Can anyone describe the issue concerning pre-detonation or pinking. I know what it is - i just can`t tell if my 8 is doing it or not. I`m suspicious though....and somewhat concerned. I always run at least 93 Octane, sometimes 94. On acceleration in any gear, from about 2500 rpm to about 4000 rpm i get a light plinking noise, metallic rattle from the engine which goes away at higher rpms. It sounds very much like a conventional engine with a loose camshaft drive chain. That type of noise.

I have read all sorts of wierd and slightly potty sounding theories about pinking causing premature rotor tip seal wear etc, etc.

Anyone know about this subject? Any dealer experience? - my Mazda dealer tried to convince me that i was not using the right octane of gas which really pissed me off.

Yours hopefully - Tom

 

Ive gotta 2k5 6-speed and it does it as well. I notice it at the rpms you mentioned...and from about 6k - 6250k. It's got about 940 miles and I dont abuse my car. From what I hear, it's normal...

 

what you are hearing is the ports opening. Not pinging.

 

It's called pinging, not pinking. Take it to another dealership. Metallic sound from the engine (detonation) isn't good.

 

i have the same sound and i dont think its pinging; id like to hear somebody give a definitive explanation of what it is tho;

 

Here is another question. I notice that when I left off of the gas pedal my 8 sounds as if it slightly backfires. the performance has not taken a nose dive so far I just want to make sure it isn't too serious.

 

slight backfire is very common

 

Good I have had it to a dealership for routine maintenance and they have never said anything. I do have a GReddy SP2 with a high flow catalytic converter on it so the backfire is probably just pronounced a little more.

 

pinging on my 8 sounded like a pepsi can crushing, very painful sound. I was/will be again turboed don't know if that altered the sound or if yours would sound like that or not.

 

From everyone here, the slight pinging sound is the ports opening. Most notice it at 2-4k rpms....and around 6krpms. Also, the backfiring in a rotary is common.

 

Stop lugging your engine

 

whats lugging your engine?

 

Driving your car around with low rpm's. You should try to keep them above 3k.

 

I see, thanks for the info Brice. I usually shift at around 4-5krpms...and when cruising in 6th I stay at 3.5k - 4krpms.

 

what is the technical definition of lugging.. i get that sound too at low rpms... kinda of a grindy noise.. i think its in the tranny..... but not sure..

 

rubbish.

 

Why do you think that is rubbish?

 

When you let off the gas and have unburnt fuel in the exhaust system it is going to ignite and backfire. Another reason for backfires is a non-restrictive exhaust system, lets it breath much better.

 

because the engine is much more capable than you are giving it credit for. if you are just maintaining speed, ~1750rpm will do that just fine. if you are accelerating normally, 2k-3k rpm is more than adequate for that. in fact, the only time you need to go over 3k rpm is if you are accelerating hard or doing your daily redline run(s) to keep carbon deposits from building up...or going up a hill. hills negate everything i said

no, the car isn't a torque monster, but it makes more than enough for normal, daily driving, at rpms below 3k even. if you are experiencing dangerously low power below 3-4k rpm, then have your dealer inspect your coils.

 

You are correct, but if you want any sort of acceleration then you will need to drop it a couple gears from there and get going.

I don't know about you have to shift fast as hell to keep it below 3k when going through the gears, boy does it rev fast!

 

you do have a point, and it is very nice going ~45 in 6th, and dropping to 2nd :D
and it doesn't feel like i'm shifting through the gears all that quick. let it leisurely climb to 2.5k-3.5k rpms and then shift. repeat.

i said rubbish before because there are some people that honestly think the car is incapable of movement at anything under 3-4k rpm. i'm just trying to at least partially dispell this myth one thread at a time.

one person even said they have to rev to at least 3k rpm to launch in first or else it will bog.

 

I feel the same you do. It does have power below 2k, but sometimes it is nice to hear the 3-4k rotary hum.

 

i definately agree. my favorite sound is when the car is just cranked. it sounds different than when it is up to temp. its a great sound.

but there's a difference between "you have to stay above 3k rpm to have power" and "the engine is at its best at higher rpms".

 

i have given the answer several times and told which thread or linked to it in what must be dozens of threads. search my posts for sdais