Resolved Vibration - RESOLVED

[SrKegler]

I seem to be getting some vibration in the engine. Happens about the same RPM as it normally does without balance shafts. Hasn't seem to have gotten any worse, but is definitely louder than normal.

Things I've done.

Replaced all timing components except tensioner arm. Drew a line across harmonic balancer. Have driven about 500 miles, lines are still straight, bolts are tight. Even put on a new front cover in case it was rubbing.

Only thing left that I can think of is the oil pump gears. Researching I found several references to the stubby shaft without the groove in it. Engine was rebuilt in 2010 by a shop in St Louis. Not sure if they used a kit off of ebay or not. Front shaft is still in place.

Looking for any suggestions on what else the problem could be. Vibration goes away about 3500 rpms.

Might just be paranoid but after 20 yrs of driving this car I notice any changes in sound, handling, etc.

Next step for me will be to replace the front case and gears.

Sorry, not smart enough to figure out how to take or post a video on here. Just clutching at straws and making sure I touch all bases.

 

[rough]

Oh I'm sure you're smart enough to post a video on here, you actually just put them on youtube, then use the media right above where you type next to the smiley face and picture, you just paste your youtube link there

Are you sure it's motor related and not a clutch, flywheel?

 

[spoolin93]

Oil pump runs on a 1 to 3 gear ratio with balance shaft. The pump will roll and fall in a "rest" position. If the pump is not in time and in the rest stack position it will be wrong and will vibrate like crazy.

 

[spoolin93]

Slack sorry not stack

 

[SrKegler]

Done a balance shaft delete when the belt took out my timing belt.

Positive it's motor related. Runs from about 2500 to 3500. Makes my dash vibrate. Clears up quite a bit after 3500.

 

[spoolin93]

Hard to tell without seeing it. Only other thing is possibly the harmonic balancer got damaged during the install?

 

[SrKegler]

Tore it apart again today. May have found the problem. Tensioner arm had a divot worn in it. Was gapped correctly at 3.8mm but with the divot the belt was probably too loose. When you only have .4mm to play with, doesn't take much. Since I've got it down this far, might as well replace the front case, stubby shaft and pump gears and the arm.

 

[Lou98GSX]

If you delete the balance shaft you will get a vibration .

 

[rough]

Hope that's the fix! Report back either way

 

[SrKegler]

I realize that. Thanks. BS has been deleted for about 5 years. The vibration is much greater than what I've been used to. I used to not even notice it. Ordering new parts today. While I'm waiting going to rebuild the throttle body, put in new injector seals.

That reminds me, since I'll already have the front case off, might as well pull the pan, reseal it, been wanting to run some allen head bolts thru the oil pan with some o-rings to stop the leak around the threads for the drain line.

Seems like I can always find something to fix while I'm at it.

 

[SrKegler]

RESOLVED!!!

Was just getting ready to order parts in when the famous belt squeal started on. Went to the store, got new belts, found out the nut had came off the bolt for the alternator. Holes were wallowed out on the alternator so I reamed them out, put in spacers and put a self locking nut of the bolt.

Vibration is gone. Some times it's the simplest things. After 20 years driving this car though, I knew something sounded different.