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A Mechanic's Life - Tales From Under the Hood

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Comments

  • thecardoc3thecardoc3 Member Posts: 5,741
    http://www.reuters.com/article/us-tesla-warranty-idUSKCN0XO1M3

    Not all that surprising, and this is with everything "in house".
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I wonder how much of this is dependent on how willing the automaker is to honor warranty claims. I mean, if you put your customers on the torture rack every time they submit a warranty claim, you're absolutely going to have lower warranty costs (and ultimately fewer customers, but that's another problem).

  • thecardoc3thecardoc3 Member Posts: 5,741
    edited April 2016
    If you think it's complicated now, just wait as we get closer to 54.5mpg CAFE requirement in 2025.

    This author is raising some of the right points. http://www.autonews.com/article/20160419/BLOG06/160419880/-1

    More complex engines and transmissions will also require continual training of the technicians tasked with repairing and maintaining new light vehicles. The industry is already short some 150,000 technicians by some estimates. Would you pursue a career knowing that not only would you have to work long hours in a physically tough environment, but that you will also be taking classes for your entire working career?

    That's on top of all of the other reasons to do something else with your life....
  • steverstever Guest Posts: 52,454
    edited April 2016
    lol, even "lowly" cashiers have recently had to take classes to learn how to process the new chipped credit cards. Can you think of any field where the tools of the trade aren't constantly changing?

    (And don't try to tell me that standing on your feet for an 8 hour shift at Wal-Mart dealing with the public while bagging groceries isn't a physically tough environment).
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Doc has a point though. Often garage environments are too hot, or too cold. Plus you run the risk of physical injury every day you're there.

    Picture a "lowly" cashier having to work next to an open door in winter, or a picture window in summer, with broken glass mixed in with the coins in her register, and having to diagnose what's inside each shopping cart.
  • steverstever Guest Posts: 52,454
    Here's one Doc will love. Lazy mechanics just want to ride around all day in someone else's car. :)
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Gotta admit, those guys are dedicated!
  • thecardoc3thecardoc3 Member Posts: 5,741
    I'd been following that, there wasn't much to try and offer up to this point. Funny, maybe sad actually, problems like that aren't problems for techs that have the right skills, training and equipment. But between not getting paid correctly, and little to no respect from the public at large anyway situations like that one end up right where they deserve to, and that's without someone who could have fixed it "easier". FWIW, I would have had no trouble proving exactly what was wrong by doing what I normally do and by simply being patient and waiting for it to act up. Then with real proof of the failure and a proper repair in hand, the extended road test that they are doing now which is trying to prove a negative wouldn't be necessary. When they fall into the situations where they don't know if it really is repaired as this one has there are no winners, only survivors. The lessons learned from them do more to teach people to avoid them than they do to step up and take on the challenges they present.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    edited April 2016
    I don't believe every problem is solvable however---I mean, economically solvable by a technician. Sure, you can take the whole car apart I guess if someone is willing to pay you 200 hours of labor. Or you could drag it back to the factory and have teams of engineers work on it.

    But there's not a technician alive that hasn't been gunned down in the dirt by a car.
  • thecardoc3thecardoc3 Member Posts: 5,741
    Going from the perspective that you are still trying to suggest that a car has to be torn completely apart in order to try to solve the really difficult problems, it proves just how little is known about what it really does take to do this work. It doesn't take a team of engineers, and it sure doesn't take hundreds of hours. It does take experience, training, and a patient, disciplined approach and above all it has to be rewarded and that is what is missing. As far as getting beat by something consider one of the recent responses that would have seen you get beat by a turn signal and headlight that wasn't working right, so what's your point? If someone has to try and fail, shouldn't they get more respect for attacking the most difficult issues to the best of their abilities as opposed to not even recognizing a classic ground fault description?

    This is all pretty typical though. As someone is learning to be a technician, they get to enjoy being belittled over every new lesson the job will teach them. Work hard, study more and genuinely rise to the top in the trade and your rewards will be comments that serve no purpose other than to tell you that you still aren't good enough.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I beg to differ. Sometimes the most difficult problems do require serious disassembly, and when it comes to modern cars with electrical "ghosts" deep within wiring harnesses that are multiplexed, an engineer might be required. Why do you think cars are bought-back by companies? What about the Toyota UA debacle?

  • steverstever Guest Posts: 52,454
    How many hours of diagnostic testing are we talking about? For a "hard" problem I mean.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    You mean a real devil of a problem? I could see 50 hours. I have witnessed 100 hours on an exotic car. I know of a Porsche repair right now (car running incredibly rich) that's well over 50 hours--it's probably going to end up being an internal engine problem of some freakish nature.
  • steverstever Guest Posts: 52,454
    Let's use a middle America labor rate, say $100 an hour instead of your $150. So we're at $5,000 and we still don't know the problem.

    Better flat rate it. ;)
  • thecardoc3thecardoc3 Member Posts: 5,741

    I beg to differ. Sometimes the most difficult problems do require serious disassembly,

    No they don't. The moment you start taking things apart, you change the parameters of the situation and then you might never find the answer. The problem might go away, but its no different than the Toyota Highlander thread. Now they are stuck trying to prove a negative and hoping that if they drive it one hundred miles and it doesn't act up that it might be repaired. Without proof of what was really wrong, there is doubt that it has actually been repaired.



    and when it comes to modern cars with electrical "ghosts" deep within wiring harnesses that are multiplexed, an engineer might be required.

    What's the difference between an engineer and a technician? Education? Experience? Tenacity? Top technicians have educations that are easily on par with most engineers. They just don't all have a piece of paper that says so.

    Multiplexing isn't a big deal. You can google and get a million (billions of ?) examples of multiplexed circuits. I present a four hour class and have people who have never studied electronics before that evening walking out the door not only knowing how one works, they know practical routines that allow them to test and solve problems with multiplexed circuits.


    Why do you think cars are bought-back by companies? What about the Toyota UA debacle?

    Heck that's the easiest question you have ever asked. Because its cheaper and easier to buy back a car once in a while than it is to train and support a trade full of fully qualified technicians.

  • thecardoc3thecardoc3 Member Posts: 5,741
    stever said:

    How many hours of diagnostic testing are we talking about? For a "hard" problem I mean.

    Define hard. Hard for you? Hard for a DIY'er? Hard for most shops/techs? Hard due to technical complexity or just because a failure is random in nature?

    There isn't a single practical answer to your question and that's why people who have never spent any time in a shop and tried to learn how to be a technician don't have a clue as to what it really takes to do the job. I've had cars that beat a number of people up over an extended period of time that took less than five minutes to figure out. Some of those were little more than dumb luck where a random intermittent just happened to be occurring at the very moment I started looking at the car. Others came down to insufficient tooling or training where the problem simply outclassed their abilities. Most of the time, what others think is hard takes less than an hour to solve and that goes for just about any active failure. About the only time that it takes longer than that are when there needs to be some disassembly for component access to perform pinpoint testing.

    I've had cars presented with multiple failures that the owner kept driving and driving as more things went wrong until they finally had no choice but to do something about it. Others where previous attempts elsewhere to fix something only succeeded in adding additional problems on top of the original failure.

    I've had cars that took more than a month just to get some random failure to occur and had less than five seconds to solve before the failure stopped occurring. Some of those were solved in that five seconds, others took more than one occurrence to solve. That's where having a good game plan and setting the testing in advance makes all the difference. BTW, that's something that I have given you some examples of in previous posts. There were some of those never got to be diagnosed. It's not that they couldn't be figured out, lots of owners just don't have the time, nor the patience to allow it to be done.

    I've had customers that once a baseline investigation of a problem was started, gave them back their car so that they could drive it around until the random failure occurred. When it happened, if they could drive it to the shop while the problem was occurring, I would drop what I was otherwise doing and figure it out. Or, if the car wasn't drivable when the problem occurred when I would go to them and analyze the issue wherever the car and customer were at.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Unless you have X-Ray vision, you most certainly have to occasionally take something apart--how do you analyze wiring harnesses without pulling the instrument panel? Or identify the source of differential noise or transmission debris without disassembly?
  • thecardoc3thecardoc3 Member Posts: 5,741

    Unless you have X-Ray vision, you most certainly have to occasionally take something apart

    The operative word there is occasionally.


    --how do you analyze wiring harnesses without pulling the instrument panel?

    Did you forget the Taurus transmission shift solenoid control circuit post already?


    Or identify the source of differential noise or transmission debris without disassembly?

    First of all we don't always know exactly what we are hearing without disassembly especially when its a sound or system that we have never encountered before but that stops being diagnostics and falls under repair at that point. But at least we actually listen to the noise while driving the car, attach listening devices such as chassis ear, operate the vehicle in different gears and loads etc. How do you or anyone else tell someone what is wrong without doing any of that?
  • thecardoc3thecardoc3 Member Posts: 5,741
    After previous repair attempts by the vehicle owner and another shop (who at least got it to run so they made some progress) a 2005 Cobalt presents with the following codes.
    Radio B1001, U2100,U2103, B1325
    Power Steering Control Module C0845-01, C0000-71, U2105,U2107
    ECM U0101,
    BCM U2106, U2111
    SRS B1370

    Which codes are the most important and are the ones that indicate where the diagnostics should start?

    FWIW, it took just under twenty minutes to solve.......
  • steverstever Guest Posts: 52,454
    Kind of sounds like a flat rate diagnostic fee might smooth the bumps for customers who typically have a "15 minute" problem but rarely would have an hour (or two) diagnostic problem.
  • roadburnerroadburner Member Posts: 17,312



    Which codes are the most important and are the ones that indicate where the diagnostics should start?


    A 2005 Cobalt? I suspect the solution lies somewhere between the numbers for trade-in and salvage value....

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • thecardoc3thecardoc3 Member Posts: 5,741
    The question was, "Which codes are the most important and are the ones that indicate where the diagnostics should start? " Anything beyond that isn't important.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    I think I'd attack the BCM. I don't think 2106 is important.
  • steverstever Guest Posts: 52,454
    edited April 2016
    Check the grounds and connections (i.e., pull the plugs to the modules and plug 'em back in)?
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Also check the fuses!
  • thecardoc3thecardoc3 Member Posts: 5,741

    I think I'd attack the BCM. I don't think 2106 is important.

    Actually it is one of the codes that are important.

  • thecardoc3thecardoc3 Member Posts: 5,741


    A 2005 Cobalt? I suspect the solution lies somewhere between the numbers for trade-in and salvage value....

    Hey, while you're here. You'd love the 1995 Jaguar XJR that's here setting codes P0411, P0420, and P0430. Anyone putting anti-foulers on the downstream O2 sensors not only would not have fixed it they would have added a problem on top of the real failure.
  • roadburnerroadburner Member Posts: 17,312
    Secondary air flow? Easy- flash the ECU so that the fault is stored but doesn't illuminate the SES light. That's what most everyone with an E39 M5 does.

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • thecardoc3thecardoc3 Member Posts: 5,741
    That won't work in areas that have emissions testing.
  • thecardoc3thecardoc3 Member Posts: 5,741
    The important codes for the Cobalt are the communication codes, which are all of the U-codes. Before you check fuses, what you need is a schematic and a scan tool so that you can identify what modules are not communicating right now if any. The TCM was the only module not communicating. The PCM and TCM share the same power feeds so it can't be a fuse but it could be a problem where the power isn't making it all of the way to the TCM. The first tests confirmed powers and ground connections for the TCM. The next check is communication. Here is pin 31 to ground.
    Next?
  • roadburnerroadburner Member Posts: 17,312

    That won't work in areas that have emissions testing.

    Really? :p No emission testing in my neck of the woods. That said, there is another more involved method that actually spoofs the secondary air flow so no fault code is set. I'm glad I don't have to deal with that.

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • thecardoc3thecardoc3 Member Posts: 5,741
    Its funny watching someone work so hard to avoid fixing an exhaust leak.
  • roadburnerroadburner Member Posts: 17,312

    Its funny watching someone work so hard to avoid fixing an exhaust leak.

    It's actually more amusing to see you make a smug and condescending comment that is 100% incorrect:
    S62 Secondary Air System Repair

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • steverstever Guest Posts: 52,454
    edited April 2016
    What a rat's nest and what a dumb way to wire something exposed to the elements and rough terrain. Not to mention real rat attraction.
  • thecardoc3thecardoc3 Member Posts: 5,741

    Its funny watching someone work so hard to avoid fixing an exhaust leak.

    It's actually more amusing to see you make a smug and condescending comment that is 100% incorrect:
    S62 Secondary Air System Repair
    When it comes to condescending comments, it seems you could teach me a lot. I'm talking about the Jaguar and you are talking about a different vehicle.

    Anyway, you want to talk about BMW's problems? Go right ahead. Carbon deposits are problems that aren't limited to any one engine or manufacturer and they darn sure aren't new.
  • thecardoc3thecardoc3 Member Posts: 5,741
    stever said:

    What a rat's nest and what a dumb way to wire something exposed to the elements and rough terrain. Not to mention real rat attraction.

    Are you referring to the Cobalt? There are some cars that have modules exposed to more elements than it does. One of the poorest choices to locate a control module is under the carpeting, under the seats.

    Compare the previous photo to this one. Why is there a difference with the module disconnected? What does that voltage actually mean?


  • roadburnerroadburner Member Posts: 17,312
    edited May 2016
    I sure didn't realize that the carbon problem was so ubiquitous...
     

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    edited May 2016
    Porsche, Audi and BMW have been putting modules in stupid places for decades. Under seats? Next to cupholders?--what could possibly go wrong?
  • thecardoc3thecardoc3 Member Posts: 5,741

    I sure didn't realize that the carbon problem was so ubiquitous...
     

    You know the problem with forums like this is that it isn't possible to read that and decide if its yet another condescending remark from you or not.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    edited May 2016
    carbonized intake valves on certain VW/Audi engines (2.0T, V-6) is a well-known problem but generally not much of a problem on other direct injection engines. Some low mileage Ford Ecoboost engines have this issue however.
  • thecardoc3thecardoc3 Member Posts: 5,741
    Especially with the introduction of GDI. When the fuel injectors were in the intake ports fuel additives would do a decent job of preventing accumulation of deposits. Now that the injectors are in the cylinder, there is nothing to prevent growth on the valves.

    You should get a chance to use the walnut shell blaster sometime and see just how nasty that build up gets to be.
  • thecardoc3thecardoc3 Member Posts: 5,741
    BTW, here is one more photo from the Cobalt.
    This is CAN Hi with the module disconnected.



    This was over 6v with it connected. The TCM is bad. The voltages shown with the module disconnected are normal for CAN circuit communication. They could be compared if need be to pins 6 and 14 of the ALDL. A scope would tell you a lot more about the circuit than a voltmeter does. With the TCM connected the bias voltages start pushing high. The ground circuit for the TCM was confirmed by loading it with 4 amps of current from a headlight with no notable change in a measurable drop.

    So what happened?

    The previous shop had to tow the car in after the boyfriend was trying to work on it. They found the under hood fuse block corroded and failed and replaced it with a new dealer part. Upon getting the car started they had power steering system warnings on the instrument cluster, a service engine soon MIL, the transmission stuck in second gear no communication with the TCM and various other issues.

    The customer claims that none of those problems existed previously, however that was before the boyfriend was doing something (undisclosed) to the car where it ended up in a no-start and occasional start with immediate stall condition. Many of the codes listed were historical faults. Some of them were the result of insufficient system voltage, which was very likely caused by the failing fuse block assembly.

  • roadburnerroadburner Member Posts: 17,312
    edited May 2016
    carbonized intake valves on certain VW/Audi engines (2.0T, V-6) is a well-known problem but generally not much of a problem on other direct injection engines. Some low mileage Ford Ecoboost engines have this issue however.
    The carbon issue that I was alluding to with the BMW S62 has nothing to do with the GDI intake valve deposit issue; the S62 has secondary air passages built into the cylinder heads. You have to pull the heads to clear the carbon from the passages- which is why other methods are used to fix the "insufficient secondary air flow" SES. 
    As for GDI issues, there was a lot of chatter about the problem on the Mazdaspeed forums involving the 2.3 turbo but my 2007 made it to 158k with no degradation in either performance or drivability. 
    I barely have 20k miles on the N55 in my 2 Series, but my SA and others at BMW who should know tell me that intake valve deposits won't be a concern as long as I "give it some stick" on a regular basis. 
    I don't think that will be a problem.  B)

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • qbrozenqbrozen Member Posts: 32,889

    I barely have 20k miles on the N55 in my 2 Series, but my SA and others at BMW who should know tell me that intake valve deposits won't be a concern as long as I "give it some stick" on a regular basis. 
    I don't think that will be a problem.  B)

    Did they indicate why that should be the case?

    The N54 needs the valves blasted with walnut shells every 50k or so, no matter how you drive it.

    '11 GMC Sierra 1500; '08 Charger R/T Daytona; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '08 Maser QP; '11 Mini Cooper S

  • roadburnerroadburner Member Posts: 17,312
    qbrozen said:



    Did they indicate why that should be the case?

    The N54 needs the valves blasted with walnut shells every 50k or so, no matter how you drive it.

    I think it has to do with making sure the intake valves get good and hot, thereby burning off some of the carbon. My SA said that he sees a significant difference between cars that are driven gently and those that get exercised regularly.

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Do you really think driving fast makes internal engine parts that much hotter? I think you're better off just doing the cleaning as part of the BMW maintenance schedule. Kind of a drag, as you have to take the manifold off. The Scion FR-S has a clever way around this carbonization problem.

  • roadburnerroadburner Member Posts: 17,312
    edited May 2016

    Do you really think driving fast makes internal engine parts that much hotter? I think you're better off just doing the cleaning as part of the BMW maintenance schedule. Kind of a drag, as you have to take the manifold off. The Scion FR-S has a clever way around this carbonization problem.

    Well, the longer the intake valve stays off the seat the hotter it will get. The other factor that seems to increase deposits is a driving style involving frequent short trips. In any case I have yet to determine a rationale for my SA to concoct the story that he sees reduced intake deposits on cars that are driven harder; perhaps it's a nefarious plot to deprive his long-time employer of the profits from the walnut blasting service?

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

  • thecardoc3thecardoc3 Member Posts: 5,741
    There is one engine platform that won't have the problems like all of the rest and that is Toyota's D4S which uses both port injectors and direct injectors. Newer designs have managed to reduce the condition, and part of that is the engine oil standards and the variable valve lift strategies.

    There are a lot of articles on the subject and there are a lot of differing theories as to the causes and the ultimate solutions.

    http://www.underhoodservice.com/direct-injection-engines-develop-carbon-deposits/
    http://www.autoguide.com/auto-news/2015/01/is-carbon-buildup-a-problem-with-direct-injection-engines-.html
  • qbrozenqbrozen Member Posts: 32,889


    I think it has to do with making sure the intake valves get good and hot, thereby burning off some of the carbon. My SA said that he sees a significant difference between cars that are driven gently and those that get exercised regularly.

    Hmmm... hot enough to go into limp mode? Cause mine did that all the time, yet I still had to get the walnut blasting done (snuck in under the warranty window, so I didn't pay for it). No offense intended, but I think your SA just made that up.

    '11 GMC Sierra 1500; '08 Charger R/T Daytona; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '08 Maser QP; '11 Mini Cooper S

  • roadburnerroadburner Member Posts: 17,312
    I can't see why he would; he's that rare SA who is also a knowledgeable mechanic, and he has no reason to make things up.

    Mine: 1995 318ti Club Sport; 2020 C43; 2021 Sahara 4xe 1996 Speed Triple Challenge Cup Replica Wife's: 2015 X1 xDrive28i Son's: 2009 328i; 2018 330i xDrive

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