MAF problems
#1
MAF problems
Ok enlightened ones... Anyone have any idea why I’m having MAF failures every twelve to fourteen months. I have just installed my fourth one in nearly five years. It doesn’t matter if they are cheap Chinese ones or expensive OEM parts, they still fail...
Apart from carrying a spare, I’m at a lost as to cause. Wiring loom all looks ok, no shorts or possible troublesome connections. The vehicle only spits out the P0174 and P0171 codes and the ubiquitous restricted performance. The engine will cough and splutter, shudder and shake and eventually stall (even when kept well under the 3000 RPM restricted performance limit). Most surprisingly, I can stall the engine just by applying a gentle pressure to the top of the MAF. The replacement, once installed has no reaction to even quite robust pressure.
The connector is ok, it’s been cleaned, checked and there’s nothing obvious there either. I’ve taken a failed MAF unit apart with no obviously faults. Even I can not be unlucky enough to have bought so many dodgy ones...
Donna :-)
Apart from carrying a spare, I’m at a lost as to cause. Wiring loom all looks ok, no shorts or possible troublesome connections. The vehicle only spits out the P0174 and P0171 codes and the ubiquitous restricted performance. The engine will cough and splutter, shudder and shake and eventually stall (even when kept well under the 3000 RPM restricted performance limit). Most surprisingly, I can stall the engine just by applying a gentle pressure to the top of the MAF. The replacement, once installed has no reaction to even quite robust pressure.
The connector is ok, it’s been cleaned, checked and there’s nothing obvious there either. I’ve taken a failed MAF unit apart with no obviously faults. Even I can not be unlucky enough to have bought so many dodgy ones...
Donna :-)
#2
Hi Donna,
This is certainly an odd one.
Do all the replacements look the same? I'm wondering if they all come from the same potentially defective source, whether in a very expensive Jaguar box or a cheap Chinese one.
The reaction when you push on the top? Now that's REALLY strange. Any chance you're also flexing the inlet duct or air cleaner housing, which opens a crack and lets in excess unmetered air? That doesn't make sense either, as you say it doesn't happen with the new sensor. But does it happen consistently to the new sensor once it ages a few months and starts to act up? Cue the Twilight Zone music...
This is certainly an odd one.
Do all the replacements look the same? I'm wondering if they all come from the same potentially defective source, whether in a very expensive Jaguar box or a cheap Chinese one.
The reaction when you push on the top? Now that's REALLY strange. Any chance you're also flexing the inlet duct or air cleaner housing, which opens a crack and lets in excess unmetered air? That doesn't make sense either, as you say it doesn't happen with the new sensor. But does it happen consistently to the new sensor once it ages a few months and starts to act up? Cue the Twilight Zone music...
#4
#5
Hi Donna,
This is certainly an odd one.
Do all the replacements look the same? I'm wondering if they all come from the same potentially defective source, whether in a very expensive Jaguar box or a cheap Chinese one.
The reaction when you push on the top? Now that's REALLY strange. Any chance you're also flexing the inlet duct or air cleaner housing, which opens a crack and lets in excess unmetered air? That doesn't make sense either, as you say it doesn't happen with the new sensor. But does it happen consistently to the new sensor once it ages a few months and starts to act up? Cue the Twilight Zone music...
This is certainly an odd one.
Do all the replacements look the same? I'm wondering if they all come from the same potentially defective source, whether in a very expensive Jaguar box or a cheap Chinese one.
The reaction when you push on the top? Now that's REALLY strange. Any chance you're also flexing the inlet duct or air cleaner housing, which opens a crack and lets in excess unmetered air? That doesn't make sense either, as you say it doesn't happen with the new sensor. But does it happen consistently to the new sensor once it ages a few months and starts to act up? Cue the Twilight Zone music...
#6
#7
The generic part number is 22680AA310, but, as JagV8 says don't assume and throw parts at your car. Lean codes can have any number of causes. I'm still looking into what is causing my problems, the MAF failure I believe is only symptomatic of a greater concern.
There are lots of threads here on the more common causes of P0171 and P0174 codes such as vaccuum / air leaks, fuel pressure / fuel feed faults, failing lambda sensors... Get yourself a good realtime monitor and enjoy the challange of finding what's really the problem.
Donna
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#8
The generic part number is 22680AA310, but, as JagV8 says don't assume and throw parts at your car. Lean codes can have any number of causes. I'm still looking into what is causing my problems, the MAF failure I believe is only symptomatic of a greater concern.
There are lots of threads here on the more common causes of P0171 and P0174 codes such as vaccuum / air leaks, fuel pressure / fuel feed faults, failing lambda sensors... Get yourself a good realtime monitor and enjoy the challange of finding what's really the problem.
Donna
There are lots of threads here on the more common causes of P0171 and P0174 codes such as vaccuum / air leaks, fuel pressure / fuel feed faults, failing lambda sensors... Get yourself a good realtime monitor and enjoy the challange of finding what's really the problem.
Donna
Donna, thanks for the part number....fyi...I have been member of this forum for a few years and I have a good real time monitor and I have been chasing these codes for years. I have been the recipient of a wealth of knowledge from others here about the lean codes and the MULTITUDES of possible reasons..and I have engaged in throwing parts at it for at least 3 years. This is not my first Jag. I have owned an older XJS 6 cylinder, a gorgeous early '90's red convertible v 12, a debut year 2002 x type, and this s type purchased new in 2005. The 2 older cars were awesome, despite the notoriously bad Jaguar reputation back then and the only complaint I had about the V12 convertible was an oil leak. The x type never gave me one day of trouble. I traded it in to buy the s type, and for the past 3 or 4 years, this car has driven fine, but the lean codes have been a maddening experience. If it werent for need for smog, I would just drive it as is, but since I can't I am forced into battle with this freaking computer. Venting.
#9
#10
Things I have not done.....all the 02 sensors, the lower intake gaskets, the fuel tank seals, the fuel pump itself.
#11
If you let the LTFTs learn - i.e. do NOT clear codes and do NOT disconnect the battery - after a number of drives, what are they? There really are a lot of posts about this! If they drop significantly when revved you know you have a leak.
If you can't find the leak it sounds cheaper to find a tech who can than go on swapping parts at big cost.
If you can't find the leak it sounds cheaper to find a tech who can than go on swapping parts at big cost.
#12
If you let the LTFTs learn - i.e. do NOT clear codes and do NOT disconnect the battery - after a number of drives, what are they? There really are a lot of posts about this! If they drop significantly when revved you know you have a leak.
If you can't find the leak it sounds cheaper to find a tech who can than go on swapping parts at big cost.
If you can't find the leak it sounds cheaper to find a tech who can than go on swapping parts at big cost.
#13
I really wish you'd read existing posts. They do not ask about highway speed but to rev when parked with a hot engine.
If the LTFTs drop a lot then you have a leak. If one tech could not find it then about all you can do is find another or DIY but swapping parts looks costly and unlikely to fix it. I suppose if you can "game" the system and pass smog that may be what you want.
You could try looking at sensor readings but unless you understand what they do and how they should behave this needs a (competent) tech.
If the LTFTs drop a lot then you have a leak. If one tech could not find it then about all you can do is find another or DIY but swapping parts looks costly and unlikely to fix it. I suppose if you can "game" the system and pass smog that may be what you want.
You could try looking at sensor readings but unless you understand what they do and how they should behave this needs a (competent) tech.
Last edited by JagV8; 02-02-2018 at 02:28 PM.
#14
I really wish you'd read existing posts. They do not ask about highway speed but to rev when parked with a hot engine.
If the LTFTs drop a lot then you have a leak. If one tech could not find it then about all you can do is find another or DIY but swapping parts looks costly and unlikely to fix it. I suppose if you can "game" the system and pass smog that may be what you want.
You could try looking at sensor readings but unless you understand what they do and how they should behave this needs a (competent) tech.
If the LTFTs drop a lot then you have a leak. If one tech could not find it then about all you can do is find another or DIY but swapping parts looks costly and unlikely to fix it. I suppose if you can "game" the system and pass smog that may be what you want.
You could try looking at sensor readings but unless you understand what they do and how they should behave this needs a (competent) tech.
Donna, if you are still following, can you please tell me what specific codes or readings you were getting that led to your conclusion of faulty mafs?
#15
#16
Joycesjag....I was merely replying to inquiries about my symptoms after I asked Donna a question about her maf diagnosis. And I still have question about that diagnosis on her mafs, nor have I seen much other in the way of responses to her original question. You're getting a little uppity. I thought the forum was about helping each other out. If not the case, I'll stay off the site and figure it out myself.
#17
Joycesjag....I was merely replying to inquiries about my symptoms after I asked Donna a question about her maf diagnosis. And I still have question about that diagnosis on her mafs, nor have I seen much other in the way of responses to her original question. You're getting a little uppity. I thought the forum was about helping each other out. If not the case, I'll stay off the site and figure it out myself.
Unlike yours truly, JoycesJag is a man of few words. When he says something, I listen. He has a wealth of knowledge about these cars. Through the medium of this forum, it's easy to miss the cues as he gently tries to persuade you back to your other thread, so as not to steer this one (about Donna and her MAF sensor punch card) into the weeds. I've got to admit it gets frustrating sometimes to offer some in-depth technical advice and it never really gets any follow through. I'm not picking on you, as this applies to many folks seeking advice in this forum.
I'm sure no offense was intended in this latest dust up. Now I've always suspected JoycesJag could best me in a barroom brawl, so I've always been careful to stay on this good side. However, I do know he's presently recovering from knee surgery, so I'm sure if we followed prison rules and I went all Tonya Harding on him, I could best him. And if nothing else, I'm sure I could outrun him and his gimpy knee.
Now I just posted some stuff in the other thread, so take a look and reply there as we try to help you.
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joycesjag (02-04-2018)
#18
Now, now, don't make me break out the tranquilizer gun.
Unlike yours truly, JoycesJag is a man of few words. When he says something, I listen. He has a wealth of knowledge about these cars. Through the medium of this forum, it's easy to miss the cues as he gently tries to persuade you back to your other thread, so as not to steer this one (about Donna and her MAF sensor punch card) into the weeds. I've got to admit it gets frustrating sometimes to offer some in-depth technical advice and it never really gets any follow through. I'm not picking on you, as this applies to many folks seeking advice in this forum.
I'm sure no offense was intended in this latest dust up. Now I've always suspected JoycesJag could best me in a barroom brawl, so I've always been careful to stay on this good side. However, I do know he's presently recovering from knee surgery, so I'm sure if we followed prison rules and I went all Tonya Harding on him, I could best him. And if nothing else, I'm sure I could outrun him and his gimpy knee.
Now I just posted some stuff in the other thread, so take a look and reply there as we try to help you.
Unlike yours truly, JoycesJag is a man of few words. When he says something, I listen. He has a wealth of knowledge about these cars. Through the medium of this forum, it's easy to miss the cues as he gently tries to persuade you back to your other thread, so as not to steer this one (about Donna and her MAF sensor punch card) into the weeds. I've got to admit it gets frustrating sometimes to offer some in-depth technical advice and it never really gets any follow through. I'm not picking on you, as this applies to many folks seeking advice in this forum.
I'm sure no offense was intended in this latest dust up. Now I've always suspected JoycesJag could best me in a barroom brawl, so I've always been careful to stay on this good side. However, I do know he's presently recovering from knee surgery, so I'm sure if we followed prison rules and I went all Tonya Harding on him, I could best him. And if nothing else, I'm sure I could outrun him and his gimpy knee.
Now I just posted some stuff in the other thread, so take a look and reply there as we try to help you.
My frustration here is that while I agree that my diagnostics point to a vacuum leak, I have determined that from what I see on this car, the codes are not coming fro a vacuum leak under the hood. And the forum is rife with threads about 0171 and 0174 being attributed to a plethora of possible causes, including maf...and since Donna started this thread about maf, I picked up on it and asked in essence..."what led her to determine her codes were coming from maf" .
You have made a good effort at intervention here , and I know it is to continue to help me. You should try your hand at negotiation between CNN and Fox news.
I will reply to your post on my other thread...then start a fresh one with further questions. thankyou.
#19
Hiya,
It wasn't codes that lead me to the MAF as the problem but rather a far more unusual occurence. As I said earlier in this thread, I merely opened the hood and leaned in, supporting myself on the airfilter box and on the hose in the vicinity of the MAF and the car stalled.
I restarted the engine and began trying to repeat the stall by placing pressure on the individual air intake parts. A gentle pressure on the MAF top plate stalled the car. This was repeatable. MAF was inspected, cleaned, mounting point checked, connector cleaned and inspected and then reinstalled a few times. Problem persisted. MAF was swapped out for a new unit and the problem disappeared.
The only codes in the system were the P0171 and P0174 which, as you are aware are not particularly insightful as to cause or diagnosis.
Now I'm unconvinced that I have just been unlucky with MAF units. I am currently trying to see what could be causing the MAF failures, thinking that it's probably electrical but I cannot discount something physical within the air intake system.
If I find a cause, I'll certainly post the solution.
I do hope this helps...
Last edited by Donna; 02-04-2018 at 05:05 PM.
#20
Hmmm strange to see MAF's to behave in this manor. Cant say I've seen this before.
So to make a long story short - you get check engine light, P0171 & P0174 codes logged. Since you were applying pressure of some sort to the top of the MAF, led you to believe it was at fault, being that you replaced, and fault went away.
Now it's returned..... As for electrical issues, I have seen issues with the engine harness in the past on V6 and V8, early and late model. These 2 codes being logged could be a multitude of things causing it.
May need to take it to a dealer or someone who has SDD and see if any flight data has been logged along with those 2 codes. If you can get this info it will definitely help.
As for jakesdad - the slightest vacuum leak can wreak havoc. Even if you've had the intake off for injectors, did you replace the gaskets or reuse old ones? There are several vacuum hoses on the V6, some are covered in wire conduit, so you may need to disassemble to fully inspect to eliminate as cause. The upper and lower intake gaskets, these can be cut while refitting intake, doesn't take much. IMT valve O-rings fail just like the X-Type ones did, another place to look.
As I mentioned to Donna, you may need to take to dealer or someone with SDD, or has a proper scanner than can monitor sensor data, or even read flight data, this will give insight as to what the car was doing when the fault occurred. I would suggest this before throwing parts at the issue, it can..... no it " will " be expensive, and time consuming.
Keep in mind, if you've been looking at one problem for so long, you start to get frustrated. May need to go back to square 1 and start over, you " may " have missed something. I've done this when I've been stumped, just a suggestion.
So to make a long story short - you get check engine light, P0171 & P0174 codes logged. Since you were applying pressure of some sort to the top of the MAF, led you to believe it was at fault, being that you replaced, and fault went away.
Now it's returned..... As for electrical issues, I have seen issues with the engine harness in the past on V6 and V8, early and late model. These 2 codes being logged could be a multitude of things causing it.
May need to take it to a dealer or someone who has SDD and see if any flight data has been logged along with those 2 codes. If you can get this info it will definitely help.
As for jakesdad - the slightest vacuum leak can wreak havoc. Even if you've had the intake off for injectors, did you replace the gaskets or reuse old ones? There are several vacuum hoses on the V6, some are covered in wire conduit, so you may need to disassemble to fully inspect to eliminate as cause. The upper and lower intake gaskets, these can be cut while refitting intake, doesn't take much. IMT valve O-rings fail just like the X-Type ones did, another place to look.
As I mentioned to Donna, you may need to take to dealer or someone with SDD, or has a proper scanner than can monitor sensor data, or even read flight data, this will give insight as to what the car was doing when the fault occurred. I would suggest this before throwing parts at the issue, it can..... no it " will " be expensive, and time consuming.
Keep in mind, if you've been looking at one problem for so long, you start to get frustrated. May need to go back to square 1 and start over, you " may " have missed something. I've done this when I've been stumped, just a suggestion.