I've got an engine vibration at 3k+ rpm's. Any gear, any speed, even parked in neutral, although its worse in gear than when in neutral. Any ideas or is this normal? I wouldn't think that its normal though.

Thanks, Aaron

 

Motor mounts???

BTW...I wouldn't free spin the engine to 3K

 

Why not?



What sort of a vibration are we talking here? Like a misfire or breaking up, a buzz, an unsteady feeling?

 

When I free revved it, once, I didn't just put the fuel peddle to the floor. I slowly pushed it down until 3k to make sure it didn't flare higher than I wanted.

Its not a misfire, or breaking up, it just vibrates the whole truck. Kind of like unbalanced tires doing 80mph.

It could be motor mounts they look OK but its really difficult to get a good look at them.

Oh and i have the "60lb" valve springs, both intake and exhaust.

 

It sounds like a misfire to me.

 

or what about a bad injector?

 

That would cause a misfire.

 

ahh yes... me grasshopper!

 

The injectors are new piers units with less than 10k miles on them, so I doubt it would be the injectors but anything is possible. I was thinking more towards the injector pump. Could that be the issue?

 

just a thought, my motor threw a fan blade and my motor wouldn't rev past 2300rpms with out shaking, maybe your blade is bent or partialy broken, just a thought.


jason

 

Thanks for the thought, that had crossed my mind, I checked the fan and it is solid, as far as the clutch and bearing. I will double check that all the blades are secure though.

 

Harmonic balancer?

 

bad lift pump not delivering enough fuel to the IP?

My truck would vibrate through the pedal for some reason (near WOT or near 3k) and it stopped after a new lift pump.

Just a thought from a total mechanical rookie.

 

Pop the belt off and rev it up to rule out the fan.

 

You might have lost a spring or two in the pressure plate, which could cause a vibration.