopping.. It's worth to pay a little now than more later..

 

I have run across ONE broken flexplate like that, in a Pontiac. I swapped to an Olds engine for various reasons.

You can also use a piece of HOSE for a stethoscope- it will work well for finding tics and especially vacuum/ exhaust leaks, but beware because when you find an exhaust leak it will be LOUD in your ear.

 

Does your car have a heat riser????? by the exhaust manifold(s)

it is this thing that flaps open and is suppose to open and close etc aside from the other items mentioned I was just thinking this thing could be just rattling around.... just a thought... and do you know if the timing chain has been changed???? my other guess...

 

on second thought the riser really isn't a "loud" chatter rattle..... it isn't the inspection cover for the tranny, you looked at the damper in the front? in the old days if you didn't have a stehoscope you could put a very long screwdriver down ( like the kind to adjust headlights) and "listen" for knocks.... but I am sure things have advanced light years.... and with Harbor freight seldom used tools are cheap enough to buy..

 

I have had one of those cheap stethoscopes for years. I have pinpointed alternator and water pump bearings and broken pushrods and rockers. Makes me feel like Dr. Olds except I don't have a white coat.

 

I've had a flexplate crack twice on me. Both times it was due to trans-to-engine bolts that had come loose. An easy way to check for a cracked flexplate is to temporarily remove the converter-to-flexplate bolts and push the converter back into the trans. Now start the engine. If the noise is gone, it's a cracked flexplate (or a problem in the trans). If the noise persists, look elsewhere.

 

Very loose timing chain?

 

I had a rattle in my 72 Chevy pickup truck and thought it was exhaust manifold too. Turns out I had a blown out baffle inside one of my mufflers, which were 10 years old and looked great from the outside. New mufflers and it was fixed. Even new mufflers can go too.

 

Just a thought, have you made sure your fan isn't making contact with the fan shroud? This happened to me and I was horrified until I found out what a simple fix it was.

 

Do you have crossover blocks installed in the heads to prevent the center exhaust ports from 'crossing over' thru the intake and under the carb?
If so, they are probably loose and rattling.

 

Once lost a spark plug..vibrated loose..sounded horrible.

 

Curious to what the OP found?

 

This happened to me once as well. It was a problem of broken motor mounts. I confirmed the broken mount by putting the trans first in drive and then in reverse and gave it some juice with my foot firmly on the brake. The engine almost climbed outa the engine bay! omg.gif

After replacing the mounts, quiet was restored.

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Ok guys so heres the diagnosis i have since pulled the heads and done everything i could to come to some conclusion. one of the valve spring retainers was worn and i was very close to dropping a valve, now the valves had no carbon and the heads and gasket are in excellent shape all of the other springs and retainers are fine. the noise is for sure coming from the back springs and rockers closet to the driver side firewall. so i adjusted the lifters and torqued them correctly and the noise went away on the first cylinder the orginal sound but now the one closest to the driverside firewall is ticking i have since swapped oil filter and did a very thourough oil change. the noise has died down dramaticly but is still noticeable so i used a zinc additive this also suppresed the noise but is still quite noticable there are no cracks in the flexplate the bolts for the bellhousing are tight and the connecting rod bearings are also fine. no blown gaskets i am however going to switch to a different header gasket felpro seems to be much to thin. short of a new valvetrain and such i am stumped on how to get the sound to go away. thanks for all the input you guys are awesome i brought the car to a local classic car resto mechanic and he suggested the noise was not a serious issue but noticed my waterpump bearing is making a wooshing noise so time to replace that as well. any thoughts on the ticking would be wonderfull i hope i have provided enough information. also oil pressure is good and engine temp is perfect im curious as to how to do the PCV test if someone would further elaborate thanks again your local down the bayou shade tree mechanic -Babafats

 

got some new pics coming soon shes been getting lots of love

 

How do you adjust non adjustable rockers?

 

I took the lash out of the lifters and torqued them down 25intake 30 exhaust

 

I'll ask again too! How do you adjust non adjustable rockers????
pull the dipstick out and run it. Noise gone?

 

You have non adjustable rockers with bridges, did your grind on the mounts?

 

The bridges have two bolts for each bridge, the manual says to take the lash out and torque them to SPEC. The bolt runs thru the rocker into the head. That is the only thing I put a wrench on as far it goes

 

Ok, that will not cure what your issue is. You can buy new rockers and stands through your local parts store, not real expensive. Or, you can grind a little bit off the bottom of the stands to move them closer to the head and give a small amount of preload to your lifter. Make sure they are square. The preferred method is usually to replace.