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Discussion Starter #1
Mazda forums suck with response time. Maybe you guys can help?

Just bought a 2004 Mazda 2.3L 5dr mtx 106,000mi, this week. It already has a very loud valvetrain (not injectors) that you can hear in the video too. The timing was advanced by previous owner, and there is a very nasty and frightening noise from the valvetrain that
STARTS AT 3,000rpm and ALWAYS ENDS AT 1,700rpm.

It is audible even on the freeway. The car has had a check engine light since I bought it; previous owner said it occurred after he advanced the timing. To clear anything up, he was/is not an idiot... definitely knew what he was doing. I have gone and put the timing back to stock, and when I reconnected the battery, it drove approx. 40 highway miles before the CEL came back on. My friend's 2008 2.3L is damn near silent compared to mine.

It is not the intake making noise. I even disconnected the butterfly valve on the manifold, and there is no change. Could it be the variable valve timing actuator? I've been researching this extensively... what part # is it?


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DTC P0606
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You wouldn't happen to know the CEL code would you?
Why was the previous owner advancing the timing and what did he do to accomplish this?
 

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Discussion Starter #3
You wouldn't happen to know the CEL code would you?
Why was the previous owner advancing the timing and what did he do to accomplish this?
I'm about to leave to get it scanned.

With the Mazda 3, you can advance the timing (not actually touching the cams or anything) by moving a sensor slightly.
From mazdas247.com:
Pros: Take advantage of higher octane, smoother acceleration, more hp/tq, ECU pulls back when engine knocking is detected
Cons: 1.6L has the sensor in a fixed position, Cost of using higher octane, Possible knocking from 87
Peak Power Gains: +6whp/3wtq (using 89 octane and timing vs. 87; your mileage may vary)
What you're basically doing is igniting the fuel mixture a little sooner by moving the slotted crank position sensor to advance the ignition timing. It will still be within factory specs (8° BTDC set at factory according to Service Manual, 10° BTDC according to Service Highlights- that info alone could be why some stock 3s are putting out slightly higher #s than others). This modification only deals with the ignition; the cam is not affected- therefore, the VVT operations/changes will still engage at the same rpms. While 87 octane works with this modification, those who have experienced knocking/pinging use 89 octane to compensate.

I advise you to reset the ECU so the timing curves/maps can be learned quicker. It will most likely stall just once while trying to find the new idle speed (it won’t stall again while it’s idle hunting the next time you reset the ECU). Some users report a slightly lower idle speed after doing this mod, so don't be surprised if it drops lower than you're used to. You might also want to add some fuel injector cleaner every few tanks if you’re using 89 or higher.

My observations on different octane after this mod:
I've tried running 87 and it didn't seem to accelerate as fast on the freeway (ECU possibly retarding back the timing to a "safer" level). Burned through 2 gallons pretty fast though. I feel almost no difference between 89 and 91 for my 3, but both allow me to get better performance and smoother/quicker acceleration at the cost of lower gas mileage compared to the 87.

Timing Advance + 89 octane dyno:
@3.5k: +2hp, 4tq
@4.5k: +3hp, 4tq
@5.5k: +4hp, 4tq
@6.0k: +5hp, 4tq
@6.5k: +5hp, 4tq
(end quote)
 

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Discussion Starter #4
P0012 Intake camshaft position timing - over retarded (bank 1)
P0011 Intake camshaft position timing - over advanced (bank 1)
P2004 Intake manifold runner control stuck open (bank 1)

codes I just got
 

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DTC P0606
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Based on your video and your codes, I'd say that noise is IMRC related. You probably already figured that out.
 

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Those are belt engines right? How old is the belt?

If I had to guess, I'd say it's the sensor itself since you have both 11 and 12 DTCs, but it could be simply an old belt or bad tensioner. Do you have any kickback- where the engine rolls slightly backwards after shutting off?
 
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