So here recently I changed the plugs in my cobalt and went with a step colder (NGK 3787). While I was driving at home I experienced no knock retard at all for two weeks after. Well I'm on vacation now (myrtle beach) and we rode my Balt and now everytime I touch boost I'm getting knock retard. After I noticed it I went straight and dumped 2 bottles of 104 in it to try to help but still getting the knock retard. Tomorrow I'm going to an auto parts to get stock heat range plugs and changing them in the parking lot of our hotel. I don't know how long its been doing it and we've been here about 2 days (it was a 8 hour drive). Have I done any damage riding it around like this? I've been keeping it out of boost since I realized it. The highest I noticed the knock was 6 but as soon as it touches boost its 1-3.

 

I'm not sure why people insist on trying to fix something not broken. Stock range plugs.

 

^^ X2. im on stock plugs at stock gap with a BNR and have no issues. id put some stockers back in.

 

To answer your question, you're fine. I'll agree with those two, you should stay with stock plugs.

Also, any of those bottles of octane booster are basically full of snake oil. Waste of money and time and can actually make your car lose horsepower.

 

this is a good thread to know....but one thing for sure I didn't know bout that on the octane boosters....how is it that they reduce power, sorry for the question, but just curious for future reference?

 

One point of octane increase is what it is advertised to do. Know what that means? .1 octane increase. Do the math on how much you need to increase it a significant amount.

 

Only conditions where I would get the occasional knocks are - 85+F temp and intake temp of 89+F, AC on. 2-3 degrees and I have engine and trans mounts which could factor in the false knocks in those conditions.
As for those actane boost, they are junk like many here already said. I tried a bottle last year and the only thing it does is coats my sparkplugs with a rusty color. The only that works is mix your pump gas with some 110+ octane unleaded race fuel.

 

Well I changed my plugs with some autolite iridiums, stock replacement and I'm still getting the knock retard. Instead of pulling 1-3 as soon as boost starts Its staying at zero unless I somewhat get on it and only at WOT it'll go to 3. Whats the problem? The plugs that came out were rust colored now that you say that. Should I just ignore it and it'll go away when I get home? I didn't notice it until we filled up at a Wal Mart, maybe bad gas?

 

Maybe your car was perfectly tuned for the elevation air density and fuel where you live....but not where u r now. Just dont get on it till u get back.

 

Was thinking the same thing.

 

Its the stock tune. I have trifecta but the problem is happening on the stock one. My only mods are the tune, catless downpipe, and a kand n SRI. But after driving it around a little while with the new plugs the knock has went completely away. I guess the car just need to relearn itself for the new plugs.

 

Someone needs to make a sticky, stock plugs, stock brand. they work the best, no issues with them, i also tried one step colder, nothing but issues. went back to stock, issues solved

 

Don't forget that a bad 02 sensor ( the one at the turbo ) would cause crazy ass knock too at lease from my own experience.

 

It would set a code, no? Or is it possible for the reading to just be off a little without a code?

On a side note.... I've been playing around with the filter position on the K&N intake to check out my AFR's. In doing so I'm finding that my KR also changes but I'll have to watch it long term. Tonight it was showing zero knock but we'll see long term.

On topic with spark plugs.... I've had some oddball results.
Engine was rebuilt and builder just put in some cheapies to get it running. I said no problem. I'll run 'em for a while and throw stockers in later. Later on when I started getting aggressive I saw some KR. I put in stockers thinking that it could possibly clear it up. The KR got MUCH worse with the OEM plugs!

So then I went one step colder with the 3787's. KR was still there but did get better.
Like I said though. I've been messing around with filter position. Right now KR is gone. It may just be coincidence. I'll have to watch it for a longer period.

 

Before I knew about the 02 sensor issue, my tuner at th time did multiple tunes to get it to zero knock. Then a day or two, I get the same knock. It seems like when the sensor gone past/got really hot a certain temp that it acts crazy? And make sure you have no loose suspension parts or things that rattles against the block which could also cause false knock.