2015 ZL1 knock? Conclusion @ 4/27/15

[angryBits]

Problem only occurs under load while in boost. So they'd need to drive it.

I think I ruled out burnouts since I've been checking back and I see the gas tank has gotten even lower. So they're doing stuff -- but why has the odometer not changed. Hmm....

Hopefully I get a call today.

Edit: 2.2 gallons have been consumed, but the odo hasn't changed. *head scratch* Idling for the last hour? Ouch...

[Vroom]

When I took my car in to Dublin for the tick noise I had, the guy said, and I quote, "I drove it pretty hard all weekend" and everything was fine. He's put almost 100 miles on it...And that's why they'll never touch my car again. Not sure sitting around idling is much better.

[angryBits]

Originally Posted by Vroom

When I took my car in to Dublin for the tick noise I had, the guy said, and I quote, "I drove it pretty hard all weekend" and everything was fine. He's put almost 100 miles on it...And that's why they'll never touch my car again. Not sure sitting around idling is much better.

WOW... Just WOW!

That's totally unacceptable. The dude basically borrowed your car for a weekend without your permission. WOW

The dealership is only as good as the honesty of the individuals. I think its all about getting the right person to help you out.

[angryBits]

UPDATE:

Dealership called me and said they checked the sensors and everything checked out.

What they said was the problem:
The GM Tech arrived and verified the issue. They're calling it a "ping". He did a "fuel consumption test" and he said he found 10% Ethanol in the gas and determined that to be the problem...

Their suggestion:
Take the car home, use up the gas and put good gas in the car and come back if it happens again.

My thoughts on their suggestion:
Are you kidding? Most gas here in California is advertised as having 10% ethanol in it. How was this a surprise? WTF is good gas? I have to find some random gas station that sells gas without ethanol? Really? Why did you sell this car in California? If gas REALLY is the issue, then they need to fix the car to run without pinging on 91 w/ 10% ethanol. Period.

What I said:
The car has been pinging since day one with whatever gas they put in it. I've driven other ZL1s and they didn't ping -- one of which was on their dealership lot. Rather than wasting my time and theirs, drain the 91 in the tank -- you can keep it. Put what you believe to be good 91 in the tank, charge me for the gas, and test it out and we'll go from there. If there is a ping, then it wasn't the gas. If there is a ping, then it was the gas and I will insist they tune my car to run on 91 w/ E10 -- i don't care if I lose 5hp. They need to tune the car because I can't or I will void my warranty.

The service guy said he'd talk to the tech. Hopefully they recognize this as the way to go.

Dang this is frustrating. I was hoping they wouldn't BS me. Clearly the GM Tech doesn't care about wasting my time.

*sigh* So far this isn't going BAD, just a little less than ideal. We'll see what comes next.

[KaBoom1701]

Originally Posted by angryBits

UPDATE:

Dealership called me and said they checked the sensors and everything checked out.

What they said was the problem:
The GM Tech arrived and verified the issue. They're calling it a "ping". He did a "fuel consumption test" and he said he found 10% Ethanol in the gas and determined that to be the problem...

Their suggestion:
Take the car home, use up the gas and put good gas in the car and come back if it happens again.

My thoughts on their suggestion:
Are you kidding? Most gas here in California is advertised as having 10% ethanol in it. How was this a surprise? WTF is good gas? I have to find some random gas station that sells gas without ethanol? Really? Why did you sell this car in California? If gas REALLY is the issue, then they need to fix the car to run without pinging on 91 w/ 10% ethanol. Period.

What I said:
The car has been pinging since day one with whatever gas they put in it. I've driven other ZL1s and they didn't ping -- one of which was on their dealership lot. Rather than wasting my time and theirs, drain the 91 in the tank -- you can keep it. Put what you believe to be good 91 in the tank, charge me for the gas, and test it out and we'll go from there. If there is a ping, then it wasn't the gas. If there is a ping, then it was the gas and I will insist they tune my car to run on 91 w/ E10 -- i don't care if I lose 5hp. They need to tune the car because I can't or I will void my warranty.

The service guy said he'd talk to the tech. Hopefully they recognize this as the way to go.

Dang this is frustrating. I was hoping they wouldn't BS me. Clearly the GM Tech doesn't care about wasting my time.

*sigh* So far this isn't going BAD, just a little less than ideal. We'll see what comes next.

Wow,,that bites.

Sorry to hear they just tossed you aside.

But with that said I do think there is a simple fix....Torco.

Remember that GM has these high performance ZL1 cars tuned to 93 octane from the factory. You and I live in Cali where the highest octane we can buy at the pump is 91. In order to effectively take advantage of all the ZL1 HP has to offer we need to bump on octane up to 93+. The only way to do that is to add a respected fuel additive such as Torco.

I know some people call out the MMT that is used in Torco but I found this small bit of info doing some Google searches.

"Quote:
Good for you doing your research. One of the main components in Torco UL Accelerator is MMT or Manganese. This is what leaves an orange or tan residue on your plugs. Basically this is a lead substitute as you know lead makes octane numbers go up, so does Manganese. It will not harm your fuel system or any part of your emission system or spark plugs for that matter. The residue is simply un-burnt manganese. MMT has been used as a lead substitute for raising octane in many country's other than the USA for years. For instance in Australia you can get a 102 octane fuel at the pump (MMT). MMT got a bad name back in the 70's when the USA went to unleaded fuels, it was strictly marketing "mud slinging" that started in the aviation industry (which aviation fuel still uses lead). Do some research on MMT. Torco Accelerator also has other chemicals which help the burn characteristics. Remember Octane dose not equal horse power, it just help the engine resist detonation. Good luck and thanks for the question. -Don

Don Clark
National Sales Director "

Ya I know Torco isn't cheap but it solves the issue. The car I purchased has been running Torco form day one. I plan on continuing to use Torco on every gas fill up. Car runs great and no KR or pinging issue at all.

[angryBits]

Originally Posted by KaBoom1701

Wow,,that bites.

Sorry to hear they just tossed you aside.

But with that said I do think there is a simple fix....Torco.

Remember that GM has these high performance ZL1 cars tuned to 93 octane from the factory. You and I live in Cali where the highest octane we can buy at the pump is 91. In order to effectively take advantage of all the ZL1 HP has to offer we need to bump on octane up to 93+. The only way to do that is to add a respected fuel additive such as Torco.

I know some people call out the MMT that is used in Torco but I found this small bit of info doing some Google searches.

"Quote:
Good for you doing your research. One of the main components in Torco UL Accelerator is MMT or Manganese. This is what leaves an orange or tan residue on your plugs. Basically this is a lead substitute as you know lead makes octane numbers go up, so does Manganese. It will not harm your fuel system or any part of your emission system or spark plugs for that matter. The residue is simply un-burnt manganese. MMT has been used as a lead substitute for raising octane in many country's other than the USA for years. For instance in Australia you can get a 102 octane fuel at the pump (MMT). MMT got a bad name back in the 70's when the USA went to unleaded fuels, it was strictly marketing "mud slinging" that started in the aviation industry (which aviation fuel still uses lead). Do some research on MMT. Torco Accelerator also has other chemicals which help the burn characteristics. Remember Octane dose not equal horse power, it just help the engine resist detonation. Good luck and thanks for the question. -Don

Don Clark
National Sales Director "

Ya I know Torco isn't cheap but it solves the issue. The car I purchased has been running Torco form day one. I plan on continuing to use Torco on every gas fill up. Car runs great and no KR or pinging issue at all.

I get you on Torco -- but the fact of the matter is, the car should be able to run on pump gas here in California. Even if that means the car needs to tune itself down and lose 5-10hp.

It's not over yet -- I've been spying on them with my Onstar app. They took my advice because I see the car now has a full tank of gas. So either the issue persists or it doesnt.

If it does (proving the gas is the issue) then I will demand they re-tune my car to run on 91 w/ E10 as I am unable to do so without voiding the warranty. If they agree to this, then I'll be happy with the result.

If they don't re-tune... Then I have to come up with creative ways to do it myself without touching the software.

[angryBits]

Originally Posted by angryBits

If they don't re-tune... Then I have to come up with creative ways to do it myself without touching the software.

Thinking about this more as it's a good possibility :(

1. Adding a Oil Separator will reduce oil from getting into the combustion which should help a bit with knock.

2. Trick the computer into running richer as a lean Air Flow Ratio causes knock. How to do this without touching the computer? I'm thinking maybe adding a small valve to the intake AFTER the MAF Sensor. The valve should allow me to fine-tune-reduce ACTUAL air pressure AFTER the sensor has recorded it, which means the computer will think it needs to add fuel for more air than there actually is, causing a richer Air Fuel Ratio. Should totally work, however the result will be a slight reduction in power, maybe 5whp which I could gain back with some non-tune bolt ons.

3. Run with Torco - which I really don't want to NEED to do.

None of these should void my warranty. Well #2 might, but how would they know.

[ac223mal]

I am watching this thread, to see what the outcome is. I am not having problems yet, but I only have access to 91 octane gas in my area as well. According to the owners manual you only need 91 octane or higher, so I dont understand why the car would be tuned for 93 octane from the factory. Like Six.TwoSC mentioned, I wouldnt have purchased the car if it need 93 octane, or had to rely on Torco to get the car to run correctly.

We also have the 10% ethanol blend here (I believe most high pollution area have a 90/10 blend in the summer). If that is really the problem, then most Z's would be suffering from this problem.

Very interested...

[Chrispy]

Pump gas in Cali sucks period. Cobb and other tuners usually have a Cali 91 map and a rest of USA map lol.

It's your state not the car that has a problem

Look for a Shell station. In Canada you get 91 octane at Shell with no ethanol added. Not sure if it's the case in Cali but worth checking out. (California might mandate 10% for all blends, not sure)

Oh and your only option really from your list above is option 3 if you aren't going to tune and take some timing out or find somewhere local that sells unleaded race gas.

[angryBits]

Originally Posted by ac223mal

I am watching this thread, to see what the outcome is. I am not having problems yet, but I only have access to 91 octane gas in my area as well. According to the owners manual you only need 91 octane or higher, so I dont understand why the car would be tuned for 93 octane from the factory. Like Six.TwoSC mentioned, I wouldnt have purchased the car if it need 93 octane, or had to rely on Torco to get the car to run correctly.

We also have the 10% ethanol blend here (I believe most high pollution area have a 90/10 blend in the summer). If that is really the problem, then most Z's would be suffering from this problem.

Very interested...

Agreed

[angryBits]

Originally Posted by Chrispy

Pump gas in Cali sucks period. Cobb and other tuners usually have a Cali 91 map and a rest of USA map lol.

It's your state not the car that has a problem

Look for a Shell station. In Canada you get 91 octane at Shell with no ethanol added. Not sure if it's the case in Cali but worth checking out. (California might mandate 10% for all blends, not sure)

Oh and your only option really from your list above is option 3 if you aren't going to tune and take some timing out or find somewhere local that sells unleaded race gas.

It's the manufacturers lack of support for California Gas that is the problem, not California Gas. If 91 is required without the 10% ethanol, then it should have been documented in the manual, in which case I would not have bought the car.

[angryBits]

Originally Posted by ac223mal

I am watching this thread, to see what the outcome is. I am not having problems yet, but I only have access to 91 octane gas in my area as well. According to the owners manual you only need 91 octane or higher, so I dont understand why the car would be tuned for 93 octane from the factory. Like Six.TwoSC mentioned, I wouldnt have purchased the car if it need 93 octane, or had to rely on Torco to get the car to run correctly.

We also have the 10% ethanol blend here (I believe most high pollution area have a 90/10 blend in the summer). If that is really the problem, then most Z's would be suffering from this problem.

Very interested...

That PDF you posted was very useful.

When I look up ASTM standard D4814 mentioned in that PDF as the required guideline for gas to be used in our cars, seen HERE in Section 1.8 (D), it clearly says 1-10% ethanol is okay. However the GM Tech is saying its not.

EDIT: btw - this proves that California's crap gas needs to be supported by the ZL1 because the manual says so.



You sir have armed me with a legal contract! Thank you!

[Chrispy]

Well it is supported. The car won't blow up or lose a ringland due to California 91 gas, you'll just have KR and eventually move to the low octane table.

It works exactly as designed for Cali gas or from other bad gas you get at the pump. (When a pump truck puts 87 into the 91-93 tanks for example)

If you want the full performance out of the car use Torco or a race gas blend, otherwise you'll need to suck it up and live with some KR, a shift to the low octane table and less horsepower/torque.

[ac223mal]

Originally Posted by Chrispy

Well it is supported. The car won't blow up or lose a ringland due to California 91 gas, you'll just have KR and eventually move to the low octane table.

It works exactly as designed for Cali gas or from other bad gas you get at the pump. (When a pump truck puts 87 into the 91-93 tanks for example)

If you want the full performance out of the car use Torco or a race gas blend, otherwise you'll need to suck it up and live with some KR, a shift to the low octane table and less horsepower/torque.

Not to start an argument, but I respectfully disagree...If I put 87 octane gasoline in the car, then I would expect to car to move to the lower octane table and have performance suffer. However, If I am using fuel that meets what it is in the owners manual (assuming that you didn't get a bad batch of gas) then I shouldn't have to suck it up and I should have advertised performance. If I use higher octane gas or Torco then I should expect better than advertised performance.

Since the 91 octane 90/10 blend meets the requirement established by GM why should more be done to get the advertised performance? I should have the performance advertised without jumping through hoops as long as I am using the specified fuel.

The brakes for example come with DOT3 brake fluid, owners manual lets me know if I want to race I need to flush and provide DOT4 brake fluid. So I know if I race and don't upgrade the brakes fluid I will have problems. The owners manual doesn't tell me if I want 580/556 that I need 93 octane fuel. So I expect to have 580/556 unless I put in gas lower than 91 octane.