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Vibration at idle and at speed

ncarter124

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Hoping some experts can chime in here...

The car is a '70 Charger R/T SE with a 440 Six Pack mated to a 4-speed manual - car has no A/C or Power Steering. I am experiencing a vibration in the engine somewhere, but I can't figure out where.

Behavior: This occurs at idle, at speed and with the clutch in or out, so in my mind it seems to be either the harmonic balancer or the flywheel. The engine seems 100% healthy and this does not seem to be a cylinder contribution issue as I can feel all over the engine at idle and I don't feel/hear/see this vibration if that makes sense.

Also, and I will try my best to describe this verbally, but the vibration feels rotational to me. If you are sitting in the drivers seat you feel almost like you're experiencing the effect of leaning against a washing machine that's out of balance - which leads me to believe it is indeed in the rotating assembly vs. a cylinder contribution scenario.

Thanks! Any input is appreciated!

20190107_181805633_iOS.heic.jpg 20190107_183651991_iOS.heic.jpg
 
you know a video of the engine running might help a little
Yup I actually plan on doing that tomorrow once it's daylight and I have time to do so. I've been working nonstop this week and just haven't had the time - I will upload it tomorrow though with commentary describing it as best I can.
 
Car new to you?
If not, any recent changes?

Have you taken a peek at the engine mounts?
 
Car new to you?
If not, any recent changes?

Have you taken a peek at the engine mounts?

Yeah car is new to me. The previous owner has been pretty honest about everything on the car so I don't think this was something he tried to hide from me.
As for engine mounts, I have considered that but wasn't sure just due to how steady the vibration is. As stated above I do plan on getting a video of it, but yeah engine mounts are my #3 suspect behind the rotating assembly components.
 
First thing I would try is removing the fan belt and running the engine.
Easy enough to do and would assist in isolation.
 
car is new to you. Six pac engines were externally balanced and have heavier rods and take a particular balancer and maybe the flywheel to, I can't remember but I have known of 440's etc. with the wrong balancer installed by the unknowing builders. If I didn't find a simple solution I'd find out more from the previous owner. An experienced engine builder that doesn't know BB Mopars and has a pile of parts from someone that is not an expert could end up a cluster eff. Good luck.
 
Welcome! Did you get the Charger in Tucson? Looks like one a member on here was selling.

Edit - just saw your original post, nice car and congrats!
 
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These are good suggestions above. My 2-cents...First thing, checking the motor mounts by seeing if the engine moves a lot when you rev it up is a GREAT thing to check first. It will typically lift up on the drivers' side.

Second, ask the last owner about the short block of the engine. Q: Does it have the larger "six pack" rods? Q: What harmonic balancer was used? Q: What flywheel was used? Q: Was the engine balanced?

Six Pack & high-performance '70-'73 440's take a special harmonic balancer & flywheel too.

- You can see the harmonic balancer if you look just behind the main pulley at the bottom of the engine in front. A "six pack" balancer should look like this (see offset weight in the front/middle) & is about 1" wide
upload_2019-1-11_8-9-27.jpeg

- A "small rod" balancer should look like this (symmetrical all the way around in front) & is about 1" wide
th?id=OIP.bdzqmfMQ4SOPxxO3N_TtGgHaG6&w=227&h=211&c=7&o=5&pid=1.jpg

Keep in mind that a 6-pack setup can be installed on any 413/426W/440 engine, regardless of crankshaft/rods/etc. The engine "could" be a small rod/six pack rod/cast crank engine & still have a six pack on it.

If the engine has a cast crankshaft, the harmonic balancer will be about 2" wide (instead of 1" wide like the two balancers above)...like this. They often (if not always) actually say "cast crank" on them.
upload_2019-1-11_8-18-14.jpeg
or this
th?id=OIP.6_D0Pu0mbK37TH9ln3jZwQHaGN&w=242&h=194&c=7&o=5&pid=1.jpg
 
You could have a fouled plug too. Lots of starting and moving the car without a good warm-up.

Have all of your plug wires loose on the cap. Start it up and pull one at a time and see if one doesn't make a difference. That will be the one that's fouled.

If you have a Inferred gun you can tell which cylinder isn't firing by the cold exhaust port on the exhaust manifold or header.
 
You could have a fouled plug too. Lots of starting and moving the car without a good warm-up.

Have all of your plug wires loose on the cap. Start it up and pull one at a time and see if one doesn't make a difference. That will be the one that's fouled.

If you have a Inferred gun you can tell which cylinder isn't firing by the cold exhaust port on the exhaust manifold or header.
This is a good idea.... BUT DON'T LEAN ON THE CAR OR TOUCH IT ANYWHERE WHILE DOING THIS....or you will get one hell of a shock! I have a "brand X" car with Accel ignition coils that literally say "Danger, Lethal Voltage" on the side of them.
 
This is a good idea.... BUT DON'T LEAN ON THE CAR OR TOUCH IT ANYWHERE WHILE DOING THIS....or you will get one hell of a shock! I have a "brand X" car with Accel ignition coils that literally say "Danger, Lethal Voltage" on the side of them.

I guess I could have mentioned, use insulated pliers. Normally after the first one bites you, you'll head to the plier drawer.

My former Father-in-law would be under the hood of a car and ask for a wrench. You would hand it to him not knowing he had the end of a plug wire in his other hand!
electrician-smiley-emoticon.gif


Charged up condensers laying on the work bench was another one of his favorites.
 
car is new to you. Six pac engines were externally balanced and have heavier rods and take a particular balancer and maybe the flywheel to, I can't remember but I have known of 440's etc. with the wrong balancer installed by the unknowing builders. If I didn't find a simple solution I'd find out more from the previous owner. An experienced engine builder that doesn't know BB Mopars and has a pile of parts from someone that is not an expert could end up a cluster eff. Good luck.

That makes sense. This car is a U code car so it was born a 4bbl and the Six Pack was added at some point.
 
Welcome! Did you get the Charger in Tucson? Looks like one a member on here was selling.

Edit - just saw your original post, nice car and congrats!

Yup that's the car. It has some issues but the price was good and the fundamentals of the car seem good so I am happy with it.
 
These are good suggestions above. My 2-cents...First thing, checking the motor mounts by seeing if the engine moves a lot when you rev it up is a GREAT thing to check first. It will typically lift up on the drivers' side.

Second, ask the last owner about the short block of the engine. Q: Does it have the larger "six pack" rods? Q: What harmonic balancer was used? Q: What flywheel was used? Q: Was the engine balanced?

Six Pack & high-performance '70-'73 440's take a special harmonic balancer & flywheel too.

- You can see the harmonic balancer if you look just behind the main pulley at the bottom of the engine in front. A "six pack" balancer should look like this (see offset weight in the front/middle) & is about 1" wide
View attachment 703663
- A "small rod" balancer should look like this (symmetrical all the way around in front) & is about 1" wide
View attachment 703668
Keep in mind that a 6-pack setup can be installed on any 413/426W/440 engine, regardless of crankshaft/rods/etc. The engine "could" be a small rod/six pack rod/cast crank engine & still have a six pack on it.

If the engine has a cast crankshaft, the harmonic balancer will be about 2" wide (instead of 1" wide like the two balancers above)...like this. They often (if not always) actually say "cast crank" on them.
View attachment 703667 or this View attachment 703669

THIS was immensely helpful! As I stated in another reply this is a U code car with a Six Pack added so I'll bet you anything this is the issue. I had planned on getting a video on Friday but our Dachshund had a back injury that resulted in an emergency visit to the vet and while she is doing much better, it just trashed the entire weekend and to be honest the Charger really wasn't a priority.
 
You could have a fouled plug too. Lots of starting and moving the car without a good warm-up.

Have all of your plug wires loose on the cap. Start it up and pull one at a time and see if one doesn't make a difference. That will be the one that's fouled.

If you have a Inferred gun you can tell which cylinder isn't firing by the cold exhaust port on the exhaust manifold or header.
That could be though it really doesn't seem to be a miss if that makes sense. I can't speak for the previous owner but whenever I start it I drive it and it really seems to idle silky smooth, no vibration out of the exhaust/engine, but it's there - that probably doesn't make sense, but while I am not ruling it out, I am very heavily leaning on it being a balancing issue somewhere as opposed to a cylinder contribution issue.
 
This is a good idea.... BUT DON'T LEAN ON THE CAR OR TOUCH IT ANYWHERE WHILE DOING THIS....or you will get one hell of a shock! I have a "brand X" car with Accel ignition coils that literally say "Danger, Lethal Voltage" on the side of them.
Yeah, I don't mess with stuff like that.
 
That could be though it really doesn't seem to be a miss if that makes sense. I can't speak for the previous owner but whenever I start it I drive it and it really seems to idle silky smooth, no vibration out of the exhaust/engine, but it's there - that probably doesn't make sense, but while I am not ruling it out, I am very heavily leaning on it being a balancing issue somewhere as opposed to a cylinder contribution issue.

Some cylinders when not firing don't seem to effect the smoothness as much as others do. Just something to check that doesn't cost anything.

Check what balancer is on the crank. Check for weight or no weight on the torque converter/flywheel. See what numbers are on the front engine pad and above the oil pan. That might tell you what you are working with. It won't tell you whether you have six pack rods or not.

Did you run it with the fan belt off? Fans and alternators can vibrate.

Cover all the bases. Before tearing anything apart. Good luck!
 
Some cylinders when not firing don't seem to effect the smoothness as much as others do. Just something to check that doesn't cost anything.

Check what balancer is on the crank. Check for weight or no weight on the torque converter/flywheel. See what numbers are on the front engine pad and above the oil pan. That might tell you what you are working with. It won't tell you whether you have six pack rods or not.

Did you run it with the fan belt off? Fans and alternators can vibrate.

Cover all the bases. Before tearing anything apart. Good luck!

Oh absolutely, like I said, I am not ruling it out at all, it just isn't my top suspicion. That being said I always tend to check the easier things (plugs and wires) as opposed to the more difficult stuff (rotating assembly). My profession is IT so I do troubleshooting for a living and more often than not I have screwed myself by assuming the issue is more complicated than it really is.

As for the fen belt off, that's my plan in a couple days I hope. I had a hell with our dog having to take an emergency trip to the vet so the car didn't get touched.
 
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