Rick35

Its been several years and a lot of aggravation since my last post. I wanted to add a conclusion that I finally fixed the problem. As someone suggested way back in the posts I added a disabler and the problem is gone. My gas mileage is a little less but I don't feel the shudder as the engine stays in V6 all the time. I should have done this a long time ago!

I first noticed the shudder around 11,000 miles so I don't if it is related to a break in period. I got an oil change at a different dealer last week and I asked the service guy if he knew anything different about the issue. He confirmed that GM considers this to be normal. He knows all too well as he has the same model and the same problem I do.

The service manager said GM considers the condition to be normal. That is a bunch of crap. I'm going to try another dealer but I'm not hopeful.

I have had discussions with my service people a couple of times about possible engine problems and they really believe the issue is in the exhaust. I was in getting an oil change on Friday and told them I wanted to start replacing parts. I want to start with the exhaust and maybe end up with the engine. They can't fix the problem but they want me to believe its not the engine or that the shudder isn't causing engine wear. I'm not buying it. Priority is vacation and I'll reconnect with them when I return.

And I should add that the service writer I deal with says that I'm the only one of his customers with this issue.

Its been a few months since my last post and I wanted to let people know that my shudder problem is worse. Its especially noticeable around 35mph but I also get it at highway speeds. I'm heading back to the shop to see if there any new ideas about fixing the shudder. Since GM didn't offer enough money to help a trade I'm going to recommend that they start replacing parts starting with the exhaust system. The service manager mentioned it early on and I didn't take him up on the idea.

GM offered $5000 trade-in assistance to be used on a new purchase. I had to make a deal with sales including the tradein of my 2014 Silverado. They didnt offer me enough to make it worthwhile. If I did buy a new truck I would have had to take out a new loan which would mean an extension of 18 months which equates to about $9000. And that included the trade in assistance. On top of that I didnt want an 8 cylider and looked at a Colorado. I traded in a Colorado and forgot how small it was. And there were no deals. So I decided I liked my truck more than the other options and decided to keep it.

I talked to GM today. First I received an email saying that my email was received and I would hear from a senior advisor within 24 hours and then I received a call late this afternoon. Most of the discussion was about me explaining what the problem was and ended with the advisor asking me what I wanted to do. I added that I was not the only one to experience the problem based on exchanges with other owners (on this forum) and this should not be a surprise for GM. The advisor was going to have a discussion with the dealership and we're going to talk again later this week.

Its been a few weeks since my last posting and I figured I needed to provide an update. My vibration/shudder issue still exists although it is slightly better. I scheduled another appointment with my dealer thinking they could add another dampener. Service called and told me the one dampener is the only fix for the problem so I cancelled the appointment and asked for guidance in how to initiate a buy-back. The guidance received was an 800 number. I found a GM warrranty/lemon web page and sent an email to GM and am waiting for a reply. There are a number of concerns or unknowns about this condition with few facts: 1. V4 to V6 shudder appears to be unique to 4.6L engine. I could not find any posts where the issue occurs on V8's. 2. Bulletin from Oct 2014 talks to AFM vibration issue and addresses exhaust mounts and bolts 3. Exhaust vibration has been happening for years on many vehicles and various dampeners have been used to counteract vibration and to reduce noise. 4. Dampener used in my situation was employed two years after model year was introduced. It was described as a new fix for the problem. Why now? It took two years to come up with a resolution (that doesn't work)? 5. My issue surfaced at 10-11,000 miles - no issue prior to then. Why now? 6. There is no information on what is causing the issue although GM is holding to its vibration dampening solution. My issue is that I don't know what is going on in the engine. My plan was to run the truck for ten years and now I don't know if that will be possible. I don't know what I'm experiencing is causing any damage to the engine and I believe I need to get out of the vehicle now while it is in otherwise great condition. Hopefully GM will help me do it.

I've had a chance to do some straight highway driving this weekend and unfortunately some of the shudder still exists. I think I notice it now because the road is smooth and also because I'm looking for it. If I didn't know it was a problem I don't know if it would bother me. I need to talk to service on Monday as a follow up and will see what they think. I may have to live with it. But it is much better. Maybe I'll hook a small bungie onto the clamp and see if that helps. It may help put a little tension on the pipe to take up what vibration remains.

Thanks to everyone who shared their experiences. Hopefully this can now help you get your trucks running smoothly.

It worked! Now that you see this thing you could do it yourself with a few scraped knuckles. If you could get the part, that is.

I tried again and found a brown cylindrical object attached to the exhaust in front of the catalytic converter. After not finding anything earlier I went back into the house and googled dampener again and I found a photo of an exhaust dampener from a few years ago. Mine looks just like it. From what I found from the old post it sounds like there's weight in the cylinder that dampens the vibration of the exhaust. The service order I received from the field engineer correctly called it a dampener and not a damper which is something different altogether. I'm new to the forum and certainly new to uploading photos and hopefully the photo loads correctly. [

I crawled under the truck tonight and can't find anything new. The adaptive valve is looking original and that's what I thought was the culprit. There was a rubber mount that looked kind of new but I don't know if thats what they call a damper. All I know is that I'm not feeling the shudder.