I am experiencing a rough idle in Drive like some other posts have mentioned in my Yukon Denali (145k miles). No CEL or DTCs whatsoever and it runs very solid other than when at a stop in Drive. It feels like a miss and is 95% gone in P, N, R. You really feel it in the driver seat and can see the tach move. It doesn't feel cyclical, mostly random. Here is what I've done so far:
AFM has been disabled with Range for a long time
I opened valve covers and all rockers are solid and nothing is loose in there
No lifter noise and no valve noise
changed plugs/wires
cleaned throttle body, did reset procedure
cleaned MAF
tested MAP sensor
tested all coils
tested 02 sensors
STFT/LTFT look good to me
no vacuum leaks detected with smoke test
tried e85/premium - no difference
ran 2 cans of berryman b12 through - no difference
checked fuel pressures - all look good
tested all injectors with test tool - all showed same results so I assume no issues
Other threads and forums suggest engine mounts, but it is hard for me to believe that is the problem (maybe ignorance). The engine doesn't move much at all shifting through the gears at a stop (P, N, D) or revving in P.
Could it still be bad mounts even though everything looks solid? My other thought is maybe the Torque Converter. Maybe something is slightly warped and it grabs a bit at a stop? Transmission runs at a good temp, hardly ever gets up to 160 unless it's 90F and I'm in traffic. The transmission shifts very smooth, aside from the occasional coast to power clunk. Don't notice any slipping.
Other ideas/suggestions or how to better test the mounts or torque converter would be much appreciated! I hate to do more work and throw more money at it until I have a better idea of what the problem is. Thanks!
AFM has been disabled with Range for a long time
I opened valve covers and all rockers are solid and nothing is loose in there
No lifter noise and no valve noise
changed plugs/wires
cleaned throttle body, did reset procedure
cleaned MAF
tested MAP sensor
tested all coils
tested 02 sensors
STFT/LTFT look good to me
no vacuum leaks detected with smoke test
tried e85/premium - no difference
ran 2 cans of berryman b12 through - no difference
checked fuel pressures - all look good
tested all injectors with test tool - all showed same results so I assume no issues
Other threads and forums suggest engine mounts, but it is hard for me to believe that is the problem (maybe ignorance). The engine doesn't move much at all shifting through the gears at a stop (P, N, D) or revving in P.
Could it still be bad mounts even though everything looks solid? My other thought is maybe the Torque Converter. Maybe something is slightly warped and it grabs a bit at a stop? Transmission runs at a good temp, hardly ever gets up to 160 unless it's 90F and I'm in traffic. The transmission shifts very smooth, aside from the occasional coast to power clunk. Don't notice any slipping.
Other ideas/suggestions or how to better test the mounts or torque converter would be much appreciated! I hate to do more work and throw more money at it until I have a better idea of what the problem is. Thanks!
