I took the car out the other day to drive to work. It was abnormally warm for the seattle area and I ended up getting caught in traffic. After sitting in traffic for a while I turned the fans on just to make sure the car stayed cool.

BUT once I got out of traffic I noticed that if I poked the throttle while it was under 2500 RPM it would knock (audibly) for a second and then go away once the car got above 2500.

Just recently I changed plugs over to a Bosh Platinum +4. Could these plugs just be to "hot" and be causing almost a "Dieseling" effect?

Any input would be appreciated.

 

Try NGK TR6 plugs, you can gap them up for your application, would stay under .060" as factory they are .035".

 

I dont mean to be rude about your choice in plugs, but we used ot have *terrible* luck with those +4's in LT1s. We went right back to what we were using. Try TR6 or TR55s.

Wha tdo you have for a MAF? I had to switch back to a stock MAF on my C5 (lots of mods) because of <2500 detonation in the summer.

Chris

 

the MAF is stock other than descreened. Never had a problem in the past with it. I am guessing it is just the plugs. It is the first time I have used them in an LS1. I actually had good luck with the +4's in my LT1 car so I figured I would try them in the LS1.

 

You gettin any oil in the intake? I have a really audible ping under low RPM heavy load applications. Its cause the oil is diluting the fuel and lowering the hell outta my octane.

Plus, this 91 crap in Oklahoma isnt helpin.




Stu

 

Well I am getting oil but I dont think it is any worse than anyone else's oil consuption problem.

This didnt start happening until AFTER I changed the plugs. I talked to another guy that had the same problem with the Bosch plugs. He said it ran fine until it got hot outside.

 

NataSS, I just started having that EXACT same problem yesterday!! I have TR-6's as well. My compression is right around 10.8:1, I think I may have gotten some crappy gas + the heat is causing it I think. My ping comes on right around 2000 rpm, and I have the ls6 pcv with a catch can. Perhaps you got some crappy gas too?? Its worth checking out.

Matt

 

Definitely swap the plugs out to some TR6s gapped at .045". Hopefully this will help solve your problem.

Jason

 

i get the same crap off and on, but i just switch my edit programs to one with less timing. Im running 11:1CR on 5.3 tea heads also. But under part throttle when the verter is locked ill get some ping. Now when the verter unlocks its fine, but its just any load under slight throttle in OD causes it. I believe its just the weather and bad gas combo. Im gonna try my other file with the added timing this fall and i bet its fine. but it sounds like I have a loose headers banging around when it makes that sound... always something

 

thanks alot for the input guys. I'll get those plugs swapped asap

 

I've had the same problems in the heat... Just to confirm your not the only one