2006 trailblazer ss

fredg369 · December 30, 2005

Don't know if anyone has worked on the 6.0ltr in the TB SS yet.

But maybe general GM tech could help.

I picked up the TB SS and the dealer put s**tty gas in a high-performance engine.

Go figure!

When the engine was at idle...like at a red light....I would feel what I call knock some shaking from the engine.

I drove it untill there was a 1/4 tank and fulled up with 93oct.Still feel knock.

Let that tank go down to less then a 1/4 tank and did a complete full-up with 94 again....It smoothed it out for the most part but still feel it now and then.

Should I wait to get it checked...mybe the computers still adjusting...or should I bring it back ASAP....The TB has around 200 miles on it now driving noware.

mmmikkke · December 30, 2005

Does that setup require premium fuel? And the dealer put in 87 octane?

If so, in my opinion, damage could have been done. If preignition was happening, on a brand new (not broken in) engine, that would not be good.

GM-Tech · December 30, 2005

Haven't even seen one yet.

fredg369 · December 31, 2005

Does that setup require premium fuel? And the dealer put in 87 octane?

If so, in my opinion, damage could have been done. If preignition was happening, on a brand new (not broken in) engine, that would not be good.

<{POST_SNAPBACK}>

I'll get it back to them after the new year and mention the gas thing to them.

The owners manual one part states....

If your vehicle has the 6.0L V8 engine,use premium unleaded gasoline with a posted octane rating of 91 or higher.You may also use regular unleaded gasoline rated at 87 octane or higher,but your vehicles acceleration may be slightly reduced,and you may notice a slight audible knocking noise,commonly refered to as spark knock......It goes on to say...if you use less then 87 you will hear a heavy knocking.Use a 87 octane or higher....if the heavy knock persist after using 87 get service soon

After switching to the higher octane should I give the computer a day or two to adjust?