Engine shudder under acceleration when cold

Good morning,

It could be carbon build up on the intake valves that would cause misfire when cold and runs fine when warm. Top engine cleaning will help break up that carbon on the face of the intake valves.

Did the camshaft sensor replacement resolve the check engine light? That is a common failed sensor due to its location.

Another possibility is the transmission causing the shutter.

What transmission? the 8.1 usually uses the Allison Transmission.

Roy

Pulled the camshaft position sensor (#12575172) today, will order new part and replace. Transmission is 4L80E.
Thanks.

Okay, replace that and see.

As far as the shutter, the torque converter clutch can cause a shutter. the clutches inside are common for this issue. There is an additive at a parts store for torque converter shutter. you just add it to the fluid and drive it. it takes about ten miles to work in. this will tell you if that is the case. if the shutter stops then the torque converter is the issue. it will have to be replaced if that is the case.

Roy

Replaced camshaft position sensor, cleared code, everything is perfect - NO shudder on acceleration on 'cold' engine! Thanks, Al

So the new sensor was no good???

Roy

I was letting you know your suggestion worked by installing NEW sensor. Thanks No more problems or codes.