[Cobawlt2010]

So I own a 2017 second gen Chevy Cruze LT.

This car has 78k on the odometer and I have been having issues with it for about twenty thousand miles so far.

My first issue started around 55k which was a hesitation when hot outside and the car had been heat soaked running on the highway for a while. Once on surface streets after the highway it would stumble on itself on acceleration. I originally chalked this up to the auto start system but noticed it does this even in L6. I then proceeded to believe it was the transmission, so I had it serviced (fluid changed) around 58k. The issue has not gone away since. Further more, after the fluid swap on two lane roads I pass regularly. At random when I go to pass the transmission will attempt to downshift as I go WOT to get around the vehicle in front of me. The transmission will feel as though it is going into a gear it shouldn't be and does not accelerate. The engine RPM's go up but I go nowhere. The shift back down can feel violent if I lift and go back on the throttle right away. It almost feels as though it is spinning up the torque converter rather than the gear it needs to be. No check engine lights which is super frustrating. I plan on lifting the car soon to see if I can see anything. I had the shop who changed the fluid look at the level and they said everything looked fine fluid level wise. This happened right after I got the fluid changed so I assumed it was bad fluid level. Drove all through winter just fine until just a few months ago this issue returned. Any idea or help would be appreciated.

 

[Morsel]

The first thing you should try whenever you have a performance issue with the engine (hesitation in the heat in your case) is to refuel at a different top tier gas station (Exxon, Shell, full list here TOP TIER™ Gasoline Brands). Gas stations occasionally get bad batches.

Your old Ford 300 with 8:1 compression wont care, but these modern engines do.

The transmission behavior is probably the result of the shop overfilling it.

Have the dealership, not some random shop, check the fluid level.
It has to be checked at a specific temperature. If it is not, you can easily overfill it.
Overfilling the transmission as little as half a quart can cause those exact problems.

 

[6Speed2016LT]

Definitely second the top tier premium gas.......Until I knew better I was running regular 87 Octane gas for the first few years....When I switched to Premium 91+ it was an entirely different car. Especially when hot outside.

Jason

 

[jblackburn]

Mine does the heat soak thing in heavy traffic for sure. It is 49593883x more apparent when run on low octane.

 

[Morsel]

Yes, your cars pull timing in response to higher IATs.

If you have another issue thats causing the car to pull even more timing (knock from low quality gas, carbon, etc), you're really gonna notice it.

That's why its important to always check the basics like fuel quality or spark plugs before blaming something mechanical.

Below are some examples of IAT spark correction tables.
These tell the ECM how much advance to add or remove from the final spark advance based on intake air temperature (x axis) and cylinder airmass (basically engine load, on the y axis)
Granted the amount of timing added or pulled according to this table isnt 1:1 - it modulates the values based on engine rpm, humidity, coolant temperature, etc so that its not totally falling on its face in severe operating conditions, but it can still pull quite a bit of timing if everything lines up.

Stock 2011 1.4 cruze:

2010 6.2 camaro:

Its fascinating to see how conservative GM is with these settings.
Granted their higher performance cars (z06 for example) are far more aggressive,
but they start pulling timing on my camaro at 86 degrees Fahrenheit.

Meanwhile Dodge, for example, makes absolutely no changes to spark unless IATs are very high.

 

[Cobawlt2010]

The first thing you should try whenever you have a performance issue with the engine (hesitation in the heat in your case) is to refuel at a different top tier gas station (Exxon, Shell, full list here TOP TIER™ Gasoline Brands). Gas stations occasionally get bad batches.

Your old Ford 300 with 8:1 compression wont care, but these modern engines do.

The transmission behavior is probably the result of the shop overfilling it.

Have the dealership, not some random shop, check the fluid level.
It has to be checked at a specific temperature. If it is not, you can easily overfill it.
Overfilling the transmission as little as half a quart can cause those exact problems.

View attachment 292109
View attachment 292110

1. I always fill up with CITGO, Costco, or Shell. It's usually CITGO though since it's so close to work. Usually 87 or 89. I was told by the dealership there's little point putting premium in it.

2. Trans service was done at a dealership.

The heat soak thing is push on the gas. Get no response until 2-3 seconds after I am on the gas pedal.

I'm not sure what is up with both issues to be honest.

 

[jblackburn]

1. I always fill up with CITGO, Costco, or Shell. It's usually CITGO though since it's so close to work. Usually 87 or 89. I was told by the dealership there's little point putting premium in it.

They tell you that to sell you an economy car. No one wants to buy one that needs something more than 87. The Buick/Cadillac dealer down the road may have customers that would be more accepting of it.

The reality is they benefit greatly from 91+ octane. It's a turbo motor, and turbo motors heat soak and pull the crap out of timing and feel severely down on power to avoid knock.

91+ will also help you avoid piston-cracking LSPI which is quite common in 2017s.

 

[Thebigzeus]

Dealerships sadly aren’t experts on cars.

 

[JLL]

Dealerships sadly aren’t experts on cars.

It all depends on the technicians. Some are ALOT smarter than others.

 

[Morsel]

1. I always fill up with CITGO, Costco, or Shell. It's usually CITGO though since it's so close to work. Usually 87 or 89. I was told by the dealership there's little point putting premium in it.

2. Trans service was done at a dealership.

The heat soak thing is push on the gas. Get no response until 2-3 seconds after I am on the gas pedal.

I'm not sure what is up with both issues to be honest.

Disconnect the battery, wait 3 minutes, and then reconnect the battery.
If its still being dumb, go back to the dealership and tell them you're still experiencing shifting problems.

 

[Cobawlt2010]

They tell you that to sell you an economy car. No one wants to buy one that needs something more than 87. The Buick/Cadillac dealer down the road may have customers that would be more accepting of it.

The reality is they benefit greatly from 91+ octane. It's a turbo motor, and turbo motors heat soak and pull the crap out of timing and feel severely down on power to avoid knock.

91+ will also help you avoid piston-cracking LSPI which is quite common in 2017s.

This was brought up to a technician, not to sales staff. He said 87 is fine. He seemed knowledgeable and he said he was with the dealership for over 30 years. We were on a test drive because of a squeak in certain conditions (something I haven't figured out either but am not super worried about). That happens at high load with low RPM and was worried about LSPI. I do my own oil changes with 5w30 Mobile 1 EP 15k oil (though I think they're now marketing it as 20k oil). I go by the service indicator and change my oil then. I've often thought about using Lucas but considering it isn't Dexos 2 certified I'd rather not. I know it's mostly down to the $$$ for the certification but I'd rather be in spec should something go wrong... though I guess my warranty is up so I shouldn't really care anymore. Either way, I'm fitting the bill at this point.

I have tried high octane and the squeak has not gone away and I noticed no measurable difference in performance of the vehicle.

 

[Cobawlt2010]

Disconnect the battery, wait 3 minutes, and then reconnect the battery.
If its still being dumb, go back to the dealership and tell them you're still experiencing shifting problems.

Was actually planning on doing that this weekend as well as lifting it and checking for fluid leaks...

 

[Morsel]

They tell you that to sell you an economy car. No one wants to buy one that needs something more than 87. The Buick/Cadillac dealer down the road may have customers that would be more accepting of it.

The reality is they benefit greatly from 91+ octane. It's a turbo motor, and turbo motors heat soak and pull the crap out of timing and feel severely down on power to avoid knock.

91+ will also help you avoid piston-cracking LSPI which is quite common in 2017s.

He does not need to rum premium fuel.
Theres more involved to Low speed preignition than just octane rating

 

[Morsel]

This was brought up to a technician, not to sales staff. He said 87 is fine. He seemed knowledgeable and he said he was with the dealership for over 30 years. We were on a test drive because of a squeak in certain conditions (something I haven't figured out either but am not super worried about). That happens at high load with low RPM and was worried about LSPI. I do my own oil changes with 5w30 Mobile 1 EP 15k oil (though I think they're now marketing it as 20k oil). I go by the service indicator and change my oil then. I've often thought about using Lucas but considering it isn't Dexos 2 certified I'd rather not. I know it's mostly down to the $$$ for the certification but I'd rather be in spec should something go wrong... though I guess my warranty is up so I shouldn't really care anymore. Either way, I'm fitting the bill at this point.

Don't use Lucas oil. Continue using the recommended oil, change it when the car tells you to.

GM has active measures to try and avoid "come backs" - they really do want to try and fix whatever problem you're having. If you bring it into the dealer and tell them you're still experiencing shifting issues, they should be giving you a rental and taking however long they need to figure out what's going on.

Here, in a forum where we haven't even seen your car, let alone logged what it was doing, there's not much constructive advice we can give aside from letting you know common problems that cause similar symptoms to what you're experiencing, or maybe some other advise that could help later down the road.

So lets go on a tangent about LSPI! 🙃

You're not hearing knock.
Light spark knock sounds like a can rattling in your cupholder. Its so faint and generic sounding it can be confused with just about anything.
If you look up spark knock on youtube, 90% of the videos are just that.
It is of no concern.

Heavy knock sounds horrible - like this but louder:

But you will never hear this unless you filled up with some ridiculously poor quality fuel or some idiot tuner suppressed GM's knock mitigation strategies.
Your car's knock sensors are set to just about the most sensitive they can realistically be:

In contrast to the previous generation 1.4, where you actually hear light knock at low RPMs:
(raising boost too low without changing these sensitivities is what cracks ringlands on those engines)

Now LSPI (or "super knock", yes researchers really call it that) is a special catastrophic mode of knock that small displacement, direct injected, turbocharged engines are susceptible to. Unlike conventional knock, which is extremely well studied and managed, LSPI occurs randomly following a minor knock event, occurs at a point in the process where the ECM cannot respond to it, and conventional means of suppressing knock (pulling timing and adding fuel) actually make it worse.

This is a graph show the devastating spike in cylinder pressures when LSPI (super knock) occurs:

Current research in preventing its occurrence all come down to combustion chamber design.
The way manufacturers band-aid the problem is to simply not load the engine at low RPMs (you car limits power quite a bit below 3000rpm), and then try to minimize knock as much as possible.
You may have seen oils with a "helps prevent low speed preignition" label on them. Modern oils have been reformulated to help keep blowby from triggering knock events.

This figure explains how particulates present in blow-by gasses and carbon can trigger LSPI:

Before someone says something about catch cans - that wont help you either.

GM now has a turbo 3 cylinder in the new trailblazers that is pretty darn quick, and is rated to pull 1000lbs.
They're figuring out ways around it.

But because you're engine is not their latest design, the best you can do is follow GM's service recommendations, and maybe ask to see if a software update is available.

If the car feels like its starting to cost more than its worth, see how much you can get for a trade-in.

 

[jblackburn]

He does not need to rum premium fuel.
Theres more involved to Low speed preignition than just octane rating

Yes, largely oil too.

The fact remains that power delivery is a lumpy, inconsistent, jittery mess on both Gen 1 and 2 1.4Ts on 87 octane. It is terrible in 70F weather, and it is way worse in 95F weather. Other manufacturers tune better to run on 87, but GM is not one of them.

 

[6Speed2016LT]

91+ Octane and Amsoil, Thank us all later...

 

[Morsel]

Yes, largely oil too.

The fact remains that power delivery is a lumpy, inconsistent, jittery mess on both Gen 1 and 2 1.4Ts on 87 octane. It is terrible in 70F weather, and it is way worse in 95F weather. Other manufacturers tune better to run on 87, but GM is not one of them.

Look, these cars are slow. That's just the way they are. There is nothing wrong with that, but if you're expecting Type R or WRX performance out of this thing, you're gonna be disappointed. Tuning can address quite a bit of the drivability complaints (especially with the older cruzes), but you're not gonna catch up with other sportier cars.

Not trying to talk trash, but its important that we're all on the same page in terms of what is realistically achievable out of this car.

I don't get into my cruze and expect it to respond like my ls3, or the 5.7 I built for a friend's charger PPV.

Having said that:

Yes, I've logged enough of these things to know the engine prefers higher octane fuel. The ECM runs pretty much entirely on knock feedback on 87 octane.

However you are not going to get dramatic increases in performance simply from switching to a higher octane fuel.
If you feel anything at all, you may notice it feel "happier" going up hills.

I also know GM's strategy of blending between two "High" and "Low" octane spark advance tables based on knock feedback, instead of switching between completely different tables like Ford or Honda can set you up for some odd drivability problems (things like "dead spots" in the rev range: car goes, but then hesitates at 2k or something, then starts moving at 3k).

Even so, you car should not act like a "lumpy, inconsistent jittery mess" on 87 octane. Something else is wrong if that is the case.

 

[JLL]

@Morsel , @jblackburn knows that. Most of us on this forum know that. If we would have wanted (or could have afforded) a Type R, or a WRX, we would have bought one.

But, for whatever the reason we bought Cruze's. And for most of us, we enjoyed trying to make our cars better, even if it's not the most economical or reasonable thing to do.

I just wanted to comment because it kinda sounds like you beating a dead horse.

BTW, please make an introduction thread in the new member introduction section so we can get to know you better.

 

[Morsel]

@Morsel , @jblackburn knows that. Most of us on this forum know that. If we would have wanted (or could have afforded) a Type R, or a WRX, we would have bought one.

But, for whatever the reason we bought Cruze's. And for most of us, we enjoyed trying to make our cars better, even if it's not the most economical or reasonable thing to do.

I just wanted to comment because it kinda sounds like you beating a dead horse.

BTW, please make an introduction thread in the new member introduction section so we can get to know you better.

I don't want OP thinking he needs to put $50 oil and expensive gas into his commuter car just to make it drive properly.
Hes clearly not happy with how is car is performing. Moderators telling him to pay more for gas and oil isn't going to make him happier.

 

[JLL]

I don't want OP thinking he needs to put $50 oil and expensive gas into his commuter car just to make it drive properly.
Hes clearly not happy with how is car is performing. Moderators telling him to pay more for gas and oil isn't going to make him happier.

I'm going to take off my moderator hat for a second because I don't want people to think I'm smarter than them just because I'm a moderator. I love my Cruze and I love this forum.

I've worked in the automotive service industry for 10 years. I've owned 3 turbocharged vehicles. I can vouch that a turbocharged engine runs better in the long run using premium fuel and oil vs. Low quality fuel and oil.

But, I agree there could be an underlying issue with the OP's car.