[legendary70]

Hello all.

2017 Camaro.

I am going to try and explain the issue the best i can.

According to a guy at autozone who also is the mechanic for the local police dept said it is a known issue because of the fuel system in these cars.

When we are on the highway or some sort of a long stretch whether its 1 mile or 50 the car seems to make a sound like its reving up and down and it shakes a bit. Hard to explain.

We need to either let go a bit off the gas to press it for it to go and then it comes right back. Does not do it on stop and go traffic.

Any ideas?

Thx

[jd2021]

What transmission do you have? If you have an 8 speed automatic, sounds like its a transmission shudder issue. I have never heard of anyone having fuel system issues like you're describing.

[Need4Camaro]

Not sure what the issue but thats definitely not normal. The fuel system in these cars are very strong for factory fuel systems.

Does it sound or feel like its misfiring and sputtering?
Do you have any shuddering?
How long has it been doing this?

My car never did what you described and I have a 2017 as well. I have had the infamous torque convert shudder and slipping torque converter. You 'may' have a slipping converter if its an auto. Those were known issues for 16 thru 18 models.

[Evergreen6]

Automatic trans?

Some people say they can't feel AFM/DFM in GM's modern V8's. I could feel it all the time in a 5.3 Silverado I had when driving on the freeway. These cars have AFM, yes?

[legendary70]

Its more of a sputtering than a misfire. Its been doing it for about 4 months on an off. Automatic and yes I think its an 8 speed.

only on long stretches.

[WhiteMale]

Sounds like the A8 shudder. There is at least a service bulletin out for dealers on that and a very long thread here on the forum.

[scott_0]

must be just your car, or an automatic thing, my 2018 1le is dead smooth under those circumstances...

[Bumbleboy92]

Originally Posted by Evergreen6

Automatic trans?

Some people say they can't feel AFM/DFM in GM's modern V8's. I could feel it all the time in a 5.3 Silverado I had when driving on the freeway. These cars have AFM, yes?

The newer version that the C8 vette’s and trucks have (DFM) maybe but for us with AFM I can definitely tell when it’s switched from v8 to v4 mode on the highway at least

Originally Posted by WhiteMale

Sounds like the A8 shudder. There is at least a service bulletin out for dealers on that and a very long thread here on the forum.

https://static.nhtsa.gov/odi/tsbs/20...63890-9999.pdf

Essentially, flush the transmission through the dealer and if it comes back replace the torque converter

Originally Posted by jamala00

Sounds like the AFM. I have never personally felt it in my car, but given when it's happening to you, that seems like a likely culprit. Can't you turn the AFM off? I thought there was a tool to do that via OBD. (If I recall Lethal has a video on it.). I guess you could try that and see if it still happens... If it does then it's probably the A8 Shutter.

There’s Range AFM OBD devices to deactivate AFM, a tune works too if by chance you are

Originally Posted by scott_0

must be just your car, or an automatic thing, my 2018 1le is dead smooth under those circumstances...

It’s an A8 thing if not treated it’ll develop the shudder, M6 didn’t have the issue and A10 doesn’t either

To OP, my 2016 had the shudder. I paid for the transmission flush (~$300) since I was out of powertrain warranty. Unfortunately after about a year the shudder returned, I then had AFM turned off in a tune and didn’t have any shudder issues for the following years

[ctrlz]

Originally Posted by legendary70

According to a guy at autozone who also is the mechanic for the local police dept said it is a known issue because of the fuel system in these cars.

When we are on the highway or some sort of a long stretch whether its 1 mile or 50 the car seems to make a sound like its reving up and down and it shakes a bit. Hard to explain.

Could be several things. agree with others here, some combination of torque converter shudder and AFM going in-and-out seems most likely.

I will assume your autozone friend is referring to the AFM system, which is used across many GM vehicles. Many people are sensitive to its behavior and find it annoying.

"revving" changes you should be able to see on the tachometer when you hear them. If the tach doesn't move, the noise is not revving.

It might be worth having your autozone contact hook up a scan tool to see if there are any pending codes.

[dmcmahan60]

It is the shudder issue. If you have driven it a long time while it has done this there is a chance the torque convertor was damaged also. I would get it flushed with the proper fluid and go from there. Good information from others stated in here also

[legendary70]

Thank you all. I will look into al of this.

Would any of these issues give a check engine light?

I sometimes get a check engine but only for the thermostat and when it does the ac don work unless i reset the battery.

[ctrlz]

Originally Posted by legendary70

I sometimes get a check engine but only for the thermostat and when it does the ac don work unless i reset the battery.

I think you should get the thermostat replaced if that is a known problem. it is apparently not that big of a job on the V8.
The AFM system only works when car is fully warmed. If the car detects a thermostat problem, and you get the symptoms you describe, it is probably not AFM.

[Bumbleboy92]

Originally Posted by legendary70

Thank you all. I will look into al of this.

Would any of these issues give a check engine light?

I sometimes get a check engine but only for the thermostat and when it does the ac don work unless i reset the battery.

No check engine light for the shudder, that’s a seperate issue where the thermostat should be replaced. I also had the same issue but kept going for years with just resetting the battery without issue

[Jimmy'18]

Originally Posted by legendary70

Hello all.

2017 Camaro.

I am going to try and explain the issue the best i can.

According to a guy at autozone who also is the mechanic for the local police dept said it is a known issue because of the fuel system in these cars.

When we are on the highway or some sort of a long stretch whether its 1 mile or 50 the car seems to make a sound like its reving up and down and it shakes a bit. Hard to explain.

We need to either let go a bit off the gas to press it for it to go and then it comes right back. Does not do it on stop and go traffic.

Any ideas?

Thx

Sounds like my '18 behaved at around 3k miles on the clock. It was only on the highway going a steady speed and either lightly increasing throttle, or holding a steady speed (like cruise control) and climbing a slight hill. When you let off the gas, the torque converter will unlock and it feels fine until it locks up again in 3 seconds or so when the throttle is returned to cruising speed. The converter won't lock driving around town.

Being that yours is a 2017, if you've never had the updated Mobil 1 tranny flush, I can almost guarantee this is your problem. The factory-fill Mobil 1 (if I remember correctly) supposedly absorbs moisture on its own over time and causes slippage of the converter lock up - which feels like an engine miss or tiny rumble strips on the road. The rpm change is likely from clutch slippage.

Thanks to this site, I knew what was going on and had it flushed and it went away permanently. This was over 4 years ago.