13 June, 2018

A Disturbingly Quick ECM Diagnosis. Really Long Story.

An RV filled to capacity with seven women (a grandma, two daughters and four grandaughters) and, I think, six small dogs, came into the shop last night.  It was a 2008 Chevy C5500 with 41,000 miles on it.  The thing still smelled new and there was no corrosion to be found anywhere except the exhaust pipes.  The RV had been well cared for and has been parked indoors during winters.  They called us saying that it was in a speed derate condition.  I think they came out of North Dakota or Minnesota and it had derated soon after departure.  A shop replaced the fuel filter and they went on their merry way.  300 miles later it derated again and that's when they showed up at our shop. 

I grabbed the work order, saw it was a C5500 and thought I had the job in the bag.  Would take a couple of hours, but I thought I would be able to get them fixed up.  One of our regular customers had a small fleet of those trucks and they all suffered, regularly, from the same problem these women were having.  After having them tell me what had happened (always talk to the drivers, shit gets messed up when the information passes from driver, to service writer, to mechanic) I scanned the thing and saw P0101 and P0102.  "This is a slam-dunk fix." I thought.  Then I saw the odometer.

The other customer (the fleet) didn't start having those DTCs and derate problems until the vehicles had well over 100,000 miles.  Those fleet trucks also idled a hell of a lot.  Someone not in the know, see the previous post, would toss a MAF sensor into the truck and call it good only to have the vehicle come back the next day with the same problem.  More parts, same problem etc.  After bashing our heads against the wall trying to figure out what was going on, we solved the problem.  The problem wasn't expected and wouldn't have been looked for, but we figured it out.  What we found with the first fleet truck was a carbon problem. 

All of the trucks in this story have the Isuzu 6.6L "Duramax" diesel engine (the LMM variety I believe).  Let me tell you, the Duramax didn't get the nickname "Dirtymax" for nothing.  They're decent engines and are reliable, but they're a real pain in the ass to work on.  Access to just about everything sucks. 

Try and follow along.  Air entry into the engine starts at the air cleaner, passes through the filter, past the MAF sensor (air intake temperature sensor and MAF sensor are one unit), through some ducting, into the turbo, out of the turbo, more ducting, through the CAC, more ducting, through the intake air valve, through the intake heater, through a small manifold where the EGR valve is also connected then finally into the engine.  Towards the end of that path is where the problems were found.

The little manifold bolts on top of the EGR valve.  The two ports which allow the exhaust gas into the fresh air intake are about 1" by 2" (25mm by 50mm) and the dirty-ass exhaust puts a LOT of carbon through those ports.  With the first fleet truck those two ports were completely blocked and the intake down into the engine was about 1/3 blocked.  I piled up all the carbon I dug out and it amounted to a ball (non-packed) of about 4" (100mm) in diameter.  Once clean and reassembled, the problem was gone.  Well, until the carbon built up again.  The next time we ran into those DTCs, a quick shove of a bore scope down the intake, a cleaning, done.  Every now and again the carbon build-up would cause the EGR valve to fail, but that was an easy test.  Use the scan tool to command the EGR valve to different positions throughout its range, a look at the values (commanded/desired position should match actual position) and if the numbers matched, EGR valve was OK.  If the numbers didn't match a new EGR valve was needed.  So, after all of that experience I thought the RV would be no different.

The RV, as mentioned earlier, only had 41,000 miles on it.  I did the EGR valve check and it was fine.  I pulled the pipe from the CAC and stuck the bore scope down the intake tract.  Sooty, slightly oily (normal) but no carbon build-up to speak of.  Exhaust wasn't restricted (air flow through the engine is the name of the game here), air cleaner was OK, ducting OK, CAC OK...  Well, I guess the diagnostic procedure had to be run through. 

I started with P0101 and not far into it a list of DTCs was given and if any of those were present they had to be dealt with first.  That's quite normal.  When faced with a number of DTCs, you pick the active DTC with the most occurrences and start there.  P0102 was one that had to be dealt with first and I then got that procedure.  I suppose I should explain diagnostic procedures.

When I was in tech school, these procedures were called flow charts because that's what they were.  Search Google for "flow chart" and you'll see what they are.  Start at the top, answer the "yes" or "no" questions (lots of testing involve in this by the way.  Voltage and resistance measurements etc.) and you'll end up with a solution.  The people who create these flow charts are really good at it, most of the time they're spot-on, but they're not infallible.  Most of the flow charts end up with one of two things.  "Replace ECM" or "Contact manufacturer".  It's very rare to get that far, especially contacting the manufacturer, but it does happen on occasion. 

ECMs are expensive.  We recently replaced an ECM in a 2006 KW that has a Caterpillar C13 and our cost for the part and it's programming (we don't have the capabilities to program Cat stuff) cost a little over $3,000.  When you're the mechanic doing the troubleshooting, you don't want to be wrong.  Replace an ECM only to have the same problem means you missed something early on.  A disappointingly large amount of mechanics don't go through EVERY step of the flow charts.  Generally speaking, if someone says an ECM is bad and they have less than an hour of diagnostic time into it, they didn't do what they should have. 

Troubleshooting start with basic stuff.  Visual inspection for corroded terminals, broken/burned wiring, missing components, damaged components etc.  A little further in and the ECM and sensor connectors will be disconnected, resistance checks done.  Those terminals and wires have to be identified and confirmed, the connectors have to be removed, wire colors or numbers identified... it takes a lot of time.  You want to be sure that the pin you stuck a meter probe into is the correct pin.  Sometimes you get to "replace ECM".  I go through the whole flow chart a second time just to be sure I didn't fuck up somewhere.  As I go through the flow chart I tick off every step I do and, if a measurement of some sort is called for, I write that down right on the chart.  If I get to "replace ECM" again, well, I guess the customer is getting some bad news.  If the second run through ends up at another solution I go through for a third time. 

The flow chart for this RV was alarmingly short.  Sometimes you run into a short one.  Scan, "Are any of these codes active yes/no", inspect intake for loose clamps... inspect exhaust for... monitor MAF sensor PID is the value within so and so?  Measure resistance at pin 2.  Is the resistance greater than five ohms?  If yes, repair circuit.  If no, replace ECM.  I was startled at how quick ECM replacement came up.  "That can't be right at all.  I missed something somewhere." I said out loud not realizing all these women were watching the whole time.  So, I ran through it a second time.  Replace ECM.  A third time wound up at the same spot.  "Ma'am, I have some news for you."

I hate telling nice people that they're going to be stuck in place for days and will be giving us a lot of their money.  I explained the fleet trucks and that their problem should be a carbon build-up problem but I wound up at ECM replacement three times.  She asked me some questions, I gave answers, she asked how much an ECM would cost and when we could get one, I paused awkwardly. 

"Well, it would probably be a couple thousand but I don't know for sure.  All the dealers are closed for the night."  Her tanned face turned white.  I then had to tell her that new ECMs are blank and required programming, programming involves programming fees, new ECM probably won't be in stock...  She asked where the nearest dealer was and I said "Just across town.  They'll probably open up at 08:00.  You're welcome to camp out in the parking lot if you choose to stay here tonight.  She went inside the RV and they all had a pow-wow.  She comes back out and says they have to be at a dog show, two states away, by 08:00 the next day. 

"What will happen if we keep going?  Will it derate again?  Will the engine be badly damaged?" she asks.  I can only say "I don't know.  The engine will most likely derate again, but I don't think the engine will be damaged.  You will be going through some not-so-nice parts of a couple of big cities though.  At night."  She then asks me what I would do.  I'm always a straight shooter with customers even if they don't want to hear what I have to say.  "I would call the dog show a bust and be at the dealer first thing in the morning.  The safety of my family would be my first concern.  You may make it just fine, but it could also go very, very wrong.  If my decision to try and 'make it through' resulted in harm to my family... I wouldn't want that on my conscience.  A dog show comes around every year, family only once." 

They had another pow-wow.  The lady came back and said they were going to try heading down the road.  "OK, I'm going to make it clear on the invoice that it was your decision to try and make it." I said.  They paid the bill, went out back to have dinner and when I looked out again they were gone. 

I hope they make it and that the dog show was worth it.

26 May, 2018

Find An Engineer

In modern terminology I'm a mechanic.  I'm not fond of that name, but it's what the general public knows me as.  In the Victorian and Edwardian eras I would have been called an "engineer" and I quite like that term.  Let me equate the mechanic/engineer divide with something you may have more experience with, the medical trades.  A modern mechanic would equate to a CNA.  A Victorian engineer would be a full-on MD.  I feel that I've earned the right to call myself an engineer.  When you consider the shop classes I've had, my time spent in tech school, the years I've worked the trade and the other related things I've studied on my own time... I'm an engineer.  The average "mechanic" these days is usually a parts replacer.  Sure, some computer stuff comes into it, but the average mechanic isn't going to understand much of it.  Connect the scan tool, see some code for some part, replace the part, didn't work... The job then goes to the older guys.  The engineers.  The guys who have bothered to learn how things actually work and why.  The parts replacers are concerned about beating book time so they can move on to the next job and beat the book time there.  It's about making money.  Concern about the actual cause of the problem and the customer are secondary. 

You've probably experienced that kind of scenario.  The "check engine light" (CEL) comes on in your car, you take it to a shop, the shop you've always gone to for oil changes and brake jobs, it's "fixed", you give them your hard-earned money and go on your merry way.  Two days later, that damned CEL comes on again.  You go back to the shop and explain your situation.  Turns out it's the same problem you had the first time 'round.  You don't get billed for the labor but you'll have to pay for some other part.  You go on your way again and... CEL comes back.  Another trip to the shop, you raise hell (rightfully so) and they promise you it will be taken care of this time.  Third time's a charm, right? 

You drop your vehicle, in the morning, for a third time.  Noon comes and you don't hear anything from the shop.  The previous two visits you had heard back from the shop around lunch time.  15:00 rolls by and you still haven't had a call back.  You call the shop for an update and get some generic explanation and are informed that your car will have to remain at the shop through the next day.  You're pissed (rightfully so) because you now have to find a way home that day and also get a ride to work the next day.  That third evening you're fuming.  You have the shop's Facebook page open and have already written a scathing review, but have yet to click the "post now" button.  You're angry, you've been in a pickle because you don't have any wheels, you think "All they have to do is hook the (it's always "the" instead of "a") computer up to it and they'll know what's wrong?"  Allow me to throw that back to you.

Let's say you're the VP of a local brewing company.  What if I told you your job just involved showing up in a company polo shirt and looking into large vats?  What if you are a network engineer and I told you your job was just moving cables from one place to another and sitting in front of a computer all day?  You would probably be thinking that I have no clue as to what your job entails and that I was an idiot for not knowing.  Well, then, don't go assuming about my job.  You may have a batch of beer that is completely wrong, you make corrections, the second batch is better but not quite right.  The stations in one part of the building may go dead, you make some tweaks and some stations start working, you make more tweaks... Your mechanic is no different.

Here's what's happening at your shop.  The first time you drop it off with a CEL complaint, the first available mechanic may (or may not) verify the CEL is on.  A scan tool of some sort gets connected (with the appropriate "connection" fee, those scan tools are expensive) and the mechanic sees some sort of codes.  The mechanic will do some quick reasoning and recommend replacing some sort of sensor/part.  The service writer calls you for approval and you, not knowing shit, approves the "repair" (which is a "most likely" kind of guess, but you don't know that) and you're picking up your car only to have the same problem a day or two later. 

The second visit to the shop, the same mechanic is going to be given the job (Yay!) and that mechanic will spend more than ten minutes "diagnosing" the problem.  Whatever part seems most relevant will get replaced.  You pick up your car, no charge for the labor but you do have to pay for the part.  A day or two later the CEL comes back on.  Same problem.  You're really pissed now.  You give the service writer a piece of you mind and leave the shop with steam coming out of your ears.  The service writer is now sick of having some raving bitch/lunatic asshole reaming them up and down, so the job is picked up and handed directly to the "old guy".  The "engineer".  The guy who spends his lunch breaks doing crossword puzzles and pondering the operation of triple expansion steam engines.  The puzzle solver.  Every decent shop has that guy.

The "old guy" has probably read a lot more books than you, the fancy-pants executive, have read.  You, the six figure executive, can't figure out why your lawn mower won't start (it's out of gas), while the "old guy" has already mowed his lawn and is reading a book about England's "Black Country".  But that doesn't matter.  You have a university education.  These mechanics are obviously not competent and you should get all of your money back.  The "old guy" disagrees, but won't tell you how much of an ass you're being.  The "old guy" will smile, tell you what he thinks the problem is and then offer to show you what he's found.  The "old guy" knows you're pissed, he's been in the business long enough to know how fucked up it is, but he wants you to be involved in the process.  He wants to show you why, and where, your money is being spent.  The "old guy" will be completely honest with you, "This is going to be really expensive..." and he'll let you make the decision.  You wonder "Why the hell didn't this guy work on my car in the first place?"

Repair shops aren't much different than other businesses.  Except for the flat rate system.  Imagine you were a building contractor and were asked to provide an estimate to put an addition on a house.  You would take the time and materials into consideration, allow a little buffer etc.  Now imagine that some organization had already made that estimate for you.  That organization said you could bill twenty hours for that addition.  You look at the house, the steep roof angle, the shitty grading and think "I can't do that in twenty hours?"  Well, welcome to the flat rate system repair shops operate under.  Times are provided for almost all automotive repairs and that's what the mechanic gets paid for.  If the job bills three hours, the mechanic gets paid for three hours.  Even if it takes him eight hours to do it.  The mechanic would lose a LOT of pay.  Conversely, if the job pays three hours and it's done in one hour, the mechanic gets paid for three hours.  It's a fucked up system that has only widened the gap between customer and mechanic.  The customer and the mechanic both want to come out ahead.  Doesn't always work that way. 

Your first visit to the shop is the mechanic rolling the dice.  Throw some parts at the problem and it may work.  Mechanic comes out ahead.  Second visit, the mechanic is trying to break even so he spends a bit more time and throws another part at it.  No good.  You're back for that third, "old guy" visit.  The shop knows you're a regular, they don't want to lose all of those money-making oil changes and brake jobs, so they appease you.  The job goes to the "old guy". 

The "old guy", the "engineer" knows that the shit has hit the fan and the problem has to be solved come hell or high water.  He bothers to take the time to actually follow the diagnostic procedures for whatever problem turned that CEL on.  It takes time to go through those procedures.  You've met the engineer, he's shown you what he's found and he's explained to you what needs to be done.  "I'll need to have your car for another day.  Is that okay?"  You may even get a call from that engineer the next day, explaining the problem he found, the repair involved and (roughly) what it will cost you.  The "old guy" will have already figured out the cost of labor (realistically, not book time) and parts so as to give you an honest answer.  You complain about the frustration of the first two visits (rightfully so) and that the problem should have been fixed the first time (think about your own job and your own success rate) and the "old guy" is just saying "yes sir/yes ma'am I understand.  Sometimes these problems aren't quite so cut and dried...."  You calm down a bit, reluctantly give approval, you don't expect anything to be different...  You pick up your car the next day, pay the bill for a few parts, a can of brake cleaner and some zip ties... but only half an hour of labor.  You know the "old guy" had to have spent more time on the job than half an hour.  What gives? 

The "old guy" had been paying attention to the job from your first visit.  He knows the younger guys are all about the money.  He knows they don't have a clue about the long-term survival for a shop.  The "old guy" bills half an hour because he knows the other mechanics should have figured shit out.  He wants you to come back.  The "old guy" knows once you've found a mechanic you "trust", regardless of whether or not they're the "cheapest" mechanic in town, you'll come back for more work. 

The "old guy" knows how things are supposed to work.  He understands how electricity works, he understands the basic physics of hydraulics (can't compress a liquid), but the "old guy" was a parts replacer at the beginning of his career.  Tech school can only teach so much.  The rest is on the individual.  The good engineers are constantly reading, constantly wondering "how does that work?" and constantly learning anything they can.  Always learning.  Sure, they have to make money.  Families need to be cared for.

You're going to go through a lot of mechanics and parts replacers before you find the "old guy" engineer, but once you find that guy, stick with him.  He may not be the cheapest, but your money will be well spent. 

24 March, 2018

Thoughts And Prayers

One thing I learned while dealing with my Dad's death back in '94 was that "I'm sorry" or "I'm sorry for your loss", when heard repeatedly, becomes meaningless.  A more modern, and meaningless, saying is some form of "Thoughts and prayers...."  I heard "I'm sorry for your loss" so many times that I resolved to never say it to anybody who has lost someone important.  During that trying time as I heard the "I'm sorry" so much I thought "Why the hell are you apologizing?"  I understand that the intention was good and, despite the saying making my skin crawl, it was appreciated.  These days, when someone has to deal with a loved one dying, Facebook is awash with the "Our thoughts and prayers are with you..."  Oh, just go and fuck your hat.  The words don't mean jack shit.  You want to support your friend when they've been knocked down?  Here's some suggestions.

Take some food to them.  Your friend and their family are going to be adrift and have temporarily lost their "normal" world.  A simple casserole taken to them as they go through the myriad of things involving funerals and such will speak volumes. 

Mow their lawn, rake their leaves, shovel the snow as the season demands.  Again, taking some task off their already overloaded minds. 

If you're only seeing the bereaved at the funeral, look them in the eye and just give them a hug.  Alternately a hand shake and pat on the shoulder.  A little bit of human interaction from someone who is "outside of the loop" will remind them that people who care are still among the living. 

Offer to help organize stuff.  "Don't worry about the flowers.  We'll load them up and bring them over to your place tomorrow."

Offer to transport people as needed. 

Just be there, hanging out in the background.  When you see the sniffles start and tears start to fall, be there with the tissues.  You see someone trying to get a phone number from a family member they haven't seen in forever... *Bam!* you're there with a pen.  The simple act of being near and making your presence known helps a lot. 

If you're not near to the bereaved, send a freakin' card.  Yes, by snail mail.  You send a card and the recipient has a tangible thing, a personal thing, to hold onto.  If you have a poignant photo of the deceased that might make the survivors smile, send it.

Your fucking "thoughts and prayers" don't do anything.  Your actions are what count.

04 November, 2017

Hull Number 401

Forgive me for geeking out in this article, but I wanted something I could direct people to when the subject comes up.

RMS Titanic.  Yes, I'm one of the "Titanic" people.  I dislike the term "Titanic Fan" as that is a rather derogatory term.  I also wouldn't call myself a Titanic "historian" because, when compared to actual historians, I don't know squat.  I also don't like the "Titanic enthusiast" term.  I'm an "armchair historian".  I read books, a lot of books and also watch any documentary (even the preposterous ones) that I can get my grubby paws on.  Despite my self-imposed "armchair historian" status, I know a lot more about Titanic than the average Joe/Jolene.  Allow me to share my background regarding Titanic.

My gateway to Titanic was not Walter Lord's book "A Night To Remember".  The spark that lit the fire was a model.  In the summer of 1982 I was about ten years old, my sister was getting married and, after the rehearsal, dinner was held at a place just outside of town.  I don't know if the place was "for hire" or if the place was owned by friends, but it was a rather nice house.  There was an indoor swimming pool at ground level and the second level, a mezzanine you might say, had some tables and a "U" shaped bar.  Along one of the walls sat a large model of this ship.  Black hull, white superstructure, four funnels...  I had been interested in ships from a very young age because my Dad had been in the Navy.  His "bluejackets manual" was one of my favorite books and still is.  Being the inquisitive child I was, I asked an adult about that model.  I was told it was the Titanic.  That model captured my attention even though I had no idea what "Titanic" was besides some ship.  After that was all said and done, I did what people used to do when they wanted to know more about something back then.  I walked downtown to the library and searched the card catalog for "Titanic".  I found one book.

I read Walter Lord's "A Night To Remember" in just a few sittings.  I just couldn't put that book down.  Once the book was finished I returned it to the library and forgot about Titanic.  Just a few years later Dr. Robert Ballard found Titanic.  The first I knew about it was from the cover of National Geographic (Dad had a subscription).  I remember holding that magazine in my hands, staring at that classic photo, almost not able to process what I was looking at.  Of course, I dove into that magazine like a boy possessed.  I hadn't realized it until that day but Titanic had its hooks in me.  I wanted more information, I craved more information.  We didn't have cable TV, we didn't have internet...  That issue of National Geographic was all I had until much, much later in life.  I did find a book in the early '90s, Charles Pellegrino's "Her Name, Titanic", which I devoured.  Now that I think of it, I should read that book again to see how it compares to what we know of Titanic now.  After the discovery of the wreck there was a bit of Titanic mania but nothing like what was to come.

I saw James Cameron's movie with my best friend in the theater while visiting, oddly enough, my Sister over Christmas break '97.  I had known a movie was coming out and was chomping at the bit to see it.  It didn't help much that the game (Mac and PC on the same discs) "Titanic: Adventure Out of Time" came out the year prior to Cameron's movie.  I played the hell out of that game.  I watched the movie, bought the VHS version as soon as it was available and revelled in the mass quantities of information that were spewing forth.  The movie, as good as it was, created a monster.  The movie created... Fans.

I believe that if James Cameron had had a free hand and unlimited resources, he would have put out the best documentary anyone would ever see.  Unfortunately, that would have been a financial disaster.  At that time, the audience for an "in theater" Titanic documentary would have been rather small.  Expeditions to the wreck are not cheap.  Before the movie "Titanic" as we now know it, and the mania that surrounds that movie, there's no way Mr. Cameron could have raised enough money to pay for an expedition to Titanic for just a "documentary".  I think Mr. Cameron, sort of, had to put the Jack and Rose love story into it just so it would sell.  And sell it did.  There is definitely a line which marks pre-movie and post-movie.

Pre-movie, if I had started talking Titanic, I would have been looked down upon as a huge dork.  Post-movie I could, pretty much, have a Titanic conversation with almost anyone and appear as if I were an expert (LOL).  The post-movie hysteria died down and the general public pretty much forgot about Titanic again.  But the historians, enthusiasts and idiots like myself kept right on with it.  The growth of the internet helped quite a bit.  Encyclopedia Titanica is my favorite website.  I urge you to visit and peruse the wealth of information available there.  The research articles are my favorite part.

One research article on Encyclopedia Titanica turned my view of Titanic on end and caused me to view that ship's story from a completely new vantage point.  That article was "Acquitting the Iceberg" by Peter Elverhoi.  That article made me realize a lot of what I considered "fact" in regards to Titanic was simply myth that has been perpetuated throughout the decades.  From that point on, I would only considered actual facts.  Things said about Titanic without proof were pure speculation.  Guesses.  This new view of Titanic led me to the documents which, to me, are the basis of what we know about the night Titanic sank.  The inquiries.

I've read the US Senate inquiry and am only 1/4 through the British inquiry.  The British inquiry seems less of a witch hunt than the US inquiry but the US inquiry started immediately after survivors reached New York.  If there was an attempt to cover anything up, it would have been weak at best.  There simply hadn't been time to organize a cover up.  The survivors were scattered, some simply vanished into America, there was no way to organize a cover up.  That being said, I think some of the crew were probably covering their butts and may have left out certain details.  They wished to remain employed after all.  Details of the disaster can vary greatly from witness to witness.  Especially times of events.  The only times I would trust are from the witnesses who expressly stated that they had taken notice of the time.  When you read the inquiries, try and forget what is currently known about Titanic.  The biggest sin a person can commit when researching Titanic is to look upon the whole thing from a modern perspective.

A person researching Titanic must be wary of the marketing wank that is spewed forth to sell stuff.  Overly dramatic "documentaries", conspiracy theories, speculative facts...  I've watched many, many documentaries.  Sometimes I learn something new, sometimes I watch an hour-long program only to realized nothing of what was said can be proven.  The things that are know about Titanic are few.

Since this article is getting to be quite long, I will continue in Part 2.  If you have any questions, please feel free to comment.  I may not respond right away, but I do check in regularly.

22 August, 2017

Another New Guy: Redux

In this post I, pretty much, degraded the "new" (at the time) guy to the point of being a complete idiot and a failure as a wanna-be mechanic.  Well, I have been feasting on humble pie for some time now.  The guy went to the day shift for about four to five months and then got moved back to night shift.  I don't know what happened during his time on day shift but he's not the same.  Maybe it was getting some good experience while among more mechanics than just grumpy me.  Maybe something "clicked" in his head.  I don't know, but he's much better.  He's not as much of a slob either.  He's got a new tool box, lots more tools and he seems to take pride in them.  All of this was plain to see within a few days of coming back on night shift.  He's also getting a formal education at the local tech school.

I stand corrected, I'm impressed and I now think he's going to do okay in this field.  How wrong I was back then.