[Alexmdz]

Hey guys I just bought a 2008 CTS v6 and I've had it for 2 months has had an oil change by a certified Cadillac dealership and upon inspection they didn't find anything wrong with it 2 weeks ago.

Now this week everytime I'm in the highway and about to hit 60mph the engine stutters so I have to let go of the gas for a bit and then accelerate again 2x before I can continue to speed up... It does this @58-61 miles per hour ALWAYS.

Any ideas what it could be? The car has 130k miles.

 

[kkuz]

It might be everything... No error codes? I would advice to connect laptop with software like ScanXL and record all readings thru odb2 interface and reproduce the problem. Maybe you will see some misfires or fuel problems.

 

[wcthunder]

When was the last time you had your throttle body and plate cleaned?

 

[snofun3]

When was the last time you had your throttle body and plate cleaned?

He's had it 2 months :helpless:

 

[Alexmdz]

Yes I've had it two months and the only thing I've done to it was an oil change. And this happens every time I'm about to hit 60mph. At every other speed this doesn't occur.
Could it be it needs a tune up?
Bad gas problems? When I got it I was switching between plus and premium but only from shell gas station no other gas station. I've ran out all the gas and used a gunk remover in the tank and then filled it and it still occurs.
Could it be cold weather? Its -6 degrees but it does it when the car is warmed up too... I'm out of ideas. Thanks for all input.

 

[Kevin2050]

New plugs and have the throttle body cleaned.

 

[EVH5150]

I'd bet almost 100% coils. One or more faulty coils will definitely cause a stumble. Other members on this forum have fixed this issue by replacing the faulty coil or all of them.

Hey guys I just bought a 2008 CTS v6 and I've had it for 2 months has had an oil change by a certified Cadillac dealership and upon inspection they didn't find anything wrong with it 2 weeks ago.

Now this week everytime I'm in the highway and about to hit 60mph the engine stutters so I have to let go of the gas for a bit and then accelerate again 2x before I can continue to speed up... It does this @58-61 miles per hour ALWAYS.

Any ideas what it could be? The car has 130k miles.

 

[Alexmdz]

I'd bet almost 100% coils. One or more faulty coils will definitely cause a stumble. Other members on this forum have fixed this issue by replacing the faulty coil or all of them.

Thanks Im taking it today to the dealer and hopefully that's all it is. I have a 1 year warranty off the dealer so hopefully it covers it.

 

[JCBCTS]

Weird that it is a speed and not an RPM that triggers the issue...does this occur at 58-61 no matter what gear you are in...ie. does it happen under hard acceleration AND gradual acceleration?

 

[Alexmdz]

Weird that it is a speed and not an RPM that triggers the issue...does this occur at 58-61 no matter what gear you are in...ie. does it happen under hard acceleration AND gradual acceleration?

Yes it starts happening at 58 mph whether I'm accelerating fast or slowing hitting that speed

 

[JCBCTS]

OK my uneducated guess is that it is ECM related and somehow the speed limiter is trying to kick in. The wouldn't think the engine would "care" how fast you were going to present a misfire - seems that would be correlated with RPM. Please let us know how it comes out....good luck that it isn't too expensive!

 

[tinman]

Weird that it is a speed and not an RPM that triggers the issue...does this occur at 58-61 no matter what gear you are in...ie. does it happen under hard acceleration AND gradual acceleration?

Maybe try putting it in, say, 4th gear and go to the 58-61 mph and see if it occurs at that speed IN 4TH GEAR. Then try again in 5th gear at same speed. This will tell you if it is a MPH or RPM situation.

 

[Alexmdz]

Maybe try putting it in, say, 4th gear and go to the 58-61 mph and see if it occurs at that speed IN 4TH GEAR. Then try again in 5th gear at same speed. This will tell you if it is a MPH or RPM situation.

OK gonna try that today in the expressway see how it reacts....
Had an odb scan and no error occurred.

 

[wcthunder]

He's had it 2 months :helpless:

oops. LOL. Let me ask you a different way. Do you have service records? WHEN was the last time IT had a throttle body & plate cleaned? or a tune-up for that matter...

 

[tinman]

wcthunder, you've been inside too long. They have to let you out every once and again for you mental health.

 

[Alexmdz]

Quick update finally had the time to do it... I had cylinder 6 failure code on the obd replaced ALL 6 spark plugs it fixed the error and the CTS actually runs better than when I got it, can actually feel the horsepower

 

[Backinblack11]

What plugs did you replace them with ? Did you do it yourself ? My car is coming up on 100k miles and I feel it stumble when sitting at a red light. Its not constant. Plus when I really get on it it feels like it pulls in waves and not a strong, smooth power so I plan on a throttle body clean first but I imagine plugs and wires would be next. Did these cars come with the 100,000 mile plugs from the factory like most cars do nowadays ? Fuel economy on mixed driving is 17mpg and I also was under the impression it was 18 city and I cant even get close to that even with over half the miles on my last tank being highway at about 70-75 mph

 

[Acdcpsp]

He's had it 2 months :helpless:

Friend of mine bought an Acrua TL with 120k miles which 10k less miles then OP CTS. After 2 weeks the transmission went. Then 4 months later various sensors went and it developed tons of electrical problems. Now the car sits and he car pools. I guess Cadillac's aren't too bad.....