Lesson Learned?

[Black Sun 5.0]

A few days ago I ran a post about a strange sound coming from the front of my engine area. I thought it may have been a pulley, maybe the alternator. Turns out, after I tested a theory, that I used too low an octane in my car. I filled up with 89 last weekend, around the time I noticed the sound. Last night, I capped off my tank with 3 gallons of 93 octane, the noise immediately disappeared. I only heard this sound at idle. Think upgrading to #24 injectors saved my engine?

 

[bobcatv8]

Been there, done that!
If I use anything but premium in my 170,000 mile bone stock '88 it pings like heck. Been that way since brand new!

 

[HISSIN50]

How does one get detonation only at idle. I dont think I could get detonation at idle, even if I had it in higher rpms. There is no load on the motor.

Anyhow, glad you seem to have remedied the issue.

 

[DMAN302]

How does one get detonation only at idle. I dont think I could get detonation at idle, even if I had it in higher rpms. There is no load on the motor.

Anyhow, glad you seem to have remedied the issue.

Seriously...just sounds a little strange, detonation at idle would be a first for me. Also glad you seemed to have stopped it...but I'm not sure it's remedied.

 

[Black Sun 5.0]

Like I said, higher octane killed the noise. I've had some fuel probs, also had cats that were burning up at idle that the shop told me was a lean condition. Ended up taking the cats out.

 

[kystang1889]

whats your timming set at? Do you have higher comp. ratio?

 

[darthcual]

You might have carbon build up that is making a higher compression and ur engine doesnt like the faster burning (lower) octane. Or previous owner feed him nothing but blondes, and now brunettes just wont due.