Welcome to CF !!!

Do you have access to an OBD-II diagnostic scanner?? There are most likely one or more diagnostic trouble codes set in the car's system and, if you can retrieve the codes, use the below link to define and post what you found. Repair shops and parts stores ............... maybe an auto club.

OBDII diagnostics. Trouble codes description for GM

OBDII diagnostics. Trouble codes description for GM

obdii.pro

Diagnostic codes read out as a letter, four digits, maybe a suffix letter.

 

Welcome to CF !!!

Do you have access to an OBD-II diagnostic scanner?? There are most likely one or more diagnostic trouble codes set in the car's system and, if you can retrieve the codes, use the below link to define and post what you found. Repair shops and parts stores ............... maybe an auto club.

Diagnostic codes read out as a letter, four digits, maybe a suffix letter.

I unfortunately do not have a OBD-II diagnostic scanner. I will probably buy one in case this happens again(I hope not)
Thanks

 

The flashing CEL indicates sustained misfire of one or more cylinders. Traction control and Stabilitrak are disabled when the engine is not operating properly because those systems depend upon the engine to respond exactly as commanded in order for those systems to operate.

If you mechanic is a significant distance away, if the flashing CEL continues while the car is in motion then I would strongly advise that you have it towed or put on a flatbed to your mechanic. A flashing CEL is used when a sustained significant misfire is occurring because it is likely that raw fuel is being dumped into the catalytic converters and this will rapidly overheat them resulting in their destruction and it can lead to a vehicle fire because they will soon be glowing yellow hot. If it is ABSOLUTELY necessary to drive it a very few miles with the flashing CEL, do so slowly and at very light throttle application. But that is still a bad idea.

Rodger

 

Thank you for telling me what this means, I will probably have my car towed to the mechanic.
This also happened out of nowhere my car was running fine do you have any idea why this would happen?
Thank you

 

There are lots of possibilities, hopefully a failed coil pack, spark plug, or injector because none of these would be terribly expensive.

Rodger

 

Hopefully one of those, what are some other reasons that would cost me a lot of $$$?
I'm still trying to learn about this car I bought it somewhat recently.
This car is very nice, and it isn't cheap.

 

There are a lot of mechanical things that could happen but do NOT worry about that until you have the car scanned by your mechanic because the odds are extremely high that it is a very simple issue with spark (coil pack or plug) or fuel injection (injector not spraying or not spraying the correct pattern).

The 3.6L had become highly reliable by the time the ATS was introduced, the original generation 3.6L I had in my 2008 CTS is known for timing chain guide wear which was made far worse by GM trying to match BMW's idiotic extreme mileage between oil change interval when they introduced their DI engine. I had a fairly early production 3.6L direct injection but it got its first oil change at 1,000 miles and thereafter was changed at the 60 and 20% OLM indicated intervals at which point I would reset it. If you followed the original OLM calibration, it would allow over 25K between changes under normal conditions which was ridiculous and that OLM set of constants was changed through a recall with new calibration by GM after the engines started eating timing chains early in life. Mine was still fine at 90K when I traded it in for my ATS.

The 3.6L has been one of my favorite GM engines, along with the highly reliable "3800" and the classic 350 V8. Anything can break and break expensively but your odds are very favorable with GM's better engineering efforts and the 3.6L falls in that school. I ordered the current generation 3.6L when I bought a 2021 Camaro after my daughter started driving the ATS. I would have ordered the CT-4 replacement for the ATS IF they had a powertrain choice I liked, if the 3.6 had still been available I would be driving a CT-4 instead.

Shortly after my generation of Corvette was released (I have a 2016 C7 Z06), a bunch of owners freaked out when their nearly brand new vehicles displayed the same symptoms as your car. The assembler wasn't always pushing the spark plug wire caps firmly onto the plugs and many cars with under 1,000 miles were suddenly displaying a flashing CEL for misfire along with shaking and TCS and Stabilitrak systems disabled.

Rodger

 

I'm having the car scanned and hopefully fixed by the mechanic tomorrow morning.

I bought this car used and it had like 110,000km (68,350 miles according to google) on it.
This car is used, the guy who I bought it from (we are friends now) said that he changed all the oils on time. after I bought it, I changed engine oil and the car was in excellent condition, I don't know what you mean by OLM calibration.
Thanks for letting me know about the reliability of this engine, I will keep you updated on what the mechanic tells me.
Thank you for all your help.

 

OLM is the acronym for Oil Life Monitor. It is a system that GM has used for many years and has continuously improved which tracks vehicle operation in order to indicate needed oil changes. It is a very sophisticated system that track multiple aspects of vehicle operation to accurately gauge the impact upon the oil. With your ATS, you can feel safe in trusting what its percentage readout tells you in terms of remaining oil life and when to change it.

With the exception of the early 3.6L second generation CTS application, the OLM system has been excellent and I think that poorly implemented calibration was driven by marketing and not the engineering side of what was then called Powertrain Division because those engineers were first rate.

Hopefully your 3.6L is purring happily again soon!

Rodger

 

Oh, you mean the thing that tells me my oil life, yes, I did follow it and I changed my engine oil when it was reaching the end of its life it's a very helpful system.

Thanks!

 

If a cylinder is misfiring allowing sufficient amounts of raw fuel to pass down to a catalytic converter and the converter is up to operating temperature, it may melt the substrate to the point of plugging up the the exhaust flow. You don't want to go there.

Why can't you have it towed?

 

The CEL was not flashing, the mechanic is also checking the catalytic converters.

as for the towing, I'm do not want to share the reasons, I apologize.

 

Whatever is causing the misfire has mostly abated. I would drive straight to your mechanic at reasonable speed and park it. You may have a coil pack going out which is cheap and no big deal if addressed quickly.

IF the CEL starts flashing again, stop driving it because you will be turning a minor inexpensive problem into one that is very expensive. A flashing CEL means that there is a sustained misfire in one or more cylinders and if the misfire isn't due to lack of fuel (spark, valve, etc.) then there is raw fuel going directly into now hot and quickly getting hotter cats.

If it is a coil pack going out, make sure that the associated plug is also replaced because a bad plug can damage a coil pack.

Rodger

 

The CEL did not flash at all while I'm driving, I arrived at the mechanic, and he said I need to replace the oxygen sensor and spark plugs, I'm going to buy new ones right now and get them replaced. Thankfully you were right it was the spark plugs. The check engine light was on but was not flashing.

The mechanic is also checking the coils and the catalytic converters.

I'm guessing replacing the oxygen sensor would fix my StabiliTrak and Traction Control?

Thank you so much for your help!

 

A 3.6L normally wouldn't need plugs at your mileage, forced induction engines like the 2.0T have a shorter life/required change interval. I suspect you have a coil pack that is failing but it certainly won't hurt to change all of the plugs. Normal suggested life is 156,000km/97,500 miles and that is a "safe" interval where GM felt the chances of plug failure was extremely low. Not every part makes the expected MTBF but I would be very suspicious of the associated coil pack on cylinders with a high misfire count because they are far less reliable than plugs.

The ECM will show misfire counts by cylinder so it will be pretty easy for your mechanic to run down the cylinder(s) with the issue. The coil pack ignition systems used on these vehicles is very good at "firing" even plugs that are far past their prime so I would be very suspicious of the coil pack for any cylinder with a high misfire count unless the plug is obviously damaged (i.e. cracked insulator).

Glad you made it safely to your mechanic!

Rodger

 

I don't know what caused the spark plugs to need replacing, and the mechanic is checking the coils on the cylinders, they probably need replacing according to what you have told me.
I will keep you updated with what happens and what the mechanic says.
Once again thank you so much for your help, I would probably not know what to do.

 

I am sure it will turn out well.

I wouldn't replace all of the coil packs because they aren't a certain number of miles maintenance item. Just replace any that are failing.

Most cars go to the car graveyard with their factory coil packs still in place while others get one or two new packs over their lives but it would be incredibly unusual for a vehicle to have all coil packs fail. And depending upon the quality of the replacement, you could be replacing a functioning high quality OEM pack with a lesser quality aftermarket part.

The ECM retains a history count of misfire by cylinder and a good scan tool will also display misfire counts in real time so it is easy to identify which cylinder(s) cause the flashing CEL. And generally a weak coil pack or problematic plug will have the most trouble firing at high load, high RPM so full throttle acceleration will often cause the guilty party to reveal itself.

Rodger

 

I am sure it will turn out well.

I wouldn't replace all of the coil packs because they aren't a certain number of miles maintenance item. Just replace any that are failing.

Most cars go to the car graveyard with their factory coil packs still in place while others get one or two new packs over their lives but it would be incredibly unusual for a vehicle to have all coil packs fail. And depending upon the quality of the replacement, you could be replacing a functioning high quality OEM pack with a lesser quality aftermarket part.

The ECM retains a history count of misfire by cylinder and a good scan tool will also display misfire counts in real time so it is easy to identify which cylinder(s) cause the flashing CEL. And generally a weak coil pack or problematic plug will have the most trouble firing at high load, high RPM so full throttle acceleration will often cause the guilty party to reveal itself.

Rodger

Maybe I should go to the car graveyard and find a Cadillac with factory coil packs that work and use them as replacements.

I will get the mechanic to use a scan to check the ECM for the history of misfires by cylinder.
I will try the full throttle acceleration thing you are talking about.
Thanks!

 

You are welcome!

Rodger

 

Good to hear, you must have had a really bad plug or two. How many KM/miles are on the car now?

Rodger

 

As of now the car has about 116,000KM (72,079 miles)
One more question, where can I find oxygen sensors online? Here in my country, they are very expensive to get. I'm looking to find some online it would be more cheaper.

 

It might be carbon buildup

 

There is no way a 3.6L that didn't have significant other issues can build up enough carbon in 72,000 miles to create those sort of dramatic symptoms. There is a huge difference between seeing some carbon buildup on the intake valves and having enough buildup to actually cause a minor loss of power much less severe vibration and DTCs being set.

Maybe if it were an early generation BMW GDI engine which had major issues and required multiple cleanings by the time they hit moderate mileage but these engines regularly go over twice this mileage without carbon buildup creating any issues for the owner. GM and other manufacturers learned lessons from the early experiences of some of the other designers.

Rodger

 

The car has been running amazing before this stuff ever happened, I would rip through the streets and race people and the previous owner took good care of the car and from what you said its definitely not carbon buildup.

Also new thing, the car has been running bad and Stabilitrak turns off after 2 or 3 minutes of starting the car and along with the Stabilitrak turning off the CEL flashes for about 5 to 6 seconds I believe but then stops, I turn the car off and turn it back on and Stabilitrak stays on, but I still have a CEL light (NOT flashing)

After that I drive the car and it does not feel good, When I come to a traffic light and hit the brakes right before stopping the car jerks back and like jerks forward and back and I felt something with the transmission I just can't say what exactly.

One last thing, I still have not replaced the oxygen sensors.

 

Very well said and I wouldn’t use those liquids as well

 

I’ve not done it myself, but allegedly the Torque Pro app can read Mode 6 data, and that seems to be the key for what you’re after. Might have an easier time finding a Bluetooth OBD dongle and using the app then getting a scanner, recognizing that you may be limited by what’s available in your country.

 

I had this happen to me today on my ATS 2.0 turbo. Found this post, thankfully! I pulled into the nearest Autozone, bought 4 coilpacks, borrowed a 10mm socket and a torx driver, fixed and running like brand new in 20 minutes. Thank you!!!!!

 

Any update on this issue?

 

My 2013 20.0 ATS just had similar issue. Was at a light waiting to get on highway and noticed rough idle. Got on the highway and couldn’t accelerate past like 40mph. Guess you could explain it as rumbling when tryna accelerate with no power. Stabilitrak came on the dash and I got towed. got it scanned and came back as p0301 cylinder 1 misfire.

Go in the car today almost a week later and no engine light. Drove around and seemed fine(going about 20mph) and when I tried to accelerate over like 35 it started doing the same thing but I let off the gas quick and no engine light came on. Made it home going about 15

 

Well your issue might be the 20 liters of engine you got did you ever find out what was causing the issue?