06 dodge ram hemi engine knock at idle from bottom of engine

Check engine compression and compare. then test running engine compression most engines have about 130-170 cranking compression and about 90-110 running compression. OR bring that cylinder to its Top Dead Center compression stroke apply air to the cylinder and check to see where the air is going open throttle plate bad intake valve, from exhaust pipe bad exhaust valve, from oil cap piston rings.

I thinc the sensor needs inspecting-you need a repair book or go to chilton online for exact location

Is this a knock or clicking sound? Hemi's are known for breaking exhaust manifold bolts and causing a clicking sound which is a exhaust leak.

I had the same problem with my, 03, hemi. I did not wait 15 min. turn off and back on was all that was needed to reset, "red flashing light lower right hand ". though another 8 or 9 on off's, Engin Light also goes off, untill next time. All i did was pulled off my Air Intake box and hose, so i could get to butterfly on throttle bodie, sprayed carb cleaner in there. and it was very dirty. after put back togather, give it a few.... mine did not start right up, when it did idle real ruff even died few times...Once the computer re adjusted ran like it did when i bought it....that was 2 weeks ago, still no eng light, no flashing red ones either.

spray starting fluid into the air intake, if it starts your electric fuel pump has failed, let me know what u find.

YOU COULD BE HAVING ENGINE MISFIRE.DUE TO BAD SPARK PLUGS AND WIRES.ALSO DIRTY FUEL INJECTORS WILL CAUSE ENGINE TO ROUGH IDLE OR IDLE UP AND DOWN.PUT A BOTTLE OF FUEL INJECTOR CLEAN IN A FULL TANK OF GAS.ALSO CHANGE PLUGS AND WIRES.IF TRUCK HAS 30000 TO 60000 MILES ON IT.THATS THE SCHEDULE MAINTENCE INTERVALS IF SPARK PLUGS HAS NOT BEEN CHANGED.

code reader would tell you problem, is the engine light on?

Rings & bearings & oil pump need urgent attention!
Cheers Rob

improperly charged or faulty compressor have them recheck it

2 knock sensors are used..small black plastic sensor bolted into engine block below each exhaust manifold..be careful not to over torque bolts upon installation