Vibration Issues in LT too or just Premier?

[NGarstka]

Hi -- we have a 4 month old 2018 Suburban Premier that started having vibration issues after the third suspension warning fix.  It started two weeks into ownership, they replaced a sensor (I think), the light came back on a month later, said it was a software bug, updated the software but did not reset suspension.  Went back in because the truck was bouncing all over the place and they "fixed" it.  Now we have this awful rattle/vibration that you feel in the steering wheel, seat, pedal -- all over.  It never goes away, no matter how smooth the road.  It's been in for service 5 more times as required from GM support.  They found the rear differential wasn't up to spec, replaced bushings and something in the steering.  It's worse now.  This doesn't seem to be the same issue that some have at high speeds -- it's terrible at 20-50mph.  You feel every single pebbled, ridge, bump, whatever.  It's maddening and the car didn't drive this way when we bought it.

 

Anyhow, GM engineers have said that the vibration is within limits and they won't do anything.  We are trying to work with the dealer but no one is willing to eat the loss on a trade.  My question is if an LT would be better or does that model have the same issues?  This is such a frustrating situation after buying a car with an MSRP of $73K.  I thought we had a good case with GM but they are unwilling to even talk anymore and have gotten pretty ugly -- told us we were lucky to get the differential fixed under warranty even though it came from the factory incorrect.  I would never have guessed it would be this bad....

[Ira1976]

Didn't you see the commercial? Chevy is more reliable than Honda and Toyota ?

[O_J_Simpson]

Is this your first GM?

[NGarstka]

Yes, our first -- I've driven at least 5 additional Suburbans in the meantime and none have this issue.  The LT wasn't as smooth on the big bumps but it handled the typical grocery store/school run much better.

[K2xxSteve]

Damn. Sorry to hear about the issues. How many miles? I also just bought a 2018 in the beginning of November. Which sensor? You’re having an issue with the Magnetic Ride suspension? This doesn’t sound like the usual body resonance and shuddering issue that a lot of people have especially with the 22” wheels. This sounds like something quite different.

[NGarstka]

Thanks -- I agree, it doesn't seem like the "shake" issue and it started around 3500 miles and the same time they didn't reset the suspension after the bug fix.  The interesting part is that after fixing the rear differential, bushings, steering I have started having that buffeting issue on the highway.  

Unfortunately they are dumping this into the bulletin for those having the vibration at high speeds and so they say its within the limits.  The master service tech said that that vibration allowance at lower speeds on the magnetic ride indicates that they know it doesn't perform well in the 30-50mph range.  

I'm obviously not a car person so this is tricky.  I called another dealer today and they said they'd give me $53K on a trade -- $20K below MSRP in 4 months.  Ouch.  

Perhaps it would be wise to pay an independent mechanic to take a look and advise.  We are reluctant to modify the suspension in the event it would void the warranty -- it feels like we have a lemon.

 

[K2xxSteve]

Try another dealership service department? Sounds like a load of crap from the first dealership, but not out of the ordinary from what I've heard around these forums. Don't think I'd take it to an indy just yet.

 

Which wheels and tires do you have? 

[K2xxSteve]

16 hours ago, NGarstka said:

It's worse now.  This doesn't seem to be the same issue that some have at high speeds -- it's terrible at 20-50mph.  You feel every single pebbled, ridge, bump, whatever.  It's maddening and the car didn't drive this way when we bought it.

By the way, this right here almost makes me think that they put a sensor in reverse or somehow reversed a wiring harness if that's even possible, hence the totally bizarre behavior that's the complete opposite of what you'd expect, and not being able to "fix" it or the problems just getting worse. Even odds that the dealership f*cked something up that they're not fessing up to. Definitely take it to another dealership, or if you can find one, a legit independent shop that knows how to work on these trucks and is familiar with GM's Magnetic Ride system and have them look it over for something like this. Magnetic ride is supposed to adjust so that you don't feel that stuff, but what you describe almost sounds like it's amplifying it instead, which is what could happen if something is reversed!!! Would be totally bizarre and truly rare, but I know it can happen (not specifically on these trucks, but in general.)

[The Zip]

On 1/25/2019 at 7:52 AM, S P said:

Try another dealership service department?

That's not normal any way you cut it, he just has a lemon.  His VIN is in the GM database, going to another dealership is not going to help especially since GM said his vibration is within limits.  As for the original question "vibration issues in LT too or just Premier", similar issues are in both but not all.  Yeah he may lose 20K, but getting 53K may be a better deal than letting an independent shop look at it.  Once an independent shop disassemble components, the value goes way down if I'm a dealer.  Unfortunate because if it's traded in, that dealer will boost the price back to the 70K range and we'll see the new buyer on this forum.

[NGarstka]

Hi 

 

Just wanted to follow up since you all took the time to respond to our issue...after many weeks at the second dealership's service department, GM sent out their engineers and pretty much closed the door on us.  We posted a negative review on Facebook and within a day the original dealer had convinced GM to offset a trade.  We ended up with a 2019 LT with almost all the same features (sticker was about $3K less) and they gave us an even trade for the 2018 premier with 6500 miles -- it felt like a win.  

 

 

[K2xxSteve]

Glad it worked out!