Hello, hopefully somebody with a similar issue can chime in
or offer some advice on how to further proceed. I'm working
on a 2012 Ford Mustang 5.0L V8 and I'm experiencing a P0024
(exhaust camshaft position timing over advanced bank 2). I
went through the basic diagnosis tree per Ford and was led
to replace the camshaft VVT phaser assembly.
- Oil pressure hot was 10-12psi idle hot (spec is 10-15psig
idle hot).
- VVT monitor bank 2 exhaust phaser stuck at or close to
zero degrees.
- Under WOT, phaser would advance full to around 40 degrees
and be steady until reduced throttle.
- Phaser is not variable like the others are, computer is
commanding it proper.
- Engine is very quiet, no noise or abnormal chatter.
Fast forward to today, when pulling apart the engine I
noticed a few things. The oil pump is an aftermarket Melling
pump (standard) and I didn't see any markings on the timing
components other then the 4 camshaft phasers. The phasers
are OEM but not sure about the chains, guides or tensioners.
I replaced the bank 2 VVT phaser with Ford OEM as well as
the filter behind the camshaft. Also removed the oil pump to
verify clearances and replaced the pickup o-ring.
NOTE: When compressing the secondary tensioner by hand to
pull the phasers forward and the chain off the tensioner
guide, it wouldn't compress. Lots of pressure on the chain.
It took a heavy amount of pressure by hand until it became
free. Bank 1 didn't have this issue. After compressing the
tensioner numerous times, it didn't appear to be an issue.
When I had the timing components removed, I blew shop air
through the large opening in the camshafts where the filters
are located. It did not blow easily. Seemed to be a fair
amount of resistance. Not sure what is normal however since
I didn't remove the phasers and try the same on the other
bank. Also from my understanding, the first generation
coyote engines have oil restrictors built into the cylinder
head gaskets.
Finished up bolting everything together and went for a test
drive. Phaser operation seemed to be back to normal. It was
variable and obtaining the desired position. I did 2 WOT
runs and that's when the problem came back. PCM threw code
P0024 once again and phaser operation is no longer variable
and going to desired position per PID.
I'm leaning toward an oil restriction somewhere in the
engine but I really am not sure. Also not sure if I blew
shop air through the correct area to hopefully blow any gunk
out of the passages. Engine oil upon arrival was very clean.
I added .5 quart ATF and it still was clean when I drained
it. No buildup under the valve covers. I believe the
secondary tensioner is oil pressure controlled as well, but
not sure why it was stuck. My thoughts are oil pressure
built up in the head past the restriction and caused it to
not relieve pressure. Pressure must be bleeding off though
since the exhaust phaser will go back to zero degrees.
Not sure where to start. Thought about doing an engine flush
but I don't believe this will necessary make any difference.
I could always tear down the engine but I'm not sure if I
could find what would be causing a restriction. Maybe there
isn't even a oil restriction, but I'm exhausting my ideas.
Any help is appreciated.
or offer some advice on how to further proceed. I'm working
on a 2012 Ford Mustang 5.0L V8 and I'm experiencing a P0024
(exhaust camshaft position timing over advanced bank 2). I
went through the basic diagnosis tree per Ford and was led
to replace the camshaft VVT phaser assembly.
- Oil pressure hot was 10-12psi idle hot (spec is 10-15psig
idle hot).
- VVT monitor bank 2 exhaust phaser stuck at or close to
zero degrees.
- Under WOT, phaser would advance full to around 40 degrees
and be steady until reduced throttle.
- Phaser is not variable like the others are, computer is
commanding it proper.
- Engine is very quiet, no noise or abnormal chatter.
Fast forward to today, when pulling apart the engine I
noticed a few things. The oil pump is an aftermarket Melling
pump (standard) and I didn't see any markings on the timing
components other then the 4 camshaft phasers. The phasers
are OEM but not sure about the chains, guides or tensioners.
I replaced the bank 2 VVT phaser with Ford OEM as well as
the filter behind the camshaft. Also removed the oil pump to
verify clearances and replaced the pickup o-ring.
NOTE: When compressing the secondary tensioner by hand to
pull the phasers forward and the chain off the tensioner
guide, it wouldn't compress. Lots of pressure on the chain.
It took a heavy amount of pressure by hand until it became
free. Bank 1 didn't have this issue. After compressing the
tensioner numerous times, it didn't appear to be an issue.
When I had the timing components removed, I blew shop air
through the large opening in the camshafts where the filters
are located. It did not blow easily. Seemed to be a fair
amount of resistance. Not sure what is normal however since
I didn't remove the phasers and try the same on the other
bank. Also from my understanding, the first generation
coyote engines have oil restrictors built into the cylinder
head gaskets.
Finished up bolting everything together and went for a test
drive. Phaser operation seemed to be back to normal. It was
variable and obtaining the desired position. I did 2 WOT
runs and that's when the problem came back. PCM threw code
P0024 once again and phaser operation is no longer variable
and going to desired position per PID.
I'm leaning toward an oil restriction somewhere in the
engine but I really am not sure. Also not sure if I blew
shop air through the correct area to hopefully blow any gunk
out of the passages. Engine oil upon arrival was very clean.
I added .5 quart ATF and it still was clean when I drained
it. No buildup under the valve covers. I believe the
secondary tensioner is oil pressure controlled as well, but
not sure why it was stuck. My thoughts are oil pressure
built up in the head past the restriction and caused it to
not relieve pressure. Pressure must be bleeding off though
since the exhaust phaser will go back to zero degrees.
Not sure where to start. Thought about doing an engine flush
but I don't believe this will necessary make any difference.
I could always tear down the engine but I'm not sure if I
could find what would be causing a restriction. Maybe there
isn't even a oil restriction, but I'm exhausting my ideas.
Any help is appreciated.