Odd Engine Vibration

[FEF]

I have an odd engine vibration that happens with the vehicle stationarry.

- If I had to guess, it's about 8-14 Hz.
- Lasts about 1.5-2 seconds with the intensity getting greater then none.
- Frequency or intencity does not change with engine RPM.
- It appears to go away, or is less noticable, with higher engine RPM. But at that point, it's reving pretty good. I can't really tell with other vibrations going on.

I've not experinced anything like this. Pullies out of round changes with RPM. Everything I can think of (flywheel, TC, all the rotating stuff) changes with RPM

Could it be the harmonic balancer? I've not seen one of those fail. But I'd guess the harmonics would change with frequency (RPM) too.

I'm stumped


oh, sorry for the poor spelling. I'm really looking forward to forum spell checkers. :cool:

It occurs to me, this might go in the tech forums. Sorry about that.

[Robyn]

The 6.2 can and does experience a nasty harmonic that sets up in the v belts.
This is many times caused by the water pump going away.

Remove the belts and see if the bad vibes go away too.
Check the water pump for a loose bearing as well as other items in the accessory train.

Good luck

Robyn

[FEF]

The 6.2 can and does experience a nasty harmonic that sets up in the v belts.
This is many times caused by the water pump going away.

Remove the belts and see if the bad vibes go away too.
Check the water pump for a loose bearing as well as other items in the accessory train.

Good luck

Robyn
Waterpump? HUMmmmmmmmmm.

True, pulling belts is the next step. Thing is, I really didn't think I was going to have to replace all this stuff. I may as well rebuild the engine when I pull it for the conversion. Oh well, such is life....

Thanks for the help