The saga of the p0011

[RET423]

I don't think the VVT will cause a miss on just one bank, I think your in one of those scenarios where the engine diagnostic is pointing you in the wrong direction

I would start looking for the miss with old school diagnostic procedures of fuel, spark & compression to see if you can get rid of the miss; if you fix the miss I suspect the VVT code will also go away

Good luck, I hate chasing these weird ones

 

[Discodisco]

So my PCM to cam sensor signal was fine as was the 5v ref and lo ref. While at a stand still and activating the cmp test the engine will raise to a high idle and command the actuator from 0-50 degrees in 5 degree increments which is did fine. I took the truck out for a spin while watching the commanded advancement of the cam by the PCM vs the actual position and found that unless I was under roughly 50% and up load on the engine I was getting hardly any actuation of the cam, it would command 20% and id get maybe 5%. Under harder acceleration where the oil pressure was raised significantly I would get less of a deviation, 8-10 degrees from commenced to actual. I know that these cam bearings are problematic and that the #2 bearing is what supplies the oil passage to the actuator via the center bar of the cam so I decided to do some roadside science. I stopped at a parts store and picked up that super thick and gooey Lucas additive and added half the bottle. Went back out while monitoring numbers and found that actuator much more responsive at lower rpms while cruising, it dropped the deviation by about half indicating there is indeed oil getting past the bearing. I pulled over and dumped the rest of the bottle in there and drove 5 miles on the freeway and found the actuator WAY more responsive at all rpms. It still did exceed 10 degrees of deviation but only once for more than 10 seconds. ive come to the conclusion the number 2 bearing is not happy and my plan is either vvt delete and a bigger cam or attempting to replace the front 2 cam bearings without removing the engine.

 

[Discodisco]

I don't think the VVT will cause a miss on just one bank, I think your in one of those scenarios where the engine diagnostic is pointing you in the wrong direction

I would start looking for the miss with old school diagnostic procedures of fuel, spark & compression to see if you can get rid of the miss; if you fix the miss I suspect the VVT code will also go away

Good luck, I hate chasing these weird ones

I agree, after my little experiment im thinking I may be losing pressure to the lifters causing the misfire, I think the lifters get their oil via the cam bearing passages.

 

[mikez71]

I don't think the VVT will cause a miss on just one bank...

Probably only a VVT bank 1 code for our engines and no bank 2 code is my guess.

Bummer about it being the bearing, but nice job on the diagnosis and thanks for sharing that info!

 

[Discodisco]

further update. Drove about 40 miles since adding the full bottle of Lucas and havent gotten the code or traction light warnings since. looks like it is a good band aid for the situation.