05 Mustang Gt Diagnosis Help....hard Fix!

Not my theory, but that of the author. Looks like being a mechanic and putting a lot research into this you were able to circumvent the need for a tune. You have the equipment and knowledge to figure all this out - more power to you. I already had a tuner when I installed my deletes and Brenspeed adjusted the tune I already had and it ran great for 5 years with the charge motion motor removed. I removed the deletes when I installed my Saleen VI s/c this year. If someone already has a tuner and their tune can be updated without cost and it works great that should be ok as not everyone goes through the research you have. But, if you can help others avoid a costly tuner and tune, I'm sure people will definitely be interested in that.

Oh, BTW shortly after I purchased this Mustang in 2006 and after a long cruise, it would often buck and stutter on acceleration. I'm not saying this was your problem, but Ford replaced my fuel pump under warranty and that problem was eliminated.

Just recently I started to get a P0340 code, so I've got a New PA Performance alternator coming. Car runs fine just throws a code.
 
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If you would like I can assist u with the p0430 code, I have the test procedure for that! The alternator emf issue is a common cause for this but seeing as u have replaced that I would try pinpoint testing vvt solenoids and cam phasers. As for the charge motion plates I left the housing and actuator in, just drilled out the rivets holding the plates in. I assumed the only purpose for them was fuel economy and emissions but I will refer to alldata to tell me the exact purpose for them!
Had my fuel pump replaced under warrantee already, my car only has 39k miles on it to date and I got it with 7 miles straight from Detroit.
Let me know if u would like assistance
 
I just started having this problem. My 05 GT Manual trans started "stuttering" when I accelerate from a low RPM. I took it to a computer diagnostic shop and he is unable to figure out the cause. His computers found that the engine is running 68% rich.

The only error code I've gotten was the P0012. My only mods are a CAI and tune by brenspeed. Oil changed, spark plugs changed, fuel filter changed.

My wife was in a rear end "bumper tap" collision a few months prior to this problem.

Anything to the previous post regarding the alternator?
 
Ok.....po012 is a camshaft code. Here is the possible causes and the diagnostic procedure. From experience I'm willing to bet you have a variable valve cam phaser solenoid that is clogged or stuck closed/open! There is one per bank (in front of each valve cover.... in the valve cover itself) I would replace them both as it is not a difficult job . here is some info to look over, i am still looking for the vvt solenoid pinpoint test procedure. the altornator could cause the problems your having but read this first.
 

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if you have good oil pressure and change your oil regularly and have had your altornator replaced i would make a very educated guess that the vvt solenoids are stuck or clogged with oil. make sure your tune is not preventing your solenoids from directing oil to the cam phasers. cam phasers are what determine your cam timing. your solenoid is stuck open allowing continous oil flow to the phaser inturn fully advancing your cam timing. you do not need to remove the valve covers to change the phasers, just need a flat head screwdriver and a 8mm 1/4in socket with a ratchet and extention. if you think you can do this yourself i will guide you through the steps to verify that the solenoid is at fault. first thing i would do is to research removal and replace procedure to see if its something you feel comfortable doing and if you do...............SWITH THE SOLENOIDS FROM SIDE TO SIDE! put the left on the right and vice versa. you may need new seals if you dammage the old ones taking them out. if the fault code changes to the other bank (side) then you know your phaser is at fault! let me know if u think u can do this and i will give u a step by step procedure. got to run, late for work! peace -M
ike
 
If you would like I can assist u with the p0430 code, I have the test procedure for that! The alternator emf issue is a common cause for this but seeing as u have replaced that I would try pinpoint testing vvt solenoids and cam phasers. As for the charge motion plates I left the housing and actuator in, just drilled out the rivets holding the plates in. I assumed the only purpose for them was fuel economy and emissions but I will refer to alldata to tell me the exact purpose for them!
Had my fuel pump replaced under warrantee already, my car only has 39k miles on it to date and I got it with 7 miles straight from Detroit.
Let me know if u would like assistance

Haven't installed it yet but will see after that. Right now it runs great except for a failing alternator (it seems). The SCT Xcal2 I've had for 7 years seems to have packed it in. Possibly from this P0340 code or failing alternator. Can't load tunes and am researching that.
 
The XCal2 was 7 years old, obviously warranty was long gone. I took it apart and saw that the green wire on the obdII cable had broken off the fecp solder point. Re-soldered it and now the loader works again. If anyone has the "Turn key on Do Not Start" flashing until the power up times out, this may likely be the problem. The small wires are crammed and twisted and easily broken off the board.
 
Are you still having the same problem.....shuttering at low speed acceleration??? You said you had a code p0012 and a p0340, is this correct? What are your current codes? You also mention your altornator is failing, have you had it tested? What makes u think it's failing? Did you notice the problem after you changed your oil.....did you use a 5w20 synthetic or synthetic blend and have you checked to make sure it's full? When you say 68% rich, is that both banks or just one? 68% is not bad...my car is usually running around that too. If you can answer all or most of these questions I should be able to point you in the right direction. It sounds like your cam phaser/phasers are fully retarted. There are multiple ways for this to occure hence all the questions. I'm guessing you have a stuck open cam phaser solenoid on bank 1!
 
Are you still having the same problem.....shuttering at low speed acceleration??? You said you had a code p0012 and a p0340, is this correct? What are your current codes? You also mention your altornator is failing, have you had it tested? What makes u think it's failing? Did you notice the problem after you changed your oil.....did you use a 5w20 synthetic or synthetic blend and have you checked to make sure it's full? When you say 68% rich, is that both banks or just one? 68% is not bad...my car is usually running around that too. If you can answer all or most of these questions I should be able to point you in the right direction. It sounds like your cam phaser/phasers are fully retarted. There are multiple ways for this to occure hence all the questions. I'm guessing you have a stuck open cam phaser solenoid on bank 1!
@805mustang, I recently purchased an 08GT with high miles(125,000 commuter miles) I have code p0022, occasionally shudders at low speed. Started after a recent oil change with Castrol full synthetic 5w20, at least that is what the lube shop charged me for. I would appreciate any suggestions.
 
Yea I think I can help you out with that. If you can answer all questions I ask, I would appreciate that. It will help me to help you. That said please answer these.
What is your mechanical background?
Is the code p0022 still present and is this the first time for this code?
When you say shudder do you mean on acceleration or idle, at highway speed or in town driving? can you describe it in more detail?
Have you checked your oil after you had it changed and how was it?
Did the problem/issue your having start immediately after your oil change?
If u can answer my questions I will be able to more accurately diagnose your car!
From what I know by reading your post I suspect you have an issue with either your (variable cam timing) VCT solenoid or your camshaft phaser on bank 2 (drivers side)
 
recently my car has been acting up, let me start by saying i have been a mechanic for 8 years and am good at diagnosing and repairing cars......but this is a different story as u will read......... I have been driving a 2005 mustang gt with 35000mi....accessories are CIA (says it does not require a tune) wheel spacers, full boy racer body kit w/ duck tail instead of the wing, modified mufflers (cut them open and hollowed them out).....was chipped until i was in a fender bender.....not bad, no airbags, no dammage to engine at all i drove away and car was fine for months.....i recently put chip back in to see if that was the problem but no difference. oh by the way it is a chip not a tune!!! best of all i took the manifold runners out and drilled the rivits that hold them to the shaft. there is one per cylinder and they are designed to stay closed until 2750 rpm then they go wide open. thats why the 05-09 mustangs would lag until u hit 2800-2900rpm then it really pulls. taking them out was the biggest power gain so far. more noticeable than the chip and cia!!!!!!! no engine light and passes Ca smog test no problem.....if you do this you will love the results! write me if u want to know how.
ok, now for the issue at hand. my car has gradually been running rougher and rougher. idles fine and accelerates fine. drives good when its could and drives good warm! it will only occur one time a day at the same distance and the same driving conditions. same temperature same speed. no engine light and no other issues. i will be driving from home, about a quarter mile to the freeway on ramp and cruise at 70 mph, give or take a few,. i will make it about a 2.5 miles and it will buck and stumble. it will buck and stumble maybe 4 or 5 times within 1 mile and or about 1 minutes of driving then it goes away!.....I have a genisys evo 4.0 and can view live data, codes, mode six, component tests, pending, misfire data, sensor data and repair info and i cannot find anything too far out of value, nothing has tested bad and nothing has changed for the last year..........interest yet. the problem i just described happened 3 days in a row....all the exact same. now for the last 2 days i notice it runs rough at 1600 to 2500rpm and only in neutral but fine under load and fine on hard acceleration and idle. still no codes or info saying anything is wrong and sensors read good, all that seem important and that i can monitor.....and there are a lot!
does anyone have any ideas, i dont even know where to start. checked throttle body; clean, checked oil, full and clean; added 8 gallons of shell premium to almost empty tank (was running 87); no difference. new air filter; same! disconnected battery for(i know, overkill) 7 hrs; no change. i do not see a problem but i can feel it! im going to break out the scope tomorrow does anyone know how to approch this? anyone have a similar problem? does anyone have a discription of tsb's? wiring diagrams? HELP!!!!!!!!
 
Fuel filter?
Hey Jason do you have a close to stock mustang gt? Could I compare my live data readings to yours, if you have a scantool that is? I know why the hesitation occurs but it will buck maybe 4 or 5 times when the car goes from cold to hot, I.e. when the thermostat opens up! I am having slightly high readings on oil temp sensor when the car is cold but seems to be fine when the car is warm too! Don't know if that is an issue either. Does your oil temp read higher than your air temp, ect and cylinder head temp before you start the car for the first time after sitting overnight? Thanks -mike

Hey 805:
Sorry for the darkness. Luckily all my problems are mechanical and occur with a high mileage car. My GT is all stock and is running strong in LA traffic for a car with 146,000 miles. Replacing the alternator fixed the engine light-left&right bank variable cam timing issues. Reader is a basic OBD III. Only issues are little missfires at cold idle.
 
Yea I think I can help you out with that. If you can answer all questions I ask, I would appreciate that. It will help me to help you. That said please answer these.
What is your mechanical background?
Is the code p0022 still present and is this the first time for this code?
When you say shudder do you mean on acceleration or idle, at highway speed or in town driving? can you describe it in more detail?
Have you checked your oil after you had it changed and how was it?
Did the problem/issue your having start immediately after your oil change?
If u can answer my questions I will be able to more accurately diagnose your car!
From what I know by reading your post I suspect you have an issue with either your (variable cam timing) VCT solenoid or your camshaft phaser on bank 2 (drivers side)
I don't know the car's mechanical history prior to me buying it in July. No I have not checked oil yet.Will do that in the morning.It shudders and runs rough at or near idle. Issue is intermittent I think it was pretty much very shortly after the oil change.
 
Is the engine light still on? Code p0022?
What is your mechanical skill level? Are u capable of testing and replacing parts?
These cars must have the correct weight and level of oil, it is extremely important since they use oil pressure and flow to adjust camshaft position! If your oil is low I would try adding 5w20 synthetic oil until it is at the proper level. If it is not low I would recommend having it changed again. Personally I would not take it to a quick lube shop, take it to either a respected repair shop or the dealership. Use only the OEM oil filter (motorcraft) and a name brand 5w20 full synthetic oil. Even the incorrect or inferior oil filter could cause problems. Let me know what you find after you check your oil and or have it changed!
 
Is the engine light still on? Code p0022?
What is your mechanical skill level? Are u capable of testing and replacing parts?
These cars must have the correct weight and level of oil, it is extremely important since they use oil pressure and flow to adjust camshaft position! If your oil is low I would try adding 5w20 synthetic oil until it is at the proper level. If it is not low I would recommend having it changed again. Personally I would not take it to a quick lube shop, take it to either a respected repair shop or the dealership. Use only the OEM oil filter (motorcraft) and a name brand 5w20 full synthetic oil. Even the incorrect or inferior oil filter could cause problems. Let me know what you find after you check your oil and or have it changed!
Yes I am reasonably mechanically inclined. From my research I am comfortable taking on this should I need to replace solenoid. Haven't researched phaser replacement yet though I don't normally go to lube shops but circumstances left that as the best option at the time. I usually do maintenance stuff myself. I am busy with Army Reserve training all weekend. Will change oil and filter Monday with full synthetic and quality filter.
 
Is your engine light on? Do u have a scantool u can use? If you don't have one and the light is still on, stop by autozone or oriellys and they will check the code and clear it for free. Write down any codes that are present. If the problem still exists after you change your oil and filter and clear the light I will guide you through the steps to correctly diagnose the issue.
If you have time to add a detergent to your oil to break down any sludge before you have your oil changed I would do that. Even automatic transmission fluid will work and it's ok if it's a little over filled since it will only be for a few days.
 
Is your engine light on? Do u have a scantool u can use? If you don't have one and the light is still on, stop by autozone or oriellys and they will check the code and clear it for free. Write down any codes that are present. If the problem still exists after you change your oil and filter and clear the light I will guide you through the steps to correctly diagnose the issue.
If you have time to add a detergent to your oil to break down any sludge before you have your oil changed I would do that. Even automatic transmission fluid will work and it's ok if it's a little over filled since it will only be for a few days.
Yes, the MIL is still on. I have the U-scan device with app on my phone. Oil level is good. Will add detergent after end of duty day this evening and will change oil in a fee days to allow it time to work. Will update you after oil change as to fixed or issue continuing. Thanks much . I appreciate your time and help very much.
 
Not a problem.....I enjoy sharing knowledge. Keep me updated. I have a feeling your VCT solenoid will be the root cause of your problem but I cannot say for sure until we get proper lubrication. I will help guide u through the test procedure for the solenoid if the problem exists after you change your oil.
 
Hey Jason do you have a close to stock mustang gt? Could I compare my live data readings to yours, if you have a scantool that is? I know why the hesitation occurs but it will buck maybe 4 or 5 times when the car goes from cold to hot, I.e. when the thermostat opens up! I am having slightly high readings on oil temp sensor when the car is cold but seems to be fine when the car is warm too! Don't know if that is an issue either. Does your oil temp read higher than your air temp, ect and cylinder head temp before you start the car for the first time after sitting overnight? Thanks -mike

Sorry for the darkness, 805.
Scan tool? It's a simple Accton one that just gives codes. Very useful. Oil Temp? Just have the 2 guage cluster, water and fuel, and don't have oil temp. The only wisdom I can offer is my car bucked, hesitated and stalled because I'd not tightened the throttle body bolts when I replaced the throttle body(vacuum leak). Try checking for vacuum leaks.
This car's given me few problems. It's got 148000 miles, I drive in the worst LA traffic, and have yet to replace the expected stuff like waterpump, clutch and shocks.

I hope your high oil temp doesn't indicate an unlikely internal engine problem.
Good luck and keep me posted.
 
Are you still having the same problem.....shuttering at low speed acceleration??? You said you had a code p0012 and a p0340, is this correct? What are your current codes? You also mention your altornator is failing, have you had it tested? What makes u think it's failing? Did you notice the problem after you changed your oil.....did you use a 5w20 synthetic or synthetic blend and have you checked to make sure it's full? When you say 68% rich, is that both banks or just one? 68% is not bad...my car is usually running around that too. If you can answer all or most of these questions I should be able to point you in the right direction. It sounds like your cam phaser/phasers are fully retarted. There are multiple ways for this to occure hence all the questions. I'm guessing you have a stuck open cam phaser solenoid on bank 1!
Is it required to change your oil prior to or after replacing the VCT solenoids? and if so, what type of oil is best?