Mustang Evolution Forum banner
1 - 11 of 11 Posts

·
Registered
Mustang GT 2017
Joined
·
3 Posts
Discussion Starter · #1 ·
Hi, I have a 2017 Mustang GT, and I currently have some high knock activity WOT, so right after stepping on it, I get 7+ on the knock sensor, sometimes 4, 6, and the highest 9. I honestly don't think that it's a false knock. I was trying a tune that was sent to me. However, I could not continue with the revision till I fix the Issue. My car has the stock tune currently and I still have the knock activity. I've already filled the car four times with 91 octane fuel from Costco or Shell, Cleaned the air filter, replaced sparkplugs, and tried to see if I saw something rattling in the car. I will try to load a few data logs that I have to see If I can get any recommendations, Thanks in advance!

The car is completely stock other than a K&N Air Intake and some Borla muffler tips.

I won't let me share Csv Files but here's the link to google drive if someone wants to look at them.

(Stock Tune)

Rectangle Font Parallel Screenshot Pattern



(Custom Tune from a tuner)

Rectangle Font Parallel Pattern Number
 

·
Administrator
Joined
·
1,433 Posts
Welcome and thank you for joining MustangEvolution!
Please read the Site Rules if you haven’t already.
I encourage you to complete your Account Settings.
If you need help posting? Please read this FAQ.

We’re happy you’ve chosen to join our community.
 

·
Tech Advisor
Joined
·
56 Posts
There is a couple of things I would look at...1) assuming you have 100k miles, check the cylinders for carbon buildup.....a cheapo cell phone camera will work just fine for this..... a little is ok and normal butt alot will cause detonation....if you have this, not a biggies..... just run the engine at about 2000 rpm and with a spray bottle/fine mist, apply water into the intake... not enough to kill the engine but just a mist... this will take a bit of time but this will clean the carbon off. 2) look carefully at the quality of fuel...a little bit of moisture in the fuel will cause this as well.
 
  • Like
Reactions: crjackson

·
Registered
BLK. 2007 Mustang GT. Premium.
Joined
·
3 Posts
I agree with Beechkid, when you switched between Costco and Shell, did you empty one gas before trying the other gas, if you did, how did they compare? If you didn't them some bad gas could have mixed with new gas. I think you just have some bad gas in your car. Run that all the way down, then go to a different shop, stick with 93 or 91 octanes.
 

·
Registered
Joined
·
5 Posts
I've had similar problems in the past on a Corvette with a 2 piece flywheel like the Mustang. I'd get large knock timing-pull right after a shift. I was the 2 piece flywheel banging against its stops fooling the knock sensors into interpreting the vibration as knock. Knock sensors are filtered to pick up knock frequencies but a banging flywheel can fool them.
 

·
Registered
Mustang GT 2017
Joined
·
3 Posts
Discussion Starter · #7 ·
Welcome and thank you for joining MustangEvolution!
Please read the Site Rules if you haven’t already.
I encourage you to complete your Account Settings.
If you need help posting? Please read this FAQ.

We’re happy you’ve chosen to join our community.
There is a couple of things I would look at...1) assuming you have 100k miles, check the cylinders for carbon buildup.....a cheapo cell phone camera will work just fine for this..... a little is ok and normal butt alot will cause detonation....if you have this, not a biggies..... just run the engine at about 2000 rpm and with a spray bottle/fine mist, apply water into the intake... not enough to kill the engine but just a mist... this will take a bit of time but this will clean the carbon off. 2) look carefully at the quality of fuel...a little bit of moisture in the fuel will cause this as well.
I agree with Beechkid, when you switched between Costco and Shell, did you empty one gas before trying the other gas, if you did, how did they compare? If you didn't them some bad gas could have mixed with new gas. I think you just have some bad gas in your car. Run that all the way down, then go to a different shop, stick with 93 or 91 octanes.
I think you should only use 93 octane fuel. My 2013 runs so much better and puts more power to the pavement with
a stock tune and 93 octane.
I've had similar problems in the past on a Corvette with a 2 piece flywheel like the Mustang. I'd get large knock timing-pull right after a shift. I was the 2 piece flywheel banging against its stops fooling the knock sensors into interpreting the vibration as knock. Knock sensors are filtered to pick up knock frequencies but a banging flywheel can fool them.
Quick update I've filled few the tank a few times from Costco with the 91-grade fuel, so honestly, I don't think that is the fuel. The car has only 65k miles, and I don't have a camera to check for carbon build-up. But I used the redline fuel system cleaner just to try it and see if that was the case. I added it to an almost empty tank, Used all the gas, and refilled again with 91. I've added a PVC breather filter just for a test, and I'm installing an oil catch can just take care of the car. Reran the car with a tune from Ortiz Performance, and I still see a maximum value of 4.80 on the knock activity. Without the tune it only goes around 2 to 3. When should I worry? What would be a regular knock activity for the 5.0, if any?

I also took the car to a performance shop and paid $150 for a diagnosis. They didn't find anything and probably didn't check the vehicle that well; they needed more time, but I don't have an unlimited budget to pay for the diagnosis. I want to try and figure it out by myself since it is a little expensive. I tried that shop, and honestly, I just wasted that money.

Any advice on what I should check? I'm close to just giving up on the car, not tuning it, just leaving it stock and hoping that the knock activity won't cause any damage to the engine in the long run. I appreciate any advice I can get Thanks!

Most recent Data
Rectangle Font Parallel Pattern Number
 

·
Tech Advisor
Joined
·
56 Posts
This is all you would really need to get.............

DEPSTECH Wireless Endoscope, IP67 Waterproof WiFi Borescope Inspection 2.0 Megapixels HD Snake Camera for Android and iOS Smartphone, iPhone, iPad, Samsung -Black(11.5FT): Amazon.com: Industrial & Scientific

For $150 diag fee, they should have looked in the cylinders and provided a pics......

IMHO, any knock at all is a concern. I am still swagging either carbon buildup or poor gas...... Costco fuel is ok, but they are missing the additives the top tier fuels do have. I'm not a fan of the K&N intakes as they are known to have issues with the sensors.... try putting the oem intake back on if you have it, and clean the TPS & MAF.

The only other thought I have is to add 1/2 oz acetone per gallon to the fuel, if that clears it up/helps, then you know it is either carbon buildup or gas quality issue.
 

·
Registered
Mustang GT 2017
Joined
·
3 Posts
Discussion Starter · #9 ·
Update:

I ran the car almost out of fuel and filled a little bit from another gas station with 91 again. The car has been running with that Octane for over a month now. I did not fill up the car because I bought only one bottle of the octane Booster, so I bought like $30 of gas, and I added the Octane booster ran the car for another 30 miles to get that new mix into the system and then started data logging again. I did some regular maintenance before data logging , oil change and replaced the PCV valve because the old one was loose. Since the car was on a jack stand, I checked for clearance and tried to move everything I could to see if I could catch something loose, but I saw nothing. Did the 4 following runs:

Run 1 Stock tune (8 minutes):
The highest nock value detected was +15, which is too high and unusual. It did not happen at WOT.
Rectangle Font Parallel Pattern Number


Run 2 Stock tune (15 minutes):
The highest nock value detected was 2.25 same thing did not happen at WOT.
Azure Rectangle Font Parallel Pattern


Run 3 Ortiz tune #1 (7 minutes)
The highest nock value detected was 7.42 at WOT.
Product Rectangle Azure Purple Font


Run 4 Ortiz tune #1 (5 minutes)
The highest nock value detected was 8.23 at WOT.
Rectangle Font Parallel Pattern Number



Here's the link with all 4 data logs for whoever wants to look at them with more details Livelink:

Mustang GT 2017 Data Logs 10/14/2022 - Google Drive


What Should I do next? Is there a way by just looking at the data to Identify if it is accurate or fake knock?
 

·
Registered
Joined
·
1 Posts
Update:

I ran the car almost out of fuel and filled a little bit from another gas station with 91 again. The car has been running with that Octane for over a month now. I did not fill up the car because I bought only one bottle of the octane Booster, so I bought like $30 of gas, and I added the Octane booster ran the car for another 30 miles to get that new mix into the system and then started data logging again. I did some regular maintenance before data logging , oil change and replaced the PCV valve because the old one was loose. Since the car was on a jack stand, I checked for clearance and tried to move everything I could to see if I could catch something loose, but I saw nothing. Did the 4 following runs:

Run 1 Stock tune (8 minutes):
The highest nock value detected was +15, which is too high and unusual. It did not happen at WOT.
View attachment 305274

Run 2 Stock tune (15 minutes):
The highest nock value detected was 2.25 same thing did not happen at WOT.
View attachment 305275

Run 3 Ortiz tune #1 (7 minutes)
The highest nock value detected was 7.42 at WOT.
View attachment 305276

Run 4 Ortiz tune #1 (5 minutes)
The highest nock value detected was 8.23 at WOT.
View attachment 305277


Here's the link with all 4 data logs for whoever wants to look at them with more details Livelink:

Mustang GT 2017 Data Logs 10/14/2022 - Google Drive


What Should I do next? Is there a way by just looking at the data to Identify if it is accurate or fake knock?
Wow! Thank you!
 
1 - 11 of 11 Posts
Top