jlr253
New Member
My 383 has developed a metallic tapping noise. Sounds top end. Here's a video of the sound... Any ideas or where to start?
383 noise
- Thread starter jlr253
- Start date
You can listen more closely with a stethoscope or a length of rubber hose. Pulling plug wires one at a time can help isolate a noise generated by piston/connecting rod issues. Good luck-hope it's not expensive!
Mike
Mike
Shorthorse
Well-Known Member
Couldn't really tell from your video. These might look stupid but they can be handy. Especially for listening to tappets.
$4 at Harbor Freight.
$4 at Harbor Freight.
1967coronet440
Well-Known Member
Hard to pinpoint without hearing it in person, don’t like that sound though.
Like short hose said that stethoscope will help you pinpoint it
Like short hose said that stethoscope will help you pinpoint it
Yatzee
Well-Known Member
Locating the sounds eminating from an engine can sometimes be difficult but there are a few basic procedures that can help. While the engine is running remove the oil filler cap on one rocker cover and a breather cap on the other to see if the sound is coming from the upper valve train. Using a 1/2 piece of hose pressed against the oil pan with the engine running will enhance any lower knocks etc. If the timing chain is creating the sound, your timing marks will not hold steady. The torque convertor bolt(s) could be rubbing on the inspection cover if they've come loose. Accessories that have ball/roller bearings ( water pump, power steering pump etc.)can transmit sounds down their mounting brackets to the block. Remove the belts and run the engine briefly to eliminate this as a source. And using the hose listen for noises from the oil pump and fuel pump push rod. Use extreme caution when poking around a running engine. You may have to remove the rocker covers to inspect for a broken valve spring or bent valve pushrod striking on it's passage through the head. Good luck.
PurpleBeeper
Well-Known Member
Yatzee & these other guys have some good advice.
1. Check oil level
2. Check oil pressure if you have a gauge.
3. Try to isolate where the sound is coming from (driver/passenger/front/back) of engine.
If it's coming from under one of the valve covers, remove that cover and:
a. Look for some part of the pushrod/rocker arm combinations that "look loose"
b. Pull of rocker bar & inspect each end of every pushrod, the contact "cup" of the rocker arm, & place each rocker arm (after cleaning) on a flat surface to see if it's bent (assuming stock rockers). BE SURE to mark everything & put it back in the same location & pushrod pointing the same direction.
If it's coming from the front of the motor (& you've determined it's not any of the valve gear):
a. check fuel pump pushrod for being "galled"
b. check water pump, alternator, p/s pump as mentioned for something being "loose"
c. If all else fails up front, check timing chain (I don't think this is likely if car is running OK, but possible)
If noise in the back of the motor: (least likely I think)
a. check for loose clutch/flywheel bolts OR loose torque converter bolts
Good Luck Sir!
1. Check oil level
2. Check oil pressure if you have a gauge.
3. Try to isolate where the sound is coming from (driver/passenger/front/back) of engine.
If it's coming from under one of the valve covers, remove that cover and:
a. Look for some part of the pushrod/rocker arm combinations that "look loose"
b. Pull of rocker bar & inspect each end of every pushrod, the contact "cup" of the rocker arm, & place each rocker arm (after cleaning) on a flat surface to see if it's bent (assuming stock rockers). BE SURE to mark everything & put it back in the same location & pushrod pointing the same direction.
If it's coming from the front of the motor (& you've determined it's not any of the valve gear):
a. check fuel pump pushrod for being "galled"
b. check water pump, alternator, p/s pump as mentioned for something being "loose"
c. If all else fails up front, check timing chain (I don't think this is likely if car is running OK, but possible)
If noise in the back of the motor: (least likely I think)
a. check for loose clutch/flywheel bolts OR loose torque converter bolts
Good Luck Sir!
DCCoronet
Well-Known Member
I had a slightly bent pushrod that would tap intermittently against the opening in the head where it passes through. I suppose it was intermittent because the pushrod rotates while running. Its an easy check out.
jlr253
New Member
thanks for the advice everyone. an update where i'm at
engine is holding good oil pressure (75 at cold, 50 at warm idle) idles well but has a terrible miss under load in gear. Cold compression check. All 8 bt 125 and 130. i checked the timing, it is holding the timing mark, and set at 16 degrees at idle. i took off valve covers. everything looked good there. i started it, everything looked like it was moving properly. Noise sounds like its coming from more the front. I still pulled off the intak everything there looks good. I checked the tc bolts. Those are tight. The noise is very intermittent but intense. I am going to stop tonight to get a stethoscope and hoping its not bottom end.
engine is holding good oil pressure (75 at cold, 50 at warm idle) idles well but has a terrible miss under load in gear. Cold compression check. All 8 bt 125 and 130. i checked the timing, it is holding the timing mark, and set at 16 degrees at idle. i took off valve covers. everything looked good there. i started it, everything looked like it was moving properly. Noise sounds like its coming from more the front. I still pulled off the intak everything there looks good. I checked the tc bolts. Those are tight. The noise is very intermittent but intense. I am going to stop tonight to get a stethoscope and hoping its not bottom end.
moparnation74
Well-Known Member
I was thinking the same thing....or a bad fuel pump arm/spring
Sixpactogo
Well-Known Member
I too vote for the fuel pump. I once had the same issue. Ended up the fuel pump was the problem. The spring on the lever was weak and the rod was not held tight enough causing the rattle.
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