Quick chirp/squeak
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From: Florida
Originally Posted by MazdaManiac
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.
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.
How come the car did not do this when new, and only AFTER the latest flash, which seems to have not made any improvement.
I am serirously trying to understand how this noise, the longer start and the reduction in fuel economy is "nothing to be concerned with". (can you use the term 'fuel economy' when discussing the RX-8? - lol)
FX8TED on my RX-8
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From: San Antonio
Originally Posted by MazdaManiac
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.
Originally Posted by MazdaManiac
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".
It is caused by the ignition timing and it is "normal".
Originally Posted by MazdaManiac
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.
It is not damaging because the load on the motor at that moment is extremely low.
Originally Posted by MazdaManiac
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.
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.
I appreciate your input on this (except for the 'attention span' thing), and I'm just trying to get a better technical understanding of why some cars chirp and others don't. For instance, my car has 72K miles on it - could a coil pack be going bad, causing the ECU to compensate in such a way that the car chirps? Stuff like that is what I'm wondering about...
FX8TED on my RX-8
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From: San Antonio
Originally Posted by 6speed8
I understand detonation, But then what you are saying is that the timing is REALLY advanced during a COLD START? That doesn't make any sense, since it does not happen when 'hot'. IS the timing not as advanced or even retarded when hot?
...
...
Originally Posted by khoney
OK, so you've finally answered my question... "the new flash significantly changed the ignition timing".
Originally Posted by khoney
Maybe now you can answer another one. Two reflashed RX-8s are sitting next to each other in the parking lot - both engines are cold. One chirps loudly on startup, the other doesn't make a peep. That would indicate a significant timing difference between the two, would it not? What are the possible causes of this timing difference?
FX8TED on my RX-8
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From: San Antonio
Sorry, not seeing it... as well as being inattentive and having a short attention span, I must be dumb as a post, too. Can you please point it out for me?
Never mind, I guess this is the 'sensitivity' thing.
So, in a nutshell, if your car chirps, it's normal. If your car doesn't chirp, it's normal.
OK, I can rest easy now...
Never mind, I guess this is the 'sensitivity' thing.
So, in a nutshell, if your car chirps, it's normal. If your car doesn't chirp, it's normal.
OK, I can rest easy now...
Last edited by khoney; Feb 24, 2007 at 11:50 AM.
FX8TED on my RX-8
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From: San Antonio
Originally Posted by mysql101
I'm buying a gallon of WD40. Will post back my results once I'm done.
Let me know where to apply it. Should I use a hose-end sprayer? Maybe it'll get rid of my clutch squeaking, too!
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Joined: Apr 2004
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From: USA
Get a Wagner Power Painter for $30. Then have at it. By the time you're done and test it out, you will not notice any squeaking!
Of course, your engine might be on fire... but that's something we can address when we get to it.
Of course, your engine might be on fire... but that's something we can address when we get to it.
FX8TED on my RX-8
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From: San Antonio
Originally Posted by mysql101
WHAT?! You mean yours doesn't do that? Mine's been doing that since I changed to synthetic oil! OMG.
FX8TED on my RX-8
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From: San Antonio
Problem fixed!
Well, I managed to make my chirp go away. I replaced all 4 ignition coils and installed Magnecor plug wires on Saturday. Results:
1) No more chirp on startup.
2) Startup is about twice as fast as before.
3) Idle is much smoother. The car used to shake when the AC compressor kicked on, now it desn't even hiccup.
4) General power delivery is much smoother - I honestly feel like I'm driving a new car.
Now, one thing I have to say is that I can't definitively say it's the plugs and coils that made the difference. I was most of the way through the install and pulling off the last plug wire, and it seemed like I didn't have to pull as hard. Perhaps it was loose - I'm not sure. But if it was, it would have had to have been that way for a long time (at least 20K miles).
Unfortunately, I can't enjoy my 'new' car for a while. I got T-boned this afternoon and received significant damage to the driver's side.
1) No more chirp on startup.
2) Startup is about twice as fast as before.
3) Idle is much smoother. The car used to shake when the AC compressor kicked on, now it desn't even hiccup.
4) General power delivery is much smoother - I honestly feel like I'm driving a new car.
Now, one thing I have to say is that I can't definitively say it's the plugs and coils that made the difference. I was most of the way through the install and pulling off the last plug wire, and it seemed like I didn't have to pull as hard. Perhaps it was loose - I'm not sure. But if it was, it would have had to have been that way for a long time (at least 20K miles).
Unfortunately, I can't enjoy my 'new' car for a while. I got T-boned this afternoon and received significant damage to the driver's side.
Originally Posted by khoney
3) Idle is much smoother. The car used to shake when the AC compressor kicked on, now it desn't even hiccup.
FX8TED on my RX-8
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From: San Antonio
Originally Posted by chickenwafer
Exessive vibration has to do with a recall Mazda issued due to a collapsed motor mount.
Looks like I probably won't have to worry about it anymore - I think they're going to total the car...
FX8TED on my RX-8
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From: San Antonio
Originally Posted by MazdaManiac
Bummer about the crash.
Coils are important.
Your Magnacores are BS, but they probably wont hurt anything.
Coils are important.
Your Magnacores are BS, but they probably wont hurt anything.
It's a shame I only got to use my new gear for a day
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ig coils plugs et al
Just replaced the coils in my '04 and all the chirps and bad starts (cold and hot) have gone - starts on the nose. Lil' lumpy on hot idle. By the state of the coils I am assuming the plugs are bad as well. Have a new set of NGK's. Plan to replace them Thursday (2nd Aug '12). Will post back on that.
Will post pics of of new vs old plugs if wanted. +old coils, but didn't bother to get the order - soz.
She's a 2004 - had her 6 months. 44000 miles now, got her at 38ish. Going by the state of the coils, never been looked at, guessing the plugs are the same. Rest of car is uber.
Will post pics of of new vs old plugs if wanted. +old coils, but didn't bother to get the order - soz.
She's a 2004 - had her 6 months. 44000 miles now, got her at 38ish. Going by the state of the coils, never been looked at, guessing the plugs are the same. Rest of car is uber.
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