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A Mechanic's Life - Tales From Under the Hood

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Comments

  • steverstever Guest Posts: 52,454
    Even if the cap is the problem in only 1% of the cases, with 300 million cars on the road, that's still pushing two million cars (even after throwing out ~100 million older ones that may not be OBDII cars - like Xwes's lol).
  • xwesxxwesx Member Posts: 16,756
    Hey now, don't make fun of my old beast(s)! :cry:

    -Wes-
    2018 Subaru Crosstrek, 2014 Audi Q7 TDI, 2013 Subaru Forester, 1969 Chevrolet C20, 1969 Ford Econoline 100, 1976 Ford F250
  • steverstever Guest Posts: 52,454
    OBDII came out in 1996. My Subie made the cut with a few months to spare. :D
  • thecardoc3thecardoc3 Member Posts: 5,741
    Replacing the gas cap first failed to fix 100% of the cars that have had an evaporative emissions issue that then had to be taken to a shop to be properly diagnosed and repaired.
  • thecardoc3thecardoc3 Member Posts: 5,741
    OBDII officially came out in 96. Honda drug their feet and got in trouble with some of the vehicle systems. Some manufacturers like GM and Ford actually had the systems on the road as early as 94, they just didn't call it OBDII.

    Evaporative systems didn't need to be fully enhanced fleet wide until 99. The non enhanced systems couldn't test for leaks, and only had to prove that they could/would purge.
  • srs_49srs_49 Member Posts: 1,394
    Replacing the gas cap first failed to fix 100% of the cars that have had an evaporative emissions issue that then had to be taken to a shop to be properly diagnosed and repaired.

    Think about what you just said - "...that then had to be taken to a shop to be properly diagnosed and repaired".

    So what you're describing is a limited subset of the total population of cars that have had evaporative emissions issues - that is, those that were brought into a repair shop.

    If the total number of vehicles that experience an evaporative emissions failure is 100, and replacing the gas cap solves the problem in 90 of those cases, but doesn't in 10, those 10 are the ones you or someone else is going to see in your shop. So from your or some other shop's experience 100% of the cars (that you diagnosed and repaired) needed something other than a gas cap replacement. You (or some other shop) never see the other 90 cars.
  • thecardoc3thecardoc3 Member Posts: 5,741
    Experience has proven that what you linked fails to fix the cars, the majority of the time. It is a lack of knowledge and experince that has you clinging onto your perception that a gas cap being loose or bad is the most common cause for evap issues.

    It's almost funny how you are ignoring what it really says.

    Possible Solutions With a P0442, the most common repair is to:

    •Remove and reinstall the gas cap, clear the codes, and drive for a day and see if the codes come back.
    •Otherwise, replace the gas cap, or
    •Inspect the EVAP system for cuts/holes in tubes/hoses


    By far the "most common" repair is a close tie between the filler neck corroding and leaking, and the vent valve failing to seal for one reason or another so the car simply cannot test itself. Why is it that your link doesn't mention either one of those? That's what you get when someone who really doesn't know anything about how the system works, nor how they fail, and yet they still try to give people advice.

    In many way's it's similar to an instructor, VS a teacher who each are presenting a continuing educational class for auto repair. You can take the greatest teacher in the world, and while he/she may do a great job teaching if they have no idea that the material they are trying to present is flawed, that makes the training, just like your link be worthless. It takes a truly qualifed instructor, who knows how to do the work to recognize when there are flaws in the material and he/she must correct it so that the educational material is worth the techs time to attend.

    Is there a reason why you don't want consumers to understand how the cars really fail, and what it takes to diagnose and repair them, correctly?
  • steverstever Guest Posts: 52,454
    edited December 2012
    I know you don't see many new cars since you don't do warranty work, but I doubt that many 2012 models with the CEL on throwing a P0442 have corroded filler necks.

    Well, up here in the UP, it's a definite possibility. :shades:

    [Edit] This is good timing. Check out this cry for help over in Edmunds Answers. A 2005 Ford Five Hundred throwing P0442. Place your bets. :shades:
  • thecardoc3thecardoc3 Member Posts: 5,741
    Take note of the enabling conditions for the onboard computer to run a P0442 test. Especially note the line I highlighted in BOLD

    Conditions for Running the DTC

    IMPORTANT:

    The following conditions must be met prior to ignition OFF.

    •Before the ECM can report DTC P0442 failed, DTCs P0446, P0455, and P0496 must run and pass.
    •DTCs P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0128, P0443, P0446, P0449, P0452, P0453, P0463, P0503, P1106, P1107, P1111, P1112, P1114, P1115, P1516, P2101, P2108, P2120, P2125, P2129, P2138, P2610 are not set.
    •The diagnostic runs once after a cold start drive cycle.
    •The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
    •The start-up engine coolant temperature (ECT) is less than 30°C (86°F).
    •The start-up IAT and ECT are within 8°C (15°F).
    •The barometric pressure (BARO) is more than 74 kPa.
    •The ambient air temperature is between 2-32°C (36-90°F).
    •The engine run time minimum is 10 minutes.
    •The vehicle has traveled more than 5 kilometers (3 miles) this trip.
    •The ECT is more than 70°C (158°F).
    •The fuel level is between 15-85 percent.
    •The ignition is OFF.
    •A refueling event is not detected.
    •DTC P0442 runs once per drive cycle when the above conditions are met.
    •One test occurs at ignition OFF after a drive cycle, and may require up to 45 minutes to complete. No more than 2 tests per day are allowed.
  • thecardoc3thecardoc3 Member Posts: 5,741
    Think about what you just said - "...that then had to be taken to a shop to be properly diagnosed and repaired".

    I know exactly what I said. You have to speculate to try and find fault with it while you have no facts to support your argument. Meanwhile, you gotta love what can be done with a carefully scripted use of "percentage". :shades:
  • thecardoc3thecardoc3 Member Posts: 5,741
    Edit] This is good timing. Check out this cry for help over in Edmunds Answers. A 2005 Ford Five Hundred throwing P0442. Place your bets.

    I bet a properlly trained and equipped technician taking a disciplined approach to this repair event would prove exactly what the failure is, the first time so long as nobody disturbs the cars present condition.

    The correct approach is to connect the scan tool and command the onboard test to run in the bays and confirm that a leak is present. Then, command the vent valve closed, and the purge vlave open to start pulling a vacuum on the system. Then try to tighten the cap, if you make a difference in the leak, it was loose and you have legitimate proof. If that made no difference, then you clamp the filler neck hose off and see if the leak is still there or not. Then you clamp off the vent valve hose and see if the leak is still there or not. You would continue to isolate different parts of the system until the exact location of the leak is proven and repaired. Then you repeat the onboard test to prove that the problem has been correctly addressed.

    It isn't wrong, to do the job correctly.
  • srs_49srs_49 Member Posts: 1,394
    I know exactly what I said

    But, did you say what you meant :blush: ?

    You really have no idea how many code P0442 problems are solved by a simple gas cap replacement, do you? Of course you can't, because you have no idea how many of those vehicles never made it to your (or any other) shop.

    I'll stick with my 90% number.
  • steverstever Guest Posts: 52,454
    I bet a properlly trained and equipped technician taking a disciplined approach to this repair event would prove exactly what the failure is, the first time so long as nobody disturbs the cars present condition.

    Getting down to nuts and bolts, how much are we talking here? $60? $120?
  • qbrozenqbrozen Member Posts: 32,889
    It isn't wrong, to do the job correctly.

    Absolutely not. And I applaud your OCD habits. I'd be happy to let you work on my cars.

    Its just that my easier and quicker approach works for me so often that I have no reason to do otherwise.

    As you've pointed out in so many posts, it seems that cars come to you AFTER other avenues have failed. So I'd also suggest that your real-world personal experience is skewed toward the more difficult cases.

    '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

  • thecardoc3thecardoc3 Member Posts: 5,741
    edited December 2012
    I know how many that I see that have both had the gas cap attempt, and those that have not prior to their visit.

    If there was any truth to your claim, then I would be seeing 90% of the cars that did not have the gas cap touched leaking at the cap and then I'd get to prove it by the repair routine. The problem is the real numbers just don't line up with your assertion. It does happen that a loose gas cap makes it in the door, and that's about one out of thirty repair events where the cap hasn't been touched that it really is loose. Bad caps (we have emissions testing) are far less frequent.
  • thecardoc3thecardoc3 Member Posts: 5,741
    Do you yahoo? It might be time to try something else..... :shades:

    http://autos.yahoo.com/news/what-that-dreaded--check-engine--repair-will-cost-yo- u-011350043.html?page=1

    Make sure you have time to read some of the comments.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Where's he getting his repair cost estimates? You can't even get an Audi in the front door for $95, much less have someone open the hood.
  • thecardoc3thecardoc3 Member Posts: 5,741
    The estimates are from CarMD. That's part of how they advertise their toy tool. They get peope to write "articles" and throw numbers around with no real explanation of how they were arrived at, nor provide any real correlation to another consumers vehicle issue.

    Then they turn around and do everything they can to try and promote their tool as a savings device when it really can't do any more for the consumer than take the same blind guesses similar to the gas cap debate that we just went through.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Well you know how anecdotal evidence works---when the person guesses right, he brags about it and gets a reputation as a problem solver---when he guesses wrong, nobody's counting the "misses", only the hits.

    Fact is, if you're right 50% of the time, that's the same as coin-flipping!
  • thecardoc3thecardoc3 Member Posts: 5,741
    edited December 2012
    Well you know how anecdotal evidence works---when the person guesses right, he brags about it and gets a reputation as a problem solver---when he guesses wrong, nobody's counting the "misses", only the hits.


    Well if that doesn't sum up the battle that we are fighting, nothing does. Time and again we have to deal with the results of a lucky guess that cannot be duplicated, nor relied on when a customers time and money is really at stake. We have to take a professional approach each and every time, no matter how much we are pressured to do otherwise. When we give into the pressure that rewards the guesses, we quickly lose and then look like we don't know how to do our jobs, (justifiably). When we insist on doing the job correctly from start to finish we get treated like we are rip-offs while someone else who allegedly guesses correctly is a god compared to us.

    That all get's summed up in these two lines.

    We cannot be wrong both ways.

    (There has to be a correct routine and its professional application is the one that I support.)

    AND

    It is't wrong to do the job correctly.
  • explorerx4explorerx4 Member Posts: 19,250
    09 Escape is suddenly hard to start and when it does, it turns over slowly.
    Tried it out, remote works fine.
    Turn key to start, nothing for a couple of seconds, then turns over slow and starts.
    I shut off climate and radio.
    Took a 1/2 mile drive to my mother's to drop something off.
    Got back in to drive home and it started a bit easier.
    Taking it to work tomorrow and bringing my jump box.
    I'm thinking battery.
    2023 Ford Explorer ST, 91 Mustang GT vert
  • explorerx4explorerx4 Member Posts: 19,250
    Took the Escape to work today and it had a tough time starting when I first started it this morning and again after I started it after putting some gas in it a few minutes later.
    Went to the dealer around 11 am to buy a new battery and it was still reluctant to start.
    After the 15 minute ride to the Ford dealer to buy a new battery, it started right up when I left to go back to work.
    After work, it started right up and after stopping at a store on the way home, it started right away again.
    After letting it sit in the garage for an hour, it was hard to start, so I replaced the battery with the new one, and drove it according to the battery replacement procedure in the owner's manual.
    Parking it outside tonight and should know if the issue is the battery tomorrow morning.
    2023 Ford Explorer ST, 91 Mustang GT vert
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    If this occurs again in the next few days, you'll probably have to check for a parasitic drain and for a weak alternator.
  • explorerx4explorerx4 Member Posts: 19,250
    It started fine this morning, but I'll have to keep my eye on it.
    Hopefully, the battery is it.
    2023 Ford Explorer ST, 91 Mustang GT vert
  • thecardoc3thecardoc3 Member Posts: 5,741
    Another shop towed a car to me that they have been trying to get to start. It wa cranking fine, and occasionally when first cranked it sounded lie it was going to start, and then simply stayed only cranking.

    Testing showed that it was losing spark.
    The codes that they said the car was setting were P0340, and P0011. Both have camshaft to crankshaft timing implications. The cam and crank sensors themselves were replaced during the past year and had for a while resolved a hard starting issue. When the car came back with the same codes, the sensors were replaced again but this time it didn't fix the car.

    The reason that didn't fix the car is because the timing chain has jumped and the sensors are reporting the timing of those components for exactly where they are, out of sync.

    This owners driving habits, combined with his oil change history have caused this engine to sludge up, and that starved the timing chain for lubrication and it has stretched. The car loses spark because the PCM is seeing the cam and crank "out of time" and it's trying to prevent further engine damage. Now it needs torn down to identify just how bad the damage is, and it may need to be replaced. He's obviously upset at this expense and can't understand why his engine has failed. Afterall he did what he was told by "experts" and he stopped changing his oil every 3000 miles. The problem is his habits should have had him changing his oil in the 3000 mile range, and he still needed a much better product than one that only met API and ILSAC.
  • steverstever Guest Posts: 52,454
    Did you pull the valve covers or the pan to look for sludge? Or both?
  • thecardoc3thecardoc3 Member Posts: 5,741
    I have only diagnosed the failure, and used my borescope to look inside the valve cover. It's cleary sludged up and after talking to the owner he's admitted to about six oil changes in the time he has owned the car.

    That's neglect, and the failure is a direct result of that.
  • steverstever Guest Posts: 52,454
    I've been wanting one of those for years for peering into wall cavities and the like. The consumer ones have gotten pretty cheap.

    Back in the Toyota gel days, Toyota tried to blame the owners for not changing their oil, although many swore they did exactly what the manual required. Last I heard, Toyota redid a bunch of oil passages in the engine. My memory is foggy but seems like there was something about the overall design that starved oil to the upper part of the engine during a cold start.

    Some cars do seem to be more affected by sludge than others.
  • imidazol97imidazol97 Member Posts: 27,132
    > foggy but seems like there was something about the overall design that starved oil to the upper part of the engine during a cold start.

    IIRC, they also changed the PCV system to be more effective along with changes in the oil flow to or from the heads. There were hot spots in the heads.

    >Toyota tried to blame the owners for not changing their oil, although many swore they did exactly what the manual required.

    If the car company says to follow the oil service indicator system for oil changes, then is a customer at fault for following it? IIRC, toyota ended up honoring repair/replacement costs for oil sludge gel problems if the customer had changed once per year as indicated in their manual.

    Another factor is the quality of the oil used. It was my suspicion that because several of the toyota sludge victims had the oil changed at the dealer, that the dealer was using bulk oil that not the correct quality as required by toyota's standards for oil.

    2014 Malibu 2LT, 2015 Cruze 2LT,

  • thecardoc3thecardoc3 Member Posts: 5,741
    Another factor is the quality of the oil used. It was my suspicion that because several of the toyota sludge victims had the oil changed at the dealer, that the dealer was using bulk oil that not the correct quality as required by toyota's standards for oil

    The API and ILSAC ratings do not meet the needs of most of the engines built since 2004. That's why manufacturers have reponded with their own specifications, such as GM's dexos1 specification. Toyota took it on the chin because the oils being used didn't meet the engines needs. They easily could have voided the warranties but chose to take care of the customers instead.

    Toyota did in fact revise the PCV system which resulted in lower flow, and that in turn allowed condensation of the blow-by gasses under cold operating conditions. That condensation results in crankcase acid production which attacks and breaks down the oil as soon as the oils ability to control the crankcase acids fails. That causes the gelling, or sludge.
  • steverstever Guest Posts: 52,454
    I'm still not convinced; can't imagine GM has better tribologists than the API or Exxon/Mobile. Dexos1 certification still smells mostly of marketing to me, like Top Tier gas.
  • qbrozenqbrozen Member Posts: 32,889
    what's the make, model, and mileage?

    '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

  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    How did you determine a slipped timing chain, for certain?
  • thecardoc3thecardoc3 Member Posts: 5,741
    I'm still not convinced; can't imagine GM has better tribologists than the API or Exxon/Mobile. Dexos1 certification still smells mostly of marketing to me, like Top Tier gas

    And here is where the consumer has the biggest problem. Exactly what are you basing your perception on? Have you been to formal training with regards to the subject? How many engine repairs have you performed throughout your life? Have you demonstrated to the consumer that you have training and experience through something even as minimal of a standard as ASE certiification? (Which BTW this requires training well beyond that standard)

    Maybe I should word those questions another way. Aren't you really just parroting what someone else has said who claimed to have knowledge about the subject, who may easliy have just been parroting someone else, who themselves really at the least had no formal training, or heaven forbid had their own personal reasons for preaching as they were?

    Oil companies have an intertest in a one size fits all standard, it's cheaper for them to produce and creates a significant return on their investment.

    Vehicle manufacturers employ people who are experts at their own area of specialization. They definately do know what their products require and publish the specifications for their products to which the oil companies can choose to meet and certify their products requirements, or not. Just meeting the API and ILSAC ratings (which are controlled by the oil companies) does not guarantee that an oil will meet ALL of the requirements for any given engine.

    There are companies who make products that they certify to meet a manufacturers specifications. They also sell products that only meet the API and ILSAC ratings and correctly identify those as doing so. Why is this so difficult to understand?

    A statement like "Meets the warranty requirements for engine protection of GM4718M" means that the oil meets some of the requirements but fails to meet the full specification. If an oil fails to meet the full specification, then it's the wrong oil for the car you are trying to put it into.
  • steverstever Guest Posts: 52,454
    edited December 2012
    Neither work in a vacuum and the engineers at GM talk to the oil guys, just like they talk to the tire guys and all their other suppliers. The car engineers hopefully aren't pulling stuff out of thin air but are relying on these people who have expertise in their niches.

    I just trust the certifications set by the oil guys more than the guys at GM. They work with most all the engine manufacturers and should know stuff that individual manufacturers may not. I don't want to see Honda oil or GM oil or Toyota oil on the shelf as my only option (especially since often that stuff is a mainline product with another label slapped on top of it, and they charge a lot for the label).
  • thecardoc3thecardoc3 Member Posts: 5,741
    I just trust the certifications set by the oil guys more than the guys at GM. They work with most all the engine manufacturers and should know stuff that individual manufacturers may not

    ACEA. In a word that's why you need to pay more attention to the manufacturers than the oil guys. The manufacturers in Europe (which includes GM, Ford, Toyota, and Honda as well as the major Euro's) long ago realized the only way to ensure that their customers got products that met their vehicle's needs was to have their own standards.

    A 5W30 that meets ACEA A1/B1 is a product that vastly exceeds anything that only meets API and ILSAC, but isn't a long life oil.ACEA A5/B5 is a long life oil. Meanwhile a 5W30 that meets ACEA A3/B3 A3/B4 is a "thicker" oil that meets the European manufacturers requirements, an A1/B1 A5/B5 is too thin for them.

    I don't want to see Honda oil or GM oil or Toyota oil on the shelf as my only option

    You may not want to see that, but the system that we have had in place has forced this to occur, and it started way back in 98 with BMW.

    Ford was the first North American company to have specific specifications that exceeded API and ILSAC, and they were follwed quickly by GM, and that was back in 2004. So not only are you still wishing for the past, your some eight years behind on the simple subject of engine oil, which if we refer back to some of the articles right here in Edmunds that are not correctly informing the consumer about today's vehicle requirements.
  • steverstever Guest Posts: 52,454
    edited December 2012
    Another reason why I don't own a Bimmer. :P

    Consumers do pay attention to this stuff and that's one reason why oil change intervals have been extended. We don't want to go to the dealer every three months and we don't want to have to buy branded oil or coolant or whatever. Not to mention that the FTC frowns on tie-in sales, so the manufacturers have to be careful that consumers aren't too limited in their choices.

    Most of what we drive are appliances and we don't expect to have to treat them like aircraft or Formula One cars. Nor do we want to.

    And what was the sludged car?
  • thecardoc3thecardoc3 Member Posts: 5,741
    Consumers do pay attention to this stuff and that's one reason why oil change intervals have been extended

    Yea, the oil change interval thing is all about a consumers preferance and it has nothing at all to do with catalyst lifespan, and 35mpg cafe ratings....tic.

    We don't want to go to the dealer every three months and we don't want to have to buy branded oil or coolant or whatever

    That's easy, don't buy a car and you won't ever have to deal with any of those concerns.

    Not to mention that the FTC frowns on tie-in sales, so the manufacturers have to be careful that consumers aren't too limited in their choices

    That's why Toyota didn't force their owners to have to use an oil that exceeded the API and ILSAC ratings, and do you see what they got for doing that? The problem was never with them or their engines, it was the oil not meeting the engines requirements.

    Most of what we drive are appliances and we don't expect to have to treat them like aircraft or Formula One cars. Nor do we want to

    Well that's where the automobile is headed. They aren't going to get 50mpg and still have safe relable cars without significant jumps in technology. Car's were never an appliance and it didn't do any consumers right by pretending that they are. Car's are machines, and machines need regular service.
  • steverstever Guest Posts: 52,454
    So, was the sludgemobile a '98-'04ish Chrysler/Dodge? Same era Hyundai or Saab. Or VW?
  • thecardoc3thecardoc3 Member Posts: 5,741
    2004 Nissan Altima 2.5l
  • steverstever Guest Posts: 52,454
    My Nissan's VG33E V6 is much better than that QR25DE 4 cylinder. :D
  • xwesxxwesx Member Posts: 16,756
    I came up with a reasonable solution to the OCI vs. oil life problem. I use oil analysis to determine an optimal OCI for my car given my vehicle, driving conditions, and oil type. That way, I don't have to guess as to whether my engine is healthy and being properly protected by the oil that lubricates it.

    On an entirely separate note, I haven't had any issues at all with my Forester's battery since disconnecting that trailer wiring harness and recharging the battery. Assuming no more issues this winter, I'm going to have to do some more testing on that wiring come spring. But, at least my car starts reliably for now. Many thanks to Doc for the guidance (on that and in general). I'll have to drop some cash in his tip jar when I go through PA next September. ;)

    Merry Christmas, folks! I'm sure many are beginning their holiday travels, so stay safe out there.
    2018 Subaru Crosstrek, 2014 Audi Q7 TDI, 2013 Subaru Forester, 1969 Chevrolet C20, 1969 Ford Econoline 100, 1976 Ford F250
  • thecardoc3thecardoc3 Member Posts: 5,741
    How did you determine a slipped timing chain, for certain?

    Once you understand it, which takes a lot of studying, and then the investment for the pressure transducer set-up and a state of the art oscillosope it's pretty easy.

    I uploaded some screen shots from my scope on my facebook page. These compression waveforms are taken engine cranking, engine running, and snap throttle. The ones you will see on my page are cranking and I used them to demonstrate a new routine that I figured out to everyone else.

    When we first learned to use the pressure transducers, the fellow who figured it out felt that the cranking waveform wasn't reliable to determine valve opening/closing events. That is because you have to have manifold vacuum to create specific cylinder pressure changes during parts of the engine's cycle. A few months back I realized that all I need to do to get sufficient vacuum when cranking the engie that won't start to see all of the valve train events was to restrict airflow into the engine. In the case of the Nissan, I could do that with my hand over the throttle body inlet.

    It worked beautifully, then it was simply a matter of measuring out the waveform that the cylinder produced. The exhaust cam timing should be slightly advanced on this engine as compared to other engines. On the captures it looks like its real advanced because with it cranking the engine is turning slow enough that the rise in pressure in the cylinder caused by the exhaust valve opening completes before we reach BDC. Then the cylinder pressure drops after the intake storke starts, but not until the exhaust valve closes. The next part of the waveform that is critical to show exactly what the problem is occurs at the point where the cylinder pressure starts to rise in the cylinder as we have the compression phase. That doesn't occur until 76 degrees of crank rotation after BDC. That's retarded, it should have occurred about 30 degrees after BDC.

    Here is my page.

    http://www.facebook.com/john.gillespie.127648
  • thecardoc3thecardoc3 Member Posts: 5,741
    Almost forgot, I also grabbed waveforms of the cam and crank sensor signals, both cranking which shows the cam signal really distorted because of the chain slop allowing the cam to not be held in time, I also disconnected the cam sensor, which allowed the PCM to turn the igition system on and let the engine run. The PCM shuts the igition system down if there is a cam/crank sync issue to try and protect the engine from further damage. Once the engine was running, capturing the camshaft and crankshaft signal waveforms allowed them to also be compared to known good captures, and that again proves that the intake cam is out of time.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Where are the pressure sensors located when you're cranking?
  • thecardoc3thecardoc3 Member Posts: 5,741
    Right on the hose that would usually attach the pressure gage to the cylinder. One of the important differences is this hose does not have a schraeder valve in it, that allows the transducer to sense everything that is occurring in the cylinder.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    How could this system be fooled?
  • thecardoc3thecardoc3 Member Posts: 5,741
    How could this system be fooled?

    I don't understand your question.
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