Rough idle and engine "rocking"

[chancethegreat]

Hey all. I don't have much time but my TB is idling horribly and feels as if the engine is rocking side to side at certain points. I checked the oil and I was about 4 qts low(not sure how). Filled her up and problem is still here. She is only rough at idle, a little gas and she is fine. It almost feels like a fuel pump is going out(that has happened before). While she is doing this rough idle my battery gauge is moving as well with each "bump", normally down.

I haven't had time to read through threads and things since it just started happening this morning while I was working.

Any direction would be appreciated.

 

[HARDTRAILZ]

New plugs.

Clean Throttle Body.

Check for moisture in fuel.

Any codes or dash lights?

Run the piss out of it for a bit and see if it cleans itself out.

 

[chancethegreat]

Plugs were all done about two years ago with OEM plugs. Throttle body done about a month ago. No codes or dash lights. Will check for moisture in fuel, and give her a workout.

 

[tsmith1156]

Plugs were all done about two years ago with OEM plugs. Throttle body done about a month ago. No codes or dash lights. Will check for moisture in fuel, and give her a workout.

Sounds like what mine was doing, did you have any oil in any cylinders when you did your plugs? It may be worth checking, I did my valve cover gasket and it has seemed to clear up but I had oil in several cylinders

 

[mrrsm]

Watch this video to locate the purpose and R&R of the CPAS... Camshaft Position Actuator Solenoid. If yours has an Oil Filled Plug connector... this video is just about as good as it gets in how to do the repair. This engine has no EGR Valve and with 25 Degrees of Exhaust Camshaft Actuator movement possible to handle variations in Exhaust Valve Timing... if it gets clogged screens due to a Low Oil Supply and Dirty Motor Oil... the engine will misbehave at idle:

Also... This linked thread has a concentrated amount of information that covers many other possibilities... but dial in on #12 first as it concerns the CPAS and the CPS Solenoid-Sensors that will affect the idle of your engine quite a bit if these are involved. This entire post will give you a good grounding from many other Members providing in-depth observations and suggestions...Well worth the Read:

http://gmtnation.com/forums/threads/bad-knocking.16123/#post-514903

 

[gmcman]

When your engine is idling bad, what RPM's is it at? Do you have a "service engine soon" light illuminated on the dash?

Does the engine make and rattling or light knocking aounds? How long was the oil level that low? Hopefully you don't have any accelerated lower cylinder or ring wear.

 

[07TrailyLS]

Never rule out motor mounts. Mine are SHOT as I'm typing this and my engine idles TERRIBLY from it. When I have her in park or neutral, she idles smooth as butter. The 4 quarts low is kind of a big deal. I just turned 100 k and my trucks been burning 2 quarts every 3500 miles since I bought it with 50k on it. I wasn't worried too much because I just did my first plug change and there was no oil present in my cylinders. You may wanna run a compression test and maybe use the torque app to check your fuel trims and see if your long term changes drastically over time. It's suppose to be as close to 0 as possible.