Troubleshooting engine vibration- 63 401

[Zimm63]

My engine is vibrating and I need to track it down.  It is noticeable at various RPMs while moving and sitting.   Recent issue. 

 

I read many of the posts on this subject and there are a variety of possibilities.    I have a list of things to look at, and would be happy to hear more on this subject.  To begin with, I have three questions:

 

I put a vacuum gauge on it an found that it is shaky at idle, but steady with just a bit of throttle.  Not sure what that is telling me.  

 

Second question is what other pistons are at TDC at the same time as #1?  I want to check that the timing mark lines up with #1, but its under the AC compressor and hard to get my fancy TDC indictor into play.   I did check the timing with a light and things appear OK, so this may be a waste of time. 

 

Can anyone tell me how to connect a remote starter switch from above?  Or, do I need to put it up in the air and do it from underneath.  That would make it a whole lot easier to do a compression test.  

 

Engine has 82K on it, and I have no reason to think the bottom end has been apart.  It does have an aftermarket cam with a bit of a lope, but thats been there since I got the car 10K miles/ 20 years ago.  The heads were done by Carmen Fasso some years back (2006) when it was blowing smoke at start up.  I broke one of the aftermarket rocker arms installed at the time the heads were done, but Tom Telesco fixed me up with a set of originals.  He has also supplied one of his ignition set ups and rebuilt the carb.  

 

Lots of smart guys out there.  Looking forward to hearing from you.  

 

 

 

 

Edited April 10, 2022 by Zimm63 (see edit history)

[telriv]

Zimm63,

 

1st. the cam with a slight lope will make the vacuum gauge needle bounce around at idle then smooth out with some RPM's. I would consider that normal.

 

#4 is at TDC also when #1 is at TDC

 

If you look at the horn relay/junction box you will see a purple wire. Dis-connect that wire connection & hook up one end of the remote starter switch to the wire then the other end to the battery cable stud. 

What work has been done recently when this vibration started???  Did it just start all of a sudden one day???  Or has it been getting progressively worse as time went on??? Since it's noticeable sitting it should have nothing to do with drive train, drive shaft etc. Although could also be flex plate imbalance???

1st. thing I would try is to remove the fan belts & start the engine to see IF the vibration goes away. 

Next could be a bad harmonic balancer. 

 

Check these things & report back.

 

Tom T.

[1965rivgs]

  A "vibration" is often mentioned as the symptom when the engine has a miss. Do a cylinder power balance test. If you find a cylinder that is not carrying power/affecting engine idle RPM then rule out the possibility the issue is being caused by an ignition related problem. If you find what you think is a bad cylinder now would be the time to do a compression check....or you could do one initially as it's never a bad idea.

  You can use a remote start switch but you can do just as well by using the ignition key. Make sure the choke blade is not closed when doing the comp test if you want accurate results.

  Good luck!

 

Tom Mooney

[R8RS]

I have seemingly the same issue, and we are still trying to figure it out. My motor is a 64 425 and it had 150k miles on it, and it had vibration at various RPM's, and it isn't drivetrain.  I had the motor completely rebuilt and vibration is still there. We have replaced the flexplate and the harmonic balancer, and it still vibrates, and yes, the flexplate is bolted in the correct spot. My mechanic tells me he saw something online regarding the intake manifold possibly causing it.  I am at a loss.

 

[XframeFX]

11 hours ago, R8RS said:

I have seemingly the same issue, and we are still trying to figure it out.

I too have seemingly the same issue, and still trying to figure it out. My 1963 'nail revs smooth but that idle! Thinking electronic ignition next. My Riv has been off road for so long, I don't know what NORMAL IDLE is - ? Certainly not befitting a luxury car off the showroom floor in late '62!

I too have an original bottom-end with about 78K and also have hardened exhaust seats installed back in '93

My final vacuum leak is the power brake booster which I have out for rebuild. It idled slower when bypassed.

Even cylinders have dark plugs, the other 4 are tan. I swapped Primary metering rods and will check those plugs again with more mileage. Original AFB was re-done last summer. Lost my compression test data but they were not far off from each other. Will do a leak-down test this summer.

I was going to check the sloppy original timing chain when replacing the final component in the fuel system that I did not address last year, the fuel pump. But cannot find a replacement pump as yet. 

I have a stripped torque converter fastener. But haven't noticed excessive vibration. But then again, the Dynaflow keeps RPMs steady.

I installed new motor mounts around 1990 but the rubber looks cracked! Will take a closer look and maybe add some chain links on the driver's side regardless. 

 

I've a heard of few smoking nailheads that had a broken piston ring or two when stripped for a rebuild. Mine doesn't smoke.

 

I can't put my finger on any one thing, no silver bullet. Thought I'd add my whoas to this and maybe discover some commonality.

 

[avgwarhawk]

Check the harmonic balancer has not slipped.

[60FlatTop]

I had a similar condition with my '64 Riviera. It turned out to be a cracked piston that disintegrated when my daughter put it under extreme conditions. I have seen three bad pistons on Nailheads, enough to make me suspicious as they age.

 

You can literally put your finger on the tips of all the valve stems if you take the rocker arms off and there is a good chance you will find at least one bad valve guide and a valve with a rounded seat. It will be obvious.

 

Before that you can read your secondary spark voltage with an oscilloscope. I am looking at a new scope and will probably buy a PICO laptop based scope. In recent years I have been using an old Sears engine analyzer with a secondary voltage inductive pickup to isolate dysfunctional cylinders, not as good as a scope but my old Allen scope was too big for the little I used it. The scope or analyzer will pinpoint your cylinder.

 

You can PM me if you want more details of diagnosing with either of those tools.

[TKRIV]

Reply to R8R5: My motor is a 65 425 and it had 50k miles and it had vibration at various RPM's. Just like you had. I had the motor completely rebuilt and vibration was still there. Grrr. We replaced the flexplate, harmonic balancer and just about everything that could possibly be, even the engine mounts. Still it vibrated, and yes, the new flexplate was bolted in the correct spot. The engine was pulled apart again everything was checked again. All OK but we did noticed that pot#5 was cleaner compered to the other pots. Then the builder pressure tested the intake manifold. There was a internal leak. He then blocked off the 4 heat ports and the vibration was gone. As I write this I just can't believe what we had to do to get rid of this vibration. I know this is hard to believe but that is the basic story.

I know of one other mechanic had the same problem many years ago. My take away message is to pressure test the intake manifold if you are doing a complete rebuild and if you do not live in very cold weather block off the 4 heat ports.

Cheers

TomK

[60FlatTop]

#5 would have shown up as random high voltage on the secondary spark due to the lean fuel condition. It would have been hard to pinpoint the defective manifold but not impossible. Hindsight brings up a couple of good ideas but they would be a process of elimination and quite unobvious. An oscilloscope would have been a big help but they are rarely used today. In recent years I had a shop laugh at me when I asked if they used one. That was about the time I started servicing my own "modern" cars.

 

A friend had a great general comment on diagnostics that has stayed with me since the mid-1980's. He said he would be quite reluctant to go to a doctor and ask to check some minor pain he had in his arm. He would have no problem at all holding up his arm with a compound fracture with the bone sticking through the skin and saying "Fix that!"

 

I guess I am intrigued by diagnostics because I have seen so many things disassembled, cleaned, and reassembled that didn't work. They were calling it restoration.

[XframeFX]

12 hours ago, 60FlatTop said:

I guess I am intrigued by diagnostics because I have seen so many things disassembled, cleaned, and reassembled that didn't work. They were calling it restoration.

Acquiring test data from an operating engine prior to dis-assembly is key rather than relying on a visual inspection. The test can be repeated after a fix and if desired results have been achieved, is now valuable baseline data.

A rebuilt module should be tested. I tested the contacts on my "restored turn signal switch" before installing. Seeing nothing was adjustable, an operational test after installation. Did I know my brake lights were NG? No.

Purchasing and installing a reproduced item? Well, hope it's up to standard.

 

Secondary spark Bernie? Isn't there just one every 720 degrees? I am eager to know. I still have an old school Tektronix CRT O-Scope!

[XframeFX]

On 4/10/2022 at 6:30 PM, 1965rivgs said:

A "vibration" is often mentioned as the symptom when the engine has a miss.

Still on this. Important to define if it is a miss firing issue or vibration. The latter is more RPM dependent. Our ICE nailheads are reciprocating machines. Vibration is more evident on rotating components such as drivelines.

 

My thumping 'nail has improved but is still a beast when idling and the steel stampings around it appears to amplify it despite copious application of Dynamat during restoration. Excitation not vibration.

[TKRIV]

My friend's nailhead is sooo smooth. When the engine is warm on idle, take one small step away from the car, if it were not for the noise

of the engine you would bet your life it was no running.

TomK

[60FlatTop]

11 hours ago, XframeFX said:

Secondary spark Bernie?

Secondary spark voltage to clarify primary/secondary.

 

At some early point I adopted the thought of equality for all cylinders in a multi-cylinder engine. That starts with compression. If compression is not equal they just can't run equally. And that needs to be fixed first. The diagnostics can continue to check the air, fuel, exhaust, and other variables but you have to strive to get ever cylinder operating with the same efficiency.

 

My '60 Electra is one of those cars you can stand next to and not know it is running. The Riviera has a loud exhaust that I wanted 10 years ago and plan to remove this Summer. It will be silent then, as well.

 

One thing to always remember "The level of perfection one is capable of achieving is directly proportional to the number of times one is willing to do a job over." I read that years ago and have added a caveat: "The key is willingness and that may be all that is needed".

[Zimm63]

My issue was a failed water pump, allowing the fan to flop around enough to be felt.  Not run across that before with the pump not leaking or the bearing screaming.  

 

Still have a bit of drive line vibration at various speeds.  Need to check the alignment of the driveshaft, per the manual.  I have the special tools but have not gotten to it. 

 

[telriv]

Sometimes the hardest thing to do is check the easy stuff 1st. 

Glad it worked out for you & in some small way I was a help.

 

Tom T.

[BulldogDriver]

Zimm, want to do a solid for the forum? Most if not all of the forum don’t have access to the original Buick special tools used to verify the drivetrain is aligned properly. To verify my drivetrain alignment I had to use a modern approach. What I did was use one of these :

 

WR300 Wixey Digital Angle Gauge Type 2 with Magnetic Base and Backlight

 

along with a lot of reading of this publication from Spicer. Illustration #9 is what I believe the Buick tools verify are within specs without the use of ‘degree’ tools that would have been expensive, bulky, and hard to read under a car back in the day. I believe that the angle gauge of today will give a more accurate alignment.

 

https://www.waterousco.com/media/wysiwyg/pdfs/content/J3311-1-DSSP.pdf

 

This is how I did the procedure. After putting my ‘63 up on car tire stands I set my weight to a average amount that I would drive around with, I took measurements at the starter pad for the engine’s angle, front shaft angle, and pinion yoke. For differential i used the pinion yoke. For that reading I had to pull the driveshaft loose and aligned the yoke vertically and stuck a deep socket with the same diameter as the ujoint in it’s place to get an accurate reading. To zero the digital gauge for initial angle, I used the ‘X’ of the frame where the center carrier bearing is mounted.
 

I’d post my findings but unless someone is installing a 4L60E transmission, the numbers won’t be much help.

 

Ray

 

 

[XframeFX]

4 hours ago, Zimm63 said:

My issue was a failed water pump

So, definitely vibration.

If the cam was changed, then I would think the water pump would have been changed. So, an off-shore pump? I understand the AC version has a bigger bearing and that's the only application available today for replacement (5-Vane).

[tenugent]

9 hours ago, Zimm63 said:

My issue was a failed water pump, allowing the fan to flop around enough to be felt.  Not run across that before with the pump not leaking or the bearing screaming.  

 

Still have a bit of drive line vibration at various speeds.  Need to check the alignment of the driveshaft, per the manual.  I have the special tools but have not gotten to it. 

 

Read this on here years ago.Drive shaft has to go in the way it came out.Turn it over 180 and see if the vibration goes away ?

[60FlatTop]

12 hours ago, XframeFX said:

then I would think the water pump would have been changed.

I have been doing all I can to repair or rebuild any of my existing original components.

 

One thing I especially avoid is "kits". Many times you see front end of brake kits. I bought a Buick front end rebuild kit years ago. All the components came in plain brown boxes of unknown sources. One ball joint nut was so poorly machined it would not tighten. I threw it out and used the old one.

A friend was over last week going through his needs for a brake job on his 1951 Studebaker. He had found a kit. We listed the cost of rebuilding and lining his existing parts. The cost was $70 more using known quality parts and doing the job "Ala Carte". That's our new term and ala carte it is.

[Zimm63]

12 hours ago, XframeFX said:

So, definitely vibration.

If the cam was changed, then I would think the water pump would have been changed. So, an off-shore pump? I understand the AC version has a bigger bearing and that's the only application available today for replacement (5-Vane).

I had a 3 vane pump in it.  New one was 5 vane.  Pretty sure I put a pump and fan clutch on it when I first bought the car 20 years ago.  Found the receipt for the clutch, but not the pump.  May not be remembering correctly.  

 

Always grateful to Tom T for showing me the way.  

 

 

[XframeFX]

11 hours ago, Zimm63 said:

May not be remembering correctly.  

Man, my issue exactly.

Some things I remember, others, not. Lower Rad outlet interference, temporarily installed incorrect rad? My 1965 ST400 core, mint '64 dashpad. Where did I acquire those parts?

I do remember my nail idling rough after a 1993 valve job w/inserts and Felpro headgasket.

 

I believe my waterpump is original. I have a new Cardone (Chinese) in a box as a backup spare. Again, 5-vane with the bigger bearing. But I'm learning of a few failures with replacement pumps.

 

I remember asking a long time owner of an Auto-electric shop for a bearing an brush kit for a Delco 10DN alternator. "Garbage!" his response. "I'll get you good bearings and brushes" A-La-Carte it is.

Rebuild, Rebuild!

Edited April 20, 2022 by XframeFX (see edit history)

[steelman]

It was my understanding the the original water pumps used brass bushings, not bearings on the shaft? That was most of the reason I went with this one when mine failed. New and uses bearings, not bushings.

http://www.taperformance.com/proddetail.asp?prod=TA_1538B

[RivNut]

The TA Performance pump looks like a Flowkooler pump. 

[XframeFX]

11 hours ago, RivNut said:

The TA Performance pump looks like a Flowkooler pump.

Yes, with what appears to be an anodized blue impeller.

[RivNut]

The Flowkooler pump has a completely different style impeller. It should move a lot more water is the same amount of time.

Edited April 21, 2022 by RivNut (see edit history)

[telriv]

It's really not about how much coolant will flow BUT the amount of heat taken away by the radiator that's able to do it's job.

 

Tom T.

[Turbinator]

On 4/21/2022 at 11:34 AM, telriv said:

It's really not about how much coolant will flow BUT the amount of heat taken away by the radiator that's able to do it's job.

 Tom, will the severe duty fan clutch help reduce heat from the radiator by running all the time? Next question- does the severe duty fan clutch engage all the time while the engine is running? Reason I ask is sometimes there is quite a loud noise coming from under the hood. I check engine temp and everything is relatively cool.

I can say with certainty the noise is audible. I can also say sitting at stop lights with the AC on the air is much cooler than with original fan clutch.

Turbinator