6.2L Diesel vibration / HELP!

[rhinob]

I have a 6.2L diesel that is vibrating when it runs. It has what feels like a dead miss, but all cylinders are producing heat at the manifold, and all diminish power when the fuel line is cracked at the injector. There's very little smoke, at any power setting. Alternator, P/S pump, and water pump are the only accessories. The harmonic balancer is definitely old.

I've heard the possibilities of a broken valve spring, plastic cap holding rocker arm, harmonic balancer, sticky lifter, etc. I've ordered a balancer since the one on the engine is ancient and hard as a rock. Beyond that, I'm trying not to waste a bunch of time and thought I'd shoot this out there to see if anyone else has dealt with these symptoms and what their remedy was.

Does anyone know if this engine is internally or externally balanced?

Would love to hear some ideas.

Thanks much,

Den

 

[Westech]

Balancer is a good shot.

 

[Tanner]

GM's 6.x diesel engines are external balanced...

If you want to spend some coin, Fluidamper offers a 6.2 & 6.5 viscous fluid damper, but Summit or Jeg's will tap your purse for about $400+

'Tanner'

 

[LTWVARNG]

you mean its not supposed to vibrate?

 

[bassetdeuce]

GM's 6.x diesel engines are external balanced...

If you want to spend some coin, Fluidamper offers a 6.2 & 6.5 viscous fluid damper, but Summit or Jeg's will tap your purse for about $400+

'Tanner'

Yeah, that price hurts but at least it is made in the USA. Is the damper even still available from GM?

 

[4x4 Forever]

You can try, but I doubt it. The parts guy I gave been using for the past 20+ years told me that GM got rid of all the pre 88 stuff. Some of the dealers MIGHT have then stuck in their "back 40". You can have your dealer do a dealer search, I wouldnt your breath though. If you do find a suppy, please let us know, as we all have inquiring minds !!

Good Luck!

 

[kennyw]

Last engine I had with vibration issues had a cracked block that lead to a broken crank... and I put a new balancer on it and pulled the pan to inspect it before I put it in my truck. I found nothing I could see with the naked eye at that time, but 9 months later it gave out.

 

[stampy]

I assume its vibrating in park and it is not a running gear issue and you have changed fuel filters? Have you checked compression in the cylinders?

 

[Radioshop]

I got a 6.2 balancer from Rock Auto. It was Dorman part and went on with no excitement. As it turned out my problem wasn't the balancer, it was a warped lower pulley.

 

[rhinob]

Thanks for all the advice. Will work on the issue today.

Den

 

[doghead]

It looks like this is the correct Dorman part number. Dorman 594128

 

[Somemedic]

Worn out motor mount?

I noticed my truck rocking hard. Replaced the power steering pump and the torqued bracket that it was on. Put some big washers on the mounting nuts/bolts and it sure did seem to deaden the rocking.

I might look up a new balancer next year. Mine seems ok for now. Front main seal is a little weepy, so when it gets fixed new balancer and timing chain.

 

[stump]

May have a bent conecting rod from either.

 

[rhinob]

Here's the answer: Flywheel NOT counter-weighted, wrong setup. Welded the counterweight from an old flexplate to the flywheel and voila, smooth as a kitten. Go figger.

Thanks for all the help!

Den

 

[Towerguy1]

I had to replace both the balancer and the lower pulley. Both were bad, easy to spot when running. Gives you the shivers because it looks like the crank is broke. Got lucky!