CMP Timing Over Retard

jakembang

Member
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Mazda CX9 GT, 2009
I have had a Mazda CX9 GT, 3.7L, 2009, bought second hand with 87k mile. A couple of times I have had the CEL come on and off. Using a reader I get a P0012 & P0022 codes. Also there has been an abnormal knocking sound from the engine right side before the last oil change, with intermittent retarded acceleration. I changed the oil and resetted the CEL, but no change. I am not a mechanic but an enthusiast. Please can someone enlighten me on the possible issues? Thanks in advance.
 
Do you know if anyone worked on the car before? like maybe changed out the water pump and didn't align the marks correctly for the timing. You shouldn't be having that problem unless someone opened up the engine and may have worked on it and didn't properly put it back together.
 
Do you know if anyone worked on the car before? like maybe changed out the water pump and didn't align the marks correctly for the timing. You shouldn't be having that problem unless someone opened up the engine and may have worked on it and didn't properly put it back together.

Thanks for the response...I cant say about the maintenance history since it was bought from a dealer. Do you suggest I get the timing rechecked? And the noise? Please is it related to that too? Thanks in advance
 
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Thanks for the response...I cant say about the maintenance history since it was bought from a dealer. Do you suggest I get the timing rechecked? And the noise? Please is it related to that too? Thanks in advance

Sorry for the late response.

Your problem is most likely a failed or clogged VVT solenoid or VVT actuator. A lack of regular oil changes can clog up these devices.
When a VVT dies, they make a knocking/rattling sound during acceleration and throw the codes you mention.

You can easily check the solenoids for electrical values (should be 5-15 ohms across the 2 pins) as they stick out of the valve covers, but checking the actual solenoids for clogs will require you to pull the valve covers. The actuators are held down by a small bolt and then slide out.

Checking/changing the VVT actuators themselves is a much bigger job involving pulling both the valve covers and timing chain cover. If the vehicle has not yet had its water pump replaced, you should consider doing that at this mileage anyway.

Check out my DIY here and find the section on checking the VVT solenoids for the electrical specs and more info on what's involved in the bigger job.

https://www.mazdas247.com/forum/showthread.php?123860369-CX-9-Water-Pump-Replacement-DIY-Guide

A quick test is to disconnect both VVT solenoid wires and see how it runs. If it smooths out (may still throw codes) then it's likely one or both VVTs. You don't actually need VVTs working to run the vehicle, but it change the power and response characteristics. if you want to run without them, disconnect both.
 
Sorry for the late response.

Your problem is most likely a failed or clogged VVT solenoid or VVT actuator. A lack of regular oil changes can clog up these devices.
When a VVT dies, they make a knocking/rattling sound during acceleration and throw the codes you mention.

You can easily check the solenoids for electrical values (should be 5-15 ohms across the 2 pins) as they stick out of the valve covers, but checking the actual solenoids for clogs will require you to pull the valve covers. The actuators are held down by a small bolt and then slide out.

Checking/changing the VVT actuators themselves is a much bigger job involving pulling both the valve covers and timing chain cover. If the vehicle has not yet had its water pump replaced, you should consider doing that at this mileage anyway.

Check out my DIY here and find the section on checking the VVT solenoids for the electrical specs and more info on what's involved in the bigger job.

https://www.mazdas247.com/forum/showthread.php?123860369-CX-9-Water-Pump-Replacement-DIY-Guide

A quick test is to disconnect both VVT solenoid wires and see how it runs. If it smooths out (may still throw codes) then it's likely one or both VVTs. You don't actually need VVTs working to run the vehicle, but it change the power and response characteristics. if you want to run without them, disconnect both.

Thanks so much Thaumaturge for this great assistance...I think this is all I needed. I will be back home from work on 25th and will let you know how it all went.

I have gone through the DIY guide attached and I must really commend you for the details provided, wow.....

Many thanks, Jake
 
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