Tapping sound from stock 383ci 68' Charger

[AR67GTX]

As slow as the tick sounds at idle I'm still guessing an exhaust leak. It would only tick once every second revolution (4 cycle) as the cylinder fires.

 

[Ski 61701]

Like 68GTX mentioned about pulling a plug wire while its running to see if the noise goes away. It might speed up the diagnosis a little.
Not sure on the OPs rocker arms if he is running hyd rocker arms or if they are adjustable. The noise almost sounds to me that one of the baffles that is spot welded in the rocker arm cover may have broken loose and its flopping around just enough that the rocker arms might be hitting it.
You might be able to feel the cover while motor is running to rule it out. As others have mentioned, a stethoscope is a good purchase, and pull trans inspection cover to see if bolts have backed out.
It just sounds too "tinny" and it will probably be something simple .

 

[PurpleBeeper]

As slow as the tick sounds at idle I'm still guessing an exhaust leak. It would only tick once every second revolution (4 cycle) as the cylinder fires.

Also a very good possibility

 

[PurpleBeeper]

Like 68GTX mentioned about pulling a plug wire while its running to see if the noise goes away. It might speed up the diagnosis a little.
Not sure on the OPs rocker arms if he is running hyd rocker arms or if they are adjustable. The noise almost sounds to me that one of the baffles that is spot welded in the rocker arm cover may have broken loose and its flopping around just enough that the rocker arms might be hitting it.
You might be able to feel the cover while motor is running to rule it out. As others have mentioned, a stethoscope is a good purchase, and pull trans inspection cover to see if bolts have backed out.
It just sounds too "tinny" and it will probably be something simple .

Another good point about the valve cover baffles. I had to cut my baffles out & do a little "massaging" on the valve covers for my rockers to fit. The original poster did say "stock 383" in his title though, but good idea.

 

[PeteBell68]

I had the same noise in my engine . It started as a very slight clang sounded like pots and pan lids .
I took the valve covers off , exhaust leak checks etc .
Eventually it was louder and it started to have a hard time running .
It was a cam lob rounded off .
Many miles of race track and abuse finally it gave in .
Hopefully that's what I'm not hearing for you but sounds very similar .

 

[Ranger16]

Follow PurpleBeepers advice and get yourself a stethoscope. It'll lead you right to it. They are worth their weight in gold when it comes to locating noises.

For what it's worth, I'm in the valve train or exhaust leak camp as well.

 

[AR67GTX]

I listened to your video again and although it's impossible to get an accurate timed count of the ticks, it can't be more than about 200 - 300 ticks per minute which tells me it's something occurring at half of crank speed. To me that makes the torque converter unlikely (but would still check) and makes an exhaust leak or valve train issue more likely. Something else to check is your plugs - make sure they are all screwed in and snug and one isn't loose.

 

[The Man Called Lee]

Hey y'all......... sorry for the delay in coming back with an update.

So, I've removed and stripped/dismantled each of the lifters looking for any signs of wear, damage or debris. Everyone of them looked good showing almost no wear at the bottom (that hits the cam lobes). Reckon these must have been replaced at some point.

I've removed and inspected each of the push rods, these look good too. I've rolled them across a glass/mirror surface and they rolled well showing no signs of being bent.

I've removed the rocker arms and the shaft and these show no signs of wear or damage.

I've removed and inspected the fuel pump push rod and that is looking good too, no issues pumping fuel through.

I decided to remove the intake manifold to see how things were looking inside/cam area. Bolts were all tight (first time i've ever removed these or the manifold since owning the car). No debris found and all looked in good order.

I ran outta time to do the other things you guys have suggested so will be cracking on with this again at the weekend - remaining things to look at;

1. Torque convertor bolts/flex plate
2. PCV valve
3. Crank pully

Thanks.

 

[oldbee]

Lacking a stethoscope you can use a long screwdriver with handle at your ear and other end touching suspected locations. Be careful around moving parts. If you don't find anything fire it up with valve covers off and lay your fingers on top of each rocker, you'll feel a problem if it's there.

 

[Ski 61701]

Did you check the rockerarm cover baffles to make sure the spot welds did not break free and the baffle is flopping around?

 

[The Man Called Lee]

Thanks Oldbee & Ski 61701.

Rockerarm cover baffles? I'm assuming these are the small plates inside the covers measuring 2 inch square? Didn't check these but will do.

Update since last;
Got underneath to take a peek inside the gearbox bell housing - by removing the protective metal half plate thingy that's held on by 4 bolts that exposes the bottom end of the flywheel and the flex plate. All was dry inside & no trace of any metal shavings. I hand rotated the flywheel (carefully using a good screwdriver!) 360 degrees to inspect all the way round and the fly wheel looked good. The star-headed bolts securing the flex plate looked good and the heads were not worn as though they might have rubbed/tapped against the bell housing etc.

Took a good look round the headers and the gaskets. I did notice a small drop of oil leaking at the back of one of the headers, was gonna treat the ol girl to some new valve covers and gaskets anyway. I had a blow from a poorly fitted header and from a gasket leak and the sound you normally gets doesn't sound like this tap i'm getting, so quite confident there's nothing to worry about here.

Will have another go at using a long reach screwdriver as an alternative to a stethoscope and run the engine with the valve covers off as suggested. If this doesn't help then my I think my last and only other option is to remove the timing chain cover to see what things look like in there. The tap sounds like it is coming from the front, as also confirmed by a couple of other mechanics.

Will crack on and update next week.

 

[beanhead]

You may not need to, and I don't usually recommend a specific brand because everyone has their own preferences and you always find someone that complains about something you've had success with...but if you drop your header I like remflex brand gaskets, they're all I use on exhaust parts now summit has them..they have sealed for me when none of the other types would...just a thought

 

[Ski 61701]

Ye

Thanks Oldbee & Ski 61701.

Rockerarm cover baffles? I'm assuming these are the small plates inside the covers measuring 2 inch square? Didn't check these but will do.

Update since last;
Got underneath to take a peek inside the gearbox bell housing - by removing the protective metal half plate thingy that's held on by 4 bolts that exposes the bottom end of the flywheel and the flex plate. All was dry inside & no trace of any metal shavings. I hand rotated the flywheel (carefully using a good screwdriver!) 360 degrees to inspect all the way round and the fly wheel looked good. The star-headed bolts securing the flex plate looked good and the heads were not worn as though they might have rubbed/tapped against the bell housing etc.

Took a good look round the headers and the gaskets. I did notice a small drop of oil leaking at the back of one of the headers, was gonna treat the ol girl to some new valve covers and gaskets anyway. I had a blow from a poorly fitted header and from a gasket leak and the sound you normally gets doesn't sound like this tap i'm getting, so quite confident there's nothing to worry about here.

Will have another go at using a long reach screwdriver as an alternative to a stethoscope and run the engine with the valve covers off as suggested. If this doesn't help then my I think my last and only other option is to remove the timing chain cover to see what things look like in there. The tap sounds like it is coming from the front, as also confirmed by a couple of other mechanics.

Will crack on and update next week.

Yes, the baffles are spot welded to the inside of the rocker arm cover directly beneath the pcv opening or the oil fill opening.

Regarding your header, remove the remnants of the old gasket and place a straight edge across the flange. Depending on header quality could be warped and you could forever chase leaks.

 

[64SF]

Like stated above check for an exhaust leak.
Also check to make sure you didn't install one long bolt in the crank pulley and it's hitting the timing cover.(yes I did that)!

Me too.

 

[oldbee]

Did anyone throw out a ticking fuel pump/fuel pump pushrod?

 

[Ski 61701]

Did anyone throw out a ticking fuel pump/fuel pump pushrod?

It would be easy enough to check, put your hand on it and see if you feel something amiss, this and a stethoscope would be good.

Just a thought here, what does anyone think of the possibility of a worn bendix on the starter. Meaning it doesn't retract back far enough into the housing and it randomly hits ring gear ever so slightly? It would be easy enough to check after its removed from the car.

 

[AR67GTX]

I've never had much luck with an auto stethoscope. Touch that probe to an metallic part on the engine and every mechanical sound it makes (normal or otherwise) is instantly concentrated right there. I've never been able to pinpoint any noise with one - has anyone else? Possibly a doctor's stethoscope would work better. I think a piece of 5/8 inch heater hose held up to the ear works better but it's not as easy to get into tight places.

 

[oldbee]

Ski good idea but the audio sounded a little to regular? AR yup there is a lot of noise always there from pumping,rotating,etc. but an abnormal sound is usually there and it just sounds wrong.