Ok, so twice in the past month I have been pulling away from a stoplight and all of a sudden I hear this horrible metalic noise coming from the engine bay, the car feels like it has pulled all sorts of timing and loses power. Get to the next stoplight and take off, everything seems to be fine again. Is it detonation? I have run 87 octane in my car for the past 16k miles, never had this problem till now, since I have had the recall flash done, and new plugs put in. I have 35k on my car now and have not had any engine problems thus far. Car idles fine, is very smooth other than these 2 times. The first time it was around 80 outside, and the second time it was around 60. No CEL.

Also, if it matters I have been driving to a new job for the past 3 months, 110 miles round trip on the highway, 5 days a week, with work being about 2000 feet above sealevel and home being around 500 feet above sealevel. Both times it has happened at home after being up in the higher elevation.

Give me your thoughts. The obvious thing I am going to do is put 93 octane in to see if that keeps it away, but from what I understand the "T" flash just changes oil injection, is that correct?

 

Dont think its the fuel youre using....Intermittent noises.

 

It's not just a random noise, it is the engine having some trouble of some sorts when this happens. If more info is needed please let me know, I tried to get all of the details into the first post.

 

Just an update, I have put nothing but 93 octane in it since posting and the problem has not repeated itself. I guess it was detonating with the 87 octane in it, granted it has been a little cooler since I experience the issue. I am not sure what was done in the recall flash other than more oil injection but it has made my car not able to have 87 octane run through it. Could the new plugs have anything to do with it?

 

I have the same problem with 87-reg. The first 20k it ran fine on it, now I have to run prem-91. I have added a can of Chevron-Tectron to the last 2 tanks of prem fuel. I hope to remove the carbon build-up caused by the rich mixture to save the emission equipment. Mine is a 04-A/T with 30k on it now. Have you heard of this Mod that might help. Let me know if it helps. Mine is worse the hoter it gets.

https://www.rx8club.com/showthread.p...le+body+bypass

 

I have had the same thing on low octane - it is definately detonation causing the knock sensor cut fuel (or whatever it does) .
I ran low octane for a year with no problem-then a combination of things :
piggyback tuned for leaner mixtutre
warm day
lots of sitting around at idle
then fast take off -
bam - massive detonation . It makes sense when you think about it .