Silver Ecstasy
Member
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- 11 MS3 Sport
All I use is 93 octane. What would that exactly feel like? I haven't experienced any problems with my car really in terms of engine or power.
Knock sensor danger zone?
- Thread starter AutoEuphoria
- Start date
AutoEuphoria
Member
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- '08 CPW Mazdaspeed 3
Audible warning is just a little click, basically.
you wont ever "feel" knock. if the knock is bad enough, you will feel the ecu retarding the timing. if you are able to feel that you are down on power, then you have WAY TOO MUCH knock.
knock sounds like marbles rattling in a can.
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AutoXRacer
Member
Knock doesn't feel like anything...you might hear it...but definitely won't feel it... Thats why you need instrumentation to keep an eye on it.
Speed3Rookie
Member
Silver Ecstasy
Member
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- 11 MS3 Sport
So knock is basically something that shouldn't happen basically, and when it does, the ECU pulls power to keep things safe, correct?
AutoXRacer
Member
Oh, I've heard that...but only if my windows are up and my radio off...
Its really faint...
Got it...I thought maybe I had missed a feature... I was thinking more like a loud obnoxious beep... (lol2)
Thanks!! (2thumbs)
AutoXRacer
Member
Yeah, knock should no be happening unless you put in bad/low grade gas... But, in the MS3, knock seems to be present and no one has figured out how to eliminate it (I'm talking about part throttle knock). Regarding WOT knock, you need a Standback to tune it out...or add octane booster in your tank.
When the ECU senses knock, it will retard the timing...worst the knock is more timing is pulled. Less timing you run, less power you have. Pulling the timing cools down the cylinder temps and lowers pressures, thus protecting your engine.
But the catch is, is that when the ECU senses knock, its already happened and if its bad enough, it will be too late to protect your engine.
Silver Ecstasy
Member
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- 11 MS3 Sport
Weird, I had no idea! Surprised that this hasn't been covered more often, or maybe I have somehow managed to miss it..
Speed3Rookie
Member
Actually the screen will flash the alert color of your choice. I have my background color the same as the dash light and my alert color is green.
AutoXRacer
Member
Its been covered a lot...but not in this website. This is not a very technical forum per say...
Silver Ecstasy
Member
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- 11 MS3 Sport
I've noticed that they sure talk a lot about engines on the other forum. Whether it's casual, or because of causes for concern (engine ailments, things like that).
AutoXRacer
Member
If you go to the ECU sub forum, you'll find lots of threads on Knock.
I registered 7.8 knock for a brief moment on the way to work this morning. Holy s***!
I didn't hear the knock or feel power loss. I was just cruising up a slight incline in 5th gear at about 45MPH.
The odd thing is, this one spot of my drive seems to be where I get knock warnings. I'd say with the current weather I'm seeing readings of around 6.0 - 7.0 for a brief moment every other day or so.
I didn't hear the knock or feel power loss. I was just cruising up a slight incline in 5th gear at about 45MPH.
The odd thing is, this one spot of my drive seems to be where I get knock warnings. I'd say with the current weather I'm seeing readings of around 6.0 - 7.0 for a brief moment every other day or so.
SuperStretch18
Member
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- '07 CX-7 Sport, Black on Black; '04 Mazda3s
Is this point pretty early in your commute? I've found that if I get on the throttle too much in the first five minutes or so of driving, that's when i see the worst knock. I usually have to give it a couple of minutes after it reaches a good operating temp...
AutoXRacer
Member
45MPH on 5th gear on an incline...? Isn't that a little too much load on such a tall gear... I would imagine 4th would be more appropriate.... (hmm)
AutoEuphoria
Member
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- '08 CPW Mazdaspeed 3
Just set up the DH to monitor engine load...that should help you a bit 
AutoEuphoria
Member
- :
- '08 CPW Mazdaspeed 3
If your engine load is going up, but you're not really accelerating, you need to switch to a lower gear.
As far as fuel pressure, I'd just watch it for a couple of days or log it a few times and see what you're normally running, then watch to make sure it doesn't drop much past the normal values.
Speaking of normal values, anyone have any idea how that feature works, or how to set it up? I thought it said it automatically figures out the normal range and will change the display if it drops out of the normal range, but that doesn't seem to work for me.
As far as fuel pressure, I'd just watch it for a couple of days or log it a few times and see what you're normally running, then watch to make sure it doesn't drop much past the normal values.
Speaking of normal values, anyone have any idea how that feature works, or how to set it up? I thought it said it automatically figures out the normal range and will change the display if it drops out of the normal range, but that doesn't seem to work for me.
