fullsmoke

Upon cold startup (engine has sat overnight), there is this one, very short squeak/chirp that only sounds when the engine fires up. I know it is not the air pump because I just had a failing air pump replaced. I know it's not pinging because I run 91 ocatane.

As I understand it, oil/grease on the belt will causes squeals/squeaks. I'm guessing it may be a little oil on the belt? If so, what's the best way to clean the belt?

FS

TeamRX8

iTrader: (25)

that's just the 12 volts hitting the hamster



.

MazdaManiac

iTrader: (3)

Ever notice it on light throttle application from idle?

It is actually a kind of knock as the ignition timing is shuffled around.
When you first start the motor, the leading plug is fired really early.

Its normal.

khoney

I'll have to disagree with MazdaManiac on this one, if you are hearing what I have heard since I got the recall reflash.

Definitely a chirping sound, not a knocking sound. I've had it for about 20K miles now. I never heard it prior to the reflash (which also made my car start harder, not better). Quite a while ago, I posted an audio clip of what I hear on startup (although due to sound quality, it's not as 'chirpy' as what I hear.

Here's the link:

https://www.rx8club.com/showthread.p...67#post1637967

mysql101

are you talking about a sound like this? (turn up the volume, it happens within the first two seconds):

http://video.google.com/videoplay?do...65511031036891

MazdaManiac

iTrader: (3)

Yes, it is a "chirp". That is what this kind of detonation sounds like.
Its a real quick "fingernails-on-chalkboard" kind of sound.

That's the one!

khoney

Yes, that sounds like it, although it sounds like you have a double-chirp

What's the horrible screeching sound? That's worse than fingernails on a blackboard!

khoney

So why have I never heard this in my 50K miles before the reflash? Not trying to be difficult, just trying to understand. If it's normal, then was my car 'not normal' for the first 50K miles?

BTW, I have friends at work with RX-8s. They don't chirp...

mysql101

WHAT?! You mean yours doesn't do that? Mine's been doing that since I changed to synthetic oil! OMG.

TeamRX8

iTrader: (25)

you can really hear it on most aftermarket intakes, unless I'm hearing a different kind of chirp, or maybe that's a whistle

mysql101

Yeah, there's a notice from mazda about customers complaining about a whistling noise - it basically says to assure the customer it's normal. It's caused by air going past a jet air mixing tube or something like that. I searched but couldn't find it

With the stock box, it's muffled to the point that I never noticed it. When you have an intake with a much more direct route to the outside, you can hear it fairly well.

My audio clip has 3 noises, the chirping at startup, the constant whistling, and the bov.

SmokeyTheBalrog

I also have a similar sound. But it's more metal-on-metal sounding.

fullsmoke

Hmm, this morning it did not chirp (maybe due to warmer weather). When it does, it sounds exactly like khoney's sound clip! The google video isn't exactly what mine sounds like. Ideas?

FS

OnRails

You know what? I had the same thing this morning when I started up. I have a stock intake. Since there are some many others doing it too I'm gonna say it is normal.

fullsmoke

Ahhh, another thing to add to the "normal" list

6speed8

[QUOTE=khoney]I'll have to disagree with MazdaManiac on this one, if you are hearing what I have heard since I got the recall reflash.

Definitely a chirping sound, not a knocking sound. I've had it for about 20K miles now. I never heard it prior to the reflash (which also made my car start harder, not better). QUOTE]

I agree. The latest Flash brought this sound and reduced fuel mileage.

OnRails

Well I don't see how it's really a problem or anything.

EDIT: I mean the chirp sound not the gas mileage.

map

This must be the canaries in a blender noise. It happens at the start and goes away once the blender is turned on :P

khoney

[QUOTE=6speed8]My sentiments exactly. I just want to know if there is something wrong with the car that the new flash has brought to the surface. My car takes a lot longer to start than before the reflash, so I'm thinking there is something that changed in the flash that works well if the car doesn't have a problem, and perhaps creates chirping and long starts if there's something wrong...

MazdaManiac

iTrader: (3)

I'll reiterate this for my fair audience at the "Short Attention Span Theater" - The "chirp" that is clearly recorded in the audio samples above is caused by a kind of detonation that occurs as the timing advance changes during the low RPM of start-up.

Often, you can hear this sound when you take off in first from an idle as well as the same thing is happening.

It is caused by the ignition timing and it is "normal".

The reason some people hear it and some don't is because of a number of factors (attentiveness being one of them), including the fact that, since this is a kind of detonation, some engines will be more sensitive to it than others.
It is not damaging because the load on the motor at that moment is extremely low.
The new flash may have increased the occurance of this by significantly changing the ignition timing. This may also lead to hard starts.
One of the most important factors in idle emissions is ignition timing. Mazda may have been trying to offset the increased emissions of increased oil injection by advancing the idle timing.

OnRails

Now you're just being paranoid.

6speed8

I can't see how it is detonation as it DOES NOT OCCUR when hot! It only makes the noise on the initial start in the morning. It does take longer to start (thankfully the new starter can handle that!).

Any NOISE that originally wan't there when new cannot be good!

Nubo

Add me to the list of people who get the "chirp" only after the last reflash. Engine starts with a lot more gusto now (once it does start). Sound to me like the engine is starting suddenly and with a big rush, and maybe the noise is from rpm rapidly overrunning the starter. Or maybe that's my imagination.

My engine is stock, and still have the old-style OEM 2004 starter.

As far as longer start, I chalk that up to the ECU now programmed to not deliver fuel for a short time during start, to avoid flooding and allow crank rpm to build up before making fuel available. I'll settle for a few extra cranks if it avoids no-start problems and/or fouling.

MazdaManiac

iTrader: (3)

Detonation has nothing to do with heat. It simply means combustion at the wrong time.
What is happening is the spark is so advanced that right as the engine starts to come up to speed, the combustion that starts at the trailing plug is actually trying to force the rotor backwards. It is the "fight" that you are hearing for that one revolution right before engine speed is high enough to sustain itself.

TeamRX8

iTrader: (25)