engine shaking badly

[slowpoke]

truck is shaking under power lift throttle goes away instantly use engine brake shakes even worse
after about 1/2 hour without using jake at all engine smooths out. going to pull rocker cover tomorrow hoping its just something in the jake system. not sure what to look for, going to try to find some info on here. hopefully not a sign of something really bad. if anybody knows of a post i could read . engine cm 871 de mand

[Steen]

I got very bad shaking when the engine is cold. It sounds like there not enough fuel going. My fuel tanks are full. When engine warms to about 150f gets smooth again with no shaking.
No faults on
Any idea what can be the reason/s for that ?

[Nilao]

Year and model of engine?

[Steen]

2009 isx 871 425hp

[slowpoke]

have rocker cover off 3 jake rocker moving when idling others are stationary push in center of solenoid 3 front jakes come on they all move look good rears are the same checked top end set still same 15 and 28 . push down on roker bounces back up to detent 2 of them push back onto cam and stays there until engine runs they are two that don't move while idling. so should rockers move will idling or should they be stationary

[Nilao]

The engine brake rockers should be stationary unless activated. Most likely the springs in the detents are shot, possibly the shaft is bad. As far as rough idle it could be an actuator on its way out, or leaky injector. I know if it is cold outside mine is a bit rougher and noisier until it warms up a bit but thats usually a matter of 1 or 2 minutes max. The ECM has a warm up mode that changes the onjection timing and turbo closure in order to help it warm up faster also.

[smorgan87]

id suggest rebuilding those jakes and dont run it until u do.

[slowpoke]

dropped off at dealership told them what i saw under rocker cover. i'll see what they do. if they don't fix it i'll attempt it myself. thanks for the warning about not running it. engine only ten month's old seems odd jake's are worn out. so rebuilding jake's if they don't do it do i order new shaft's and rockers or do i rebuild the rocker's that are there?

[Rawze]

(11-20-2018 )slowpoke Wrote:  dropped off at dealership told them what i saw under rocker cover. i'll see what they do. if they don't fix it i'll attempt it myself. thanks for the warning about not running it. engine only ten month's old seems odd jake's are worn out. so rebuilding jake's if they don't do it do i order new shaft's and rockers or do i rebuild the rocker's that are there?

maybe make video of what you are seeing and post on youtube?