Topic: Spark Plugs....Please Advise

[redlinedude]

I have a 2007 Sky Redline with 11,700 miles. I have the BSR tune and K&N Air Filter. I have always put 94 octane in it until they stopped selling it in Ohio. (BTW I have cleaned my MAF sensor with the MAF spray cleaner per the instructions on the can). Over time I have experienced detonation when I tune my car with the BSR tune and the car is under load in third or fourth gear. I guess I had a TSB done by my Saturn dealer for a spark plug change from the 41-102's to the 41-108 "hotter plug". The current 41-108 plugs are gapped at 0.32 (checked 04/10/12 at 0.35..thanks Saturn)from the factory (verified). Should I try a "colder" plug or downsize the current plug gap to 0.28-0.30? Let me know what you think....I am all ears.

[Gentleman Jack]

I have a 2007 Sky Redline with 11,700 miles. I have the BSR tune and K&N Air Filter. I have always put 94 octane in it until they stopped selling it in Ohio. (BTW I have cleaned my MAF sensor with the MAF spray cleaner per the instructions on the can). Over time I have experienced detonation when I tune my car with the BSR tune and the car is under load in third or fourth gear. I guess I had a TSB done by my Saturn dealer for a spark plug change from the 41-102's to the 41-108 "hotter plug". The current 41-108 plugs are gapped at 0.32 from the factory (verified). Should I try a "colder" plug or downsize the current plug gap to 0.28-0.30? Let me know what you think....I am all ears.

I think going back to the original plug and gaping to 0.30 was the recommendation, but wait for someone to confirm.

[tazz]

Did they drop to 92 octane?
He could try the colder plug but he probably really NEEDS to get the tune re-calibrated for the lower octane.
Splash in 2-3 gals of E85 each tankful and that will bring the octane up 1-2 points.

[Wartie]

Did they drop to 92 octane?
He could try the colder plug but he probably really NEEDS to get the tune re-calibrated for the lower octane.
Splash in 2-3 gals of E85 each tankful and that will bring the octane up 1-2 points.

Tazz,
Redlinedude and I are in the same area, I have no problems finding 93 here. But the E85 is a good idea.

[miller11386]

Yeah I am in NE ohio (Driving all over it actually) and 93 octane is pretty abundant here. I have no issues in the Canton, Akron, Cleveland, Streetsboro, Boardman, areas finding 93... actually I can't think of a station without 93 octane.

Throughout the Eastern US always look for BP stations for reliable 93 octane. I have never found a BP station in OH, WV, VA, NC, or SC that didn't have 93 at the pump.

I agree , dont run the BSR tune unless you put in 93 octane. Its not a good idea.

Now E85? that is tough to find. Only a pump in Barberton & one in Columbiana county as far as I know.

[1LILNDN]

       I have always put 94 octane in it until they stopped selling it in Ohio.

He started out talking about ( 94 )  not ( 93 ) Octane 

As Tazz said put a few gal. of E85 in and see what happens if you can find it.

[snaponbob]

The 102 plugs are no longer available so you'll need to find equivalents. If BSR is still around, have them reset the tune 1 point below what is available (safety factor). Keep in mind that in some areas (if you travel) all you can get is 91 octane. All that said, one point of octane shouldn't be THAT bad on the performance in higher gears, should it?

[Wartie]

Yeah I am in NE ohio (Driving all over it actually) and 93 octane is pretty abundant here. I have no issues in the Canton, Akron, Cleveland, Streetsboro, Boardman, areas finding 93... actually I can't think of a station without 93 octane.

Throughout the Eastern US always look for BP stations for reliable 93 octane. I have never found a BP station in OH, WV, VA, NC, or SC that didn't have 93 at the pump.

I agree , dont run the BSR tune unless you put in 93 octane. Its not a good idea.

Now E85? that is tough to find. Only a pump in Barberton & one in Columbiana county as far as I know.

E85 in Ohio, I am not sure how current this is. http://e85vehicles.com/e85-stations/e85-stations-in-ohio.html

[miller11386]

I know one of the stations listed on the site you linked out by norwalk does not have E85 anymore (saw it on another forum)

Unfortunately if I ran ethanol, by the time I drove to get it and drove home, I would be close to out

[snaponbob]

@ redlinedude - have you contacted BSR about this. I would bet real money the problem is greater than colder plugs will fix. One point of octane should not be inducing audible knock. If it does, the car was already knocking and the ECM was controlling it.

[Kelu]

1) Try NGK 6509 or 3787 being heat range 6 instead of heat range 5 as OEM ones. Gapped around 0.028-0.030
2) How you noticed detonations?
3) Talk with BSR about this or change your tune

[redlinedude]

1) Try NGK 6509 or 3787 being heat range 6 instead of heat range 5 as OEM ones. Gapped around 0.028-0.030
2) How you noticed detonations?
3) Talk with BSR about this or change your tune

Thank you for the plug options Kelu. Only when I "tune" my car do I experience detonation. There are no CEL'... When I am running stock I get around 14-16lbs boost but when I tune the car it goes up to 23lbs boost. When I am in fourth gear and step on it I can hear the knocking sound (it almost sounds like a diesel engine for a second or two). I have tried a couple of different Octane boosts and wonder if it they could have fouled O2 sensors or messed with the CAT ?? How could I check these ??? I only run 93 octane in my car since Sunoco stopped carrying 94 here in Ohio. I talked to BSR. They want $80.00 for me to send them my info for them to analyze. I may just get rid of the BSR tune and go with the Trifecta tune and have Vince analyze my data and tune my car accordingly. 

[tazz]

I'm not quite following you.
When YOU tune your car??
Do you mean when you upload the BSR tune or are you Altering the BSR tune?
In addition BSR is going to charge you $80 to adjust there tune but what is Vince going to charge to write a tune for you  PLUS you will need to RENT Data Cable to upload his tune and that is a $200 deposit that you get back once you send it back in and the charge of the Trifecta tune or is this not the case anymore?
Just trying to figure out what you want to do and what's happening.
Oh BTW MOST octane booster DON"T DO SQUAT.

[J_Bond]

ECM needs to be RE-TUNED!  if you are regularly using 94 octane and your tune is set to push as much power it can based on the octane rating, there's going to be problems utilizing a substantially lower octane rated gas with AFR's set for 94. 
 Your plugs are likely toast and need to be replaced, but don't bother replacing them until you are sitting on the Dyno re-tuning, and get all of your AFR's set according to the 92 or 91 octane you are running.  I had the same thing happen to me with my SLK32 supercharged.  I had a 93 octane tune and suddenly every station in the area dropped to 91-octane.  it was enough to confuse the ECM and have me running too rich and had an awful idle. 

And Tazz is right, octane booster won't do jack.

[redlinedude]

I'm not quite following you.
When YOU tune your car??
Do you mean when you upload the BSR tune or are you Altering the BSR tune?
In addition BSR is going to charge you $80 to adjust there tune but what is Vince going to charge to write a tune for you  PLUS you will need to RENT Data Cable to upload his tune and that is a $200 deposit that you get back once you send it back in and the charge of the Trifecta tune or is this not the case anymore?
Just trying to figure out what you want to do and what's happening.
Oh BTW MOST octane booster DON"T DO SQUAT.

BSR was one of the first "tunes" available for the 2.0 LNF.  You can install the "tune" or return it back to the stock  settings with no adjustment settings. I was told if I pay them $80.00 and send them the data from my tuner they will "look at the data but no guarantees". I may just scrap the BSR tuner and go will a tune that I can adjust as I modify my car down the road (high-flow cat, 3" exhaust, upgraded intercooler, etc..).

[snaponbob]

BSR was one of the first "tunes" available for the 2.0 LNF.  You can install the "tune" or return it back to the stock  settings with no adjustment settings. I was told if I pay them $80.00 and send them the data from my tuner they will "look at the data but no guarantees". I may just scrap the BSR tuner and go will a tune that I can adjust as I modify my car down the road (high-flow cat, 3" exhaust, upgraded intercooler, etc..).

Trifecta and Westers both do a great job initially. If you know somebody with HP Tuners, or buy it yourself, you can get a tune from Westers and have future tweaks done at little to nothing additional. If I went back to gasoline (vs gas and E85 blend) I would use Westers again. Great guy, fast response to e-mails and re-tweaks.

[RufusMacblorf]

I had a very similar problem.  I had my original ECU and a separate ECU with the GMR tune.  With the original ECU I never experienced detonation.  With the tuned ECU, I had the same audible detonation under heavy boost (not necessarily full boost) at speed in third or fourth gear.  I wouldn't get the detonation when I was driving hard through the twisties, even at WOT, but if I then drove an hour at regular freeway speeds back to the city, it would detonate.  I came to two possible conclusions:

1) The tune was set to a default that was too lean or too rich.  When I did a lot of sequential WOT driving, it would "learn" to adjust, but would forget after a period without WOT.

2) Under high boost, oil was getting past the check-valve into the charge-pipe, which was then messing up the AF mixture and causing detonation.

I replaced the GMR tune with the Trifecta tune last fall.  I experienced the detonation once with the new tune.  Over the winter I installed an oil catch can and a high-flow cat, and I replaced the check-valve from the charge pipe going into the intake manifold.  I haven't been able to reproduce the problem, though I only recently de-winterized and started driving the car again.  If I were in your shoes, I'd install an oil catch can and a new check valve.  If that doesn't work, try the more expensive option of a new tune.

[redlinedude]

I pulled the spark plugs today (cold engine) and they were all at 0.35 and they all looked good. I carefully adjusted them down to 0.30. Before I tuned the car, I drove it around and it seemed a little slower than it did earlier this morning. Then I installed the BSR Tune and drove the car around town and on the freeway. The car is much faster now (as it should be) with no noticeable detonation !! I even drove the car to max boost of 23 psi for a while and when I slowed down the car did not go into limp mode (as it did in the past before the detonation issue). Thanks to everyone for your knowledge and input. I hate to ask this but should I go back up a little to 0.32 or leave it where it is??

[snaponbob]

I pulled the spark plugs today (cold engine) and they were all at 0.35 and they all looked good. I carefully adjusted them down to 0.30. Before I tuned the car, I drove it around and it seemed a little slower than it did earlier this morning. Then I installed the BSR Tune and drove the car around town and on the freeway. The car is much faster now (as it should be) with no noticeable detonation !! I even drove the car to max boost of 23 psi for a while and when I slowed down the car did not go into limp mode (as it did in the past before the detonation issue). Thanks to everyone for your knowledge and input. I hate to ask this but should I go back up a little to 0.32 or leave it where it is??

NO !!  If it works, don't fix it.  This is what may have been happening - the wider gap caused a spark that the increased boost and power can squash. Misfire causes unburned fuel which means more unburned oxygen that the O2 sensors sees as "lean". If the fuel system is being controlled by the tune and spark is advanced - knock. Seems counter intuitive, but it can happen. (Just some conjecture.) Bottom line, if it is running well, don't mess with it anymore.

[redlinedude]

So lowering the stock spark plug gap from 0.35 to 0.30 worked for me and no more (audible) detonation!!  Why did this adjustment work for me??

[snaponbob]

The engine is designed and built to develop 260 BHP and 260 ft/lbs torque on 91 octane gas while meeting emission laws in 50 states and Canada. Under nominal conditions the spark plug gap of .035 works. Start tuning and conditions change. Power generation increases and by necessity that means higher air flow, more gasoline supplied, and more combustion chamber heat and activity. Early on, GM provided a TSB that instructed changing the original plugs to plugs that are a couple heat ranges lower to correct some driveability issues. First hint they missed on the stock set up. As mods and tunes are done, the environment for the spark plug becomes more difficult. Closing the gap is a common change on forced induction engines because the spark becomes erratic and even can be blown out (like a match) under load causing all sorts of problems. That is what happened to you. Glad the cheap fix worked.

[ChopTop]

Catalytic converter test (skip to 1:00)

How to check your vehicle's catalytic converter.

spark plug test
Check your own car's ignition system in seconds.

[redlinedude]

Thanks to snaponbob for the knowledge and choptop for the videos!! I hope this thread helps anyone else that has a similar problem to mine. 

[tazz]

Bob
You must mean GM moved to a HOTTER plug.
The original plugs GM used were a Colder plug that caused starting and idling issues so Gm moved to the AC 108's a hotter plug because of carbon fouling issues.
If your saying that he has the hotter plug since they changed them to the AC 108's then you are correct.  Ac 103's COLDER plug Ac 108's HOTTER plug.

[redlinedude]

Bob
You must mean GM moved to a HOTTER plug.
The original plugs GM used were a Colder plug that caused starting and idling issues so Gm moved to the AC 108's a hotter plug because of carbon fouling issues.
If your saying that he has the hotter plug since they changed them to the AC 108's then you are correct.  Ac 103's COLDER plug Ac 108's HOTTER plug.

Tazz, Do you know of anyone that has a 2.0 LNF with a "tune" that uses the 41-103's?? If so what gap setting? Do you think these plugs would work better for me??