P0340 help
11-07-2016, 08:32 AM
#1
P0340 help
Getting this code, I've replaced my cam position sensor and it made no difference... my truck runs fine, starts fine, doesn't stall or anything, get a dead miss at idle thought and I'm thinking this is related. After reading up about this code, I read that it could be caused by the truck being out of time, and I'm thinking that maybe this might be my issue because I just had my worn out timing chain and tensioners changed out. Is there a way for me to check time on this? is it checked just like any other engine without VCT? If so, what should it be at idle? Thanks in advance...
11-07-2016, 08:36 AM
#2
Mark
iTrader: (1)
what motor we talking about 5.4 3V ?? you have 2 sensors.
11-07-2016, 11:12 PM
#4
Member
These codes can be caused by several things. Check the wiring to the sensor and check for chaffing or damage.
Another cause can be a bad alternator. Sometimes when the brushes go bad in the alternator, it causes a noisy signal to the sensor(s) and causes a code, though usually both sensors code when that happens.
A bad VCT solenoid can cause this as well. If the solenoid is sticking, it may not allow the phaser to return to full advance at idle and cause the missing you describe.
If the coils and plugs are good, I would suspect the VCT solenoids. I would change those out as they are an inexpensive start and see what happens from there.
Depending on what year you have will determine how easy it is to replace the solenoids. If you have a 2004-2006, then you can remove the VCT solenoid through the valve cover opening. If you have a 2007+, then you will have to remove the valve covers to get the solenoids out because they narrowed the openings in the valve covers to the point to where you can't get them out without the valve cover being removed (those bastard engineers at Ford Motor Company).
Another cause can be a bad alternator. Sometimes when the brushes go bad in the alternator, it causes a noisy signal to the sensor(s) and causes a code, though usually both sensors code when that happens.
A bad VCT solenoid can cause this as well. If the solenoid is sticking, it may not allow the phaser to return to full advance at idle and cause the missing you describe.
If the coils and plugs are good, I would suspect the VCT solenoids. I would change those out as they are an inexpensive start and see what happens from there.
Depending on what year you have will determine how easy it is to replace the solenoids. If you have a 2004-2006, then you can remove the VCT solenoid through the valve cover opening. If you have a 2007+, then you will have to remove the valve covers to get the solenoids out because they narrowed the openings in the valve covers to the point to where you can't get them out without the valve cover being removed (those bastard engineers at Ford Motor Company).
Last edited by 07F150Lariat5.4; 11-07-2016 at 11:17 PM.
11-08-2016, 10:56 AM
#5
These codes can be caused by several things. Check the wiring to the sensor and check for chaffing or damage.
Another cause can be a bad alternator. Sometimes when the brushes go bad in the alternator, it causes a noisy signal to the sensor(s) and causes a code, though usually both sensors code when that happens.
A bad VCT solenoid can cause this as well. If the solenoid is sticking, it may not allow the phaser to return to full advance at idle and cause the missing you describe.
If the coils and plugs are good, I would suspect the VCT solenoids. I would change those out as they are an inexpensive start and see what happens from there.
Depending on what year you have will determine how easy it is to replace the solenoids. If you have a 2004-2006, then you can remove the VCT solenoid through the valve cover opening. If you have a 2007+, then you will have to remove the valve covers to get the solenoids out because they narrowed the openings in the valve covers to the point to where you can't get them out without the valve cover being removed (those bastard engineers at Ford Motor Company).
Another cause can be a bad alternator. Sometimes when the brushes go bad in the alternator, it causes a noisy signal to the sensor(s) and causes a code, though usually both sensors code when that happens.
A bad VCT solenoid can cause this as well. If the solenoid is sticking, it may not allow the phaser to return to full advance at idle and cause the missing you describe.
If the coils and plugs are good, I would suspect the VCT solenoids. I would change those out as they are an inexpensive start and see what happens from there.
Depending on what year you have will determine how easy it is to replace the solenoids. If you have a 2004-2006, then you can remove the VCT solenoid through the valve cover opening. If you have a 2007+, then you will have to remove the valve covers to get the solenoids out because they narrowed the openings in the valve covers to the point to where you can't get them out without the valve cover being removed (those bastard engineers at Ford Motor Company).
11-08-2016, 01:36 PM
#6
Member
If the alternator is ruled as not the cause of the issue; the other possibilities are clogged oil channels in the head, the timing chain is either stretched or has jumped a tooth (or both), or you have an oil pressure problem. Hopefully it is just an alternator.
11-08-2016, 05:37 PM
#7
my bet is low oil pressure or off timing... the guy that did my timing set said one of the guides crumbled when he took it off, he said none of it fell in the oil pan, but a small piece could have... I had him change the oil pump to a high volume Ford racing pump. the chain was slapping before it was changed, so it could have jumped time...
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11-08-2016, 06:21 PM
#8
Member
Yes, whenever a guide is missing pieces, the oil pan should be removed and cleaned and the sump cleaned. That could very well cause an oil pressure problem and cause problems with the phaser timing as well.
Might want to look into having the oil pressure tested before tearing back into it. If the pressure is around 25 PSI at hot idle, then a piece blocking the sump is probably not the case and in fact a chain that has most likely jumped time. Does it only seem to miss when it is hot, or does it miss cold/hot regardless?
Might want to look into having the oil pressure tested before tearing back into it. If the pressure is around 25 PSI at hot idle, then a piece blocking the sump is probably not the case and in fact a chain that has most likely jumped time. Does it only seem to miss when it is hot, or does it miss cold/hot regardless?
11-09-2016, 02:39 PM
#10
Member
Well, that is a plus! I'd go ahead and test the oil pressure and see what it is at hot idle to see if it is in spec. If it checks good, then it is most likely off a tooth on the passenger side chain. These trucks can run somewhat fair even when a tooth off.
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