[SomanXL]

Hi all! I am happy to join this community

I am a 2016 CTS-V owner from Germany, so please excuse my english.

Since a couple of month I am facing some issues with my CTS-V and I wonder if anybody else has ever had the same problems and probably knows a solution.

When I am driving the car in the normal automatic mode and the engine is getting to normal temperature (Oil >80 °C) it normally does switch to V4 when I am driving relatively slow and in high gears. But it runs so badly on V4.. i have vibrations, strange noises and overall no smooth driving. When I speed up a little and it goes back to V8 its much better. Howevery, as soon as the car was on V4 once, it will never drive smoothly again. Even in V8 at low rpm and 8th gear I get vibrations frequently (every 20 seconds or so, for like 3 seconds) it feels like driving on some bumby marks on the road and then its gone again, but comes back after some seconds.
To avoid this, when I start the car and the engine is still cold, I can switch to manual mode. Then it never goes into V4 mode and the car runs smoothly all the time. But when I hit it very hard with fast accelerations and the engine gets hot, the vibrations can occur again. Overall its kinda frustrating because its impossible to drive the car in automatic mode, and its embarissing driving such a nice and expensive car and it vibrates like a cheap old car. And even in manual mode its not completely smooth, especially after using the full power of the engine. My feeling is, that the problem is somehow software based? because with V4 it comes immedeately. But I am not an expert, so I hope you could help me with that issue?

The car is completely stock.

Kind regards

Mathias

 

[RobF300]

You seem to be out of warranty so why not get it tuned out

 

[SomanXL]

Hi Rob,

Yes, that would be exactly what I am up to. I just wanted to be sure its not a mechanical problem or so. I found another thread where exactly the same problem is described. They say a trans fluid flush might help. I will try it and do the tune out anyway.
Thanks so much

 

[PGA2B]

If you go to get it tuned they can also advise if they feel it is mechanical or tune related.

 

[iviaillet]

Hi Rob,

Yes, that would be exactly what I am up to. I just wanted to be sure its not a mechanical problem or so. I found another thread where exactly the same problem is described. They say a trans fluid flush might help. I will try it and do the tune out anyway.
Thanks so much

My 2015 Sierra suffered from a similar issue, felt like it was going over a bumpy road, it has the 8 speed but I would always keep the truck in 7th to prevent cylinder deactivation. The bumpy feeling happened in every gear around 1700rpms. The dealer replaced the transmission fluid with Mobil 1 synthetic LV ATF HP and it fixed the issue. The only difference from your issue is that it had nothing to do with the cylinder deactivation. Try preventing the cylinder deactivation and see if you still have the issue.

 

[dougyfd]

On the Corvette c7 sites they mention a range device that prevents engine from going into v4 mode. Not sure if they make one for cts v but they may since it's basically the same engine.

 

[papi]

Sounds like you're talking about trans shudder. Common problem with the 8 speed trans.
Search the forum, there are a couple threads with good info on this.

 

[cefko2011]

Hi Mathias, it is the Shudder Problem. So you must change the Gearbox Oil with Mobil 1 Synthetic LV ATF HP
You can send me a PM if you want, I`m from Liechtenstein (close to Austria and Switzerland), and we can talk German.

Marco

 

[Nighthawk111]

Another vote for trans shudder. It feels like an engine problem like misfires. There is a TSB so you should be able to get a dealer to complete the fluid change under drivetrain warranty.

 

[cefko2011]

Another vote for trans shudder. It feels like an engine problem like misfires. There is a TSB so you should be able to get a dealer to complete the fluid change under drivetrain warranty.

....no chance, it is a 2016, no warranty

 

[dougyfd]

They still might do it as a goodwill gesture for this common shudder issue

 

[cefko2011]

They still might do it as a goodwill gesture for this common shudder issue

.........Shudder Problem come back after 40.000 KM, and I ask Cadillac Europe. They answered me the CTS is out of Warranty.........

 

[SomanXL]

Meanwhile I have the oil, the filter and the gasket at home. I´ll keep you posted how it runs after the trans fluid exchange.