There has been a lot of discussion regarding the alumnium engine cradle that Chevrolet is using in the new Impalas and Monte Carlos.  A number of these cars have suffered from the dreaded engine cradle pop.  For a number of months, Chevrolet service departments have tried numerous fixes.  Replacement of the cradle, additional welds, grease, and shims.  Chevrolet has come out with a TSB (Technical Service Bulletin) that advises dealers to add shims and grease to the engine cradle.  However, the question is:  has Chevy fixed this problem with the '01 models and what changes, if any do the '01 cradles have as compared to the '00?

Teo was able to take a few photos of a '00 and a '01 engine cradle and was nice enough to send them in.  I have used some of his descriptions to help point out the differences between the two.

  Kevin said he had a hard time visualizing the cradle from the photos.  But he had the Helm manual on hand and that had a sketch of the cradle.  He scanned it in and sent it to me to help others determine which end is which.

This is a photo of a 2000 engine cradle that has been removed from the car.  You can see both rear brackets.  Areas A and B are welded in the 2001 cradle.  The gap between the bracket and the cradle frame itself is clearly evident (A).  Flexing of this assembly is what causes the popping noises.
Here is a closeup shot of a rear bracket on a 2000 engine cradle.  Note no weld in this area.
Here is a closeup shot of the rear bracket from a 2001 engine cradle.  You can see the area with the added welds along the side (arrow).  This will prevent unwanted movement in this and eliminate the popping noise.  This is from a 2001 LS with a build date of 12/00, VIN 242,xxx.
For ease of comparison, look at this photo of the '01 cradle and the photo below of the '00 cradle. This photo is the opposite side of the '01 rear bracket.  Notice the extra weld (A) as compared to point B from the next photo.  I had a hard time visualizing this.  Bolt C in this photo goes into hole D in the next photo.  It also helps to imagine the view you have here is the same view you would have if you were looking at the following photo in the direction of the E arrow.
This photo is of a '00 engine cradle.  It goes along with the above description.
This pic shows the '01 cradle assembly at the front left tire area.  Notice the supporting bolts at the front...the shim material is in between the frame assembly and the supporting bolts.
This shows the '01 cradle assembly near the right front wheel area.
This shows the '01 rear left corner cradle assembly.  Notice the extra welds made at this joint.
I was under the car doing an oil change and I found something interesting.  There is a number laser-engraved on the back of the engine cradle.  This photo is taken with the camera looking foward.  That is the driver's side front tire in the background.
This is a close up of the number.  Is everyone's number the same?  This would mean it is a part number.  If the numbers are different, then it could be a serial number and we can narrow down which cradles are the old version and which ones are the newer version.

Now we can see what changes Chevrolet did to the engine cradle between the 2000 and 2001 model year.  I would be interested to hear from the Monte Carlo owners if there is a change to their engine cradles also.  A huge "Mahalo" (thanks) to Teo for getting these photos!  I thought it was interesting that he got these photos using a Palm digital camera.  I did do a little clean-up, but overall, the quality was a lot better than I expected from the Palm camera attachment.