No I have never seen this type complaint and I have lots of experience on that model.I had one strange intermittent northstar misfire that ended up being very small pieces of the plastic intake manifold coming apart inside the intake plenum hanging up the valves.That one ended up costing me an engine.Here is the only TSB related to your problem.
PI01748A: 4.6L LD8 , L37 and 4.0L , L47 Engine Rough Idle - kw body calibration camshaft code DTC EGR intake leak lean manifold MIL miss misfire PCM - (Feb 20, 2004)
|Subject:||4.6L LD8, L37 and 4.0L, L47 Engine Rough Idle|
When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.
Some 2000 and early built 2001 model year Cadillac Deville, Eldorado, Seville with 4.6L (LD8, L37) engines or 2001 Oldsmobile Aurora with 4.0L (L47) engine, may exhibit a condition of rough idle with no PCM DTC and no driveability complaints
The camshafts must be replaced (part numbers are listed below) on all 2000 vehicles with 4.6L (LD8) (L37) Engines and the early built 2001 vehicles (see broadcast codes listed below) with 4.0L (L47) OR 4.6L (LD8) (L37) Engines. For a 2001 vehicle, you must verify that it has the early cam profile by reading the 3 alpha characters of the broadcast code listed on the tag attached to the passengers side of the engine's rear cam cover. The Broadcast Codes for early 2001 engines are:
Seville, Deville Applications:
ENGINE VIN CODE Y KMA
ENGINE VIN CODE 9 KKA
ENGINE VIN CODE Y KCA
ENGINE VIN CODE 9 KBA
ENGINE VIN CODE C KYA
Camshaft Service Part Numbers:
4.6L (LD8) VIN CODE Y AND 4.0L (L47) VIN CODE C CAMSHAFT SERVICE PART NUMBERS;
12570331 RH EXH
12570332 LH INT
12570333 RH INT
12570334 LH EXH
4.6 (L37) VIN CODE 9 CAMSHAFT SERVICE PART NUMBERS;
12570335 RH INT
12570336 LH INT
12570337 RH EXH
12570338 LH EXH
NOTE: the Camshaft Service Part Number information can also be found on page 7 of the July 2001 GM Tech Link Volume, No. 7
SPECIAL NOTE: If you are having difficulty setting the mechanical timing on the rear bank exhaust camshaft. SI and the Service Manual instructs you to set the exhaust camshaft gear so that the stamping "RE" is in the 12 o' clock position. It has been found the "RE" stamping is located in the incorrect position on the exhaust camshaft gear. The correct positioning of the Exhaust Camshaft is when the camshaft dowel pin is in the 12 o' clock position. and the Exhaust Camshaft gear "RE" stamping is in the 9 o' clock position .
Once all 4 camshafts have been installed, the calibration must be updated. The dealer must contact TECHLINE and tell them that the camshafts on the vehicle have been replaced, and they will give the Dealer a VCI number to install the correct calibration. Techline must be contacted each time so that they have a record of when a camshaft change occurred on each vehicle. This will ensure that future calibration for that vehicle will be correct.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.
(00 01 CADILLAC DEVILLE, SEVILLE, KB, ELDORADO, EB, 4.6L (LD8 , L37) ENGINE) and 01 OLDSMOBILE AURORA 4.0L (L47) ENGINE)