I am concerned with the amount of spark knock my 09 G has and am wondering if there is anything I can do or ask my service department to check. I always use 91 when filling up and prefer chevron gas as my primary retailer. The car has just under 6500 miles and is 6 months old. The reason I think this is a problem is that one of my family members has a 10 g vert manual tranny and it too has alot of audible knock as well. Any suggestions are greatly appreciated.

 

Hrmm you definitely shouldn't be hearing any knock especially with a car that new. Have you ever had a scan tool hooked up to check out what the knock sensor is actually seeing, that would basically confirm whether or not the knock is indeed detonation. Knock sensors retard timing, so one might be able to see if timing is getting pulled back.

 

Are you sure the sound you're hearing is knock?

 

First thing I would do is try fueling at a different location. You may not be getting 91 octane. If fuel purchased at other location silences the knock then you have found the problem. If this does not cure it take it to the dealer.

Bob

 

Thanks for the input. I am absolutly positive the noise I am hearing is spark knock. I know this because under load just before the car bogs in a gear to high for its speed, there is knocking sound that is similar to the sound Clark Griswolds family truckster made when he first bought it in the movie National Lampoons Vacation.....(stoopid example i know but I could not resist.). The other reason I know this is spark knock is because my family members Vert G37 does the same thing and the owner of that car is much more then a car guy then even me (which is to say alot). I have tried other gas retailers including Mobil and 76 and have always used the crappy 91 octane in the state of California. I do not want to try 100 octane since our cars will not be able to burn the fuel based on ECU parameters and the unspend fuel will just clog my Cat and cause premature damage to it.

I guess what I really want to know is if anyone has taken their car in to a dealer and had any results with the techs making adjustments? If not, I may just be screwed.

BTW - this knocking sound is way more annoying to me then the high pitch frequency our cars are already plagued with.......

 

I don't get knocking or the whine in mine. I'd vote take it in.

 

The only times I hear spark knock is when I roll off the line in 2nd gear and don’t give it enough gas. The car will bog and produce spark knock. This is 100% caused by my driving. This occasionally occurs when I don’t feel like starting off in 1st gear.