Tag Archive for: diagnostic

A Tough Day for an Honest Mechanic

Hey folks! I want to first apologize about no post yesterday. I really hate the days where I don’t get a post out for you. Today I want to explain what a bad day for a mechanic looks like. I really what you guys to understand that I am NOT bitching about my job. I have committed to be 100% open and honest with everyone. That means that you get to hear the good, and the bad!

This is what a rough day looks like.

After doing a few easy jobs I pulled in a 2011 GTI. The concern was that the fans would run for a long time after shutting the car off. Depending on the length of time, this can be normal. I pulled the car in the shop and sure enough the cooling fans were running full speed even with the key off. The car had been sitting for a few hours, so i knew the engine was not hot enough for the fans to be on.

One thing to note, the check engine light was on. The customer made no mention of the light. On the surface that might not seem like an issue, but it puts me on a high alert. If they didn’t say anything about the light, what else are they not saying. Again, this might not be an issue, but I usually wonder why nothing was said. I guess another point would be, why didn’t the service advisor ask about a check engine light.

After some initial checking, I found that the car had a code stored in the engine computer for the fan, and for another emissions part. Since I was looking at 2 different issues, I had to start somewhere. I started with some very basic diagnosis, checking fuses, checking grounds, the battery. Didn’t really find an issue. I will save the boring “how to” of all the checks that I did, but lets just say, I checked a lot of stuff.

During some of the tests, I noticed that some things were not right. The ECM has tamper proof bolts from the factory, this car had regular bolts installed.The wiring harness looked like it had been tampered with. We had no luck getting a hold of the customer to find out if anyone had looked at the car. I removed the ECM and found that the wires had damage to the outer coating. It looked like someone had poked holes in them to test. This is a HUGE no-no especially on small wires. Now all the red flags were flying. It was time it figure out what the heck happened.

I checked the cars history at the dealer. It only had 1 service completed there. Then I checked the history at VW. It had 2 repairs that were NOT done at my dealer. We can only see what parts were replaced in the VW history. It turns out the ECM(engine control module) and the BCM(body control module) were both replaced about 2 months ago. ~The BCM controls almost everything non-engine in the car. It is a very important module.

So, that explained why the bolts were wrong and the wires were messed up, but didn’t help with the issue. We called the dealer that replaced the parts, they simply said it was because the car would not start. Back to diagnosing, I started checking into what was done at the other dealer. That lead me to checking the ECM coding. VW modules have different “programming” based on equipment. This ECM has what is known as long coding. It is 7-10 bytes, each has 8 bits. The 8 bits are represented by 2 characters(confused yet?).

The ECM installed in the car did not match the the number of bytes that is had when it was built. It might sound like a bad thing, but now I have something to go with. It was time to call VW technical help line. It is what we use when we need more help fixing cars. I wrote a post about what happens when a mechanic can’t fix your car a while back. It talks more about tech line. 😉 I called the folks at VW. After going through the basics, I told them what I found with the coding. I was on hold for about 10 minutes. The guy from tech line came back and said, “Forget about the coding, if you had looked at the part numbers, you should have known they were different”. Basically telling me I should have known it was fine.

He gave me some some things to check, and got rid of me as fast as possible. It was the classic, “Get him off the phone because I don’t want to deal with this problem.” The best part was, the test he gave me made NO sense. It would be like testing the battery to figure out why a tire is flat. After an annoying conversation with tech line, I decided to repair the bad wiring and go from there. During the entire time of working on this car, I could not shake the feeling that the ECM was the problem. There are times when it is cut and dry the module is bad, but MOST of the time it is a dice roll.

After fixing the wires, I was pretty much back to square 1. I loaded up the repair manual and spent some trying to find the common issue. VW repair manuals are populated by VIN. They should be specific to the car. Wanting to make sure I had all my bases covered, I started doing more wire checking. As I am looking at the wiring diagram, I find wires missing.

TADA~ wires are missing. Wait, how can wiring be missing? It turns out, the wiring diagram for that car is WRONG!!! The car was built 10/10, but the wiring harness must have come from the future. The diagram matched a car built 12/10. Thanks wrong information. Now with the proper information, I found that ECM was not sending the signal out properly. Ordered 1 ECM. I will update when the part comes in.

So what lessons can we learn here?

  • Well, I know I could have shaved some time off this diagnosis, by focusing on 1 issue at a time. I was sort of all over the place with it.
  • There are times when information is WRONG. (I am still mad about this)
  • checking history is important
  • Go with your gut. This is the most important part of the whole list!!!

Well, there you have it folks, a tough day for a mechanic. YIKES! Don’t forget to follow me on Facebook and Twitter. I prefer twitter, but I am on both a fair amount. I wish that FB would fix their mobile interface.

If you want me to stop complaining about fixing cars, click one of the share buttons below. That will show me 😉

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Throwing Logic Out The Window, Readers Story

Happy Friday everyone! I am sitting enjoying a nice day off, sipping some coffee, and hanging out with the family. Today I wanted to follow up with a post I wrote a while back. It was several stories about throwing automotive logic out the window. One of comments on that post was from Garrett. He told me that he had a similar story when working on his Jetta.

Garrett sent me that story and I wanted to share that with you today.

On my way to taking my daughter to cheerleading, about a mile after driving, my 96 2.0l Jetta started bucking and surging pretty heavily. Almost to the point of stalling. It would buck/surge then stop and do it again over and over.

It did this most of the time between 1-4000 rpm. I looked it over briefly and didn’t notice anything obvious. I then tried disconnecting the MAF sensor and driving it, changed the effects slightly but still did it. Next i did the same with the throttle body and got the same results. I then took it to a mechanic friend of mine and left it at his shop while i went to work.

After work i stopped back and he had the diagnostic check list printed out for the throttle body. He had checked the levels of each prong with a voltmeter and came to the conclusion it had to be the throttle body. During my investigating i noticed the check engine light didn’t come on when i unplugged the MAF, and it was also coated in engine oil which had leaked all the way down into my air filter from a gummed up pcv so now im under the conclusion i prolly need a new MAF sensor AND a throttle body…ouch!

My next step was google’ing it and asking my fellow vw buddies and vw pages on facebook for help or advice (how i came across Humble Mechanic, you also thought TB from my explanation) So knowing i was due for a tune-up anyway i decided to go against my friends advice and my own gut and do the tune up first. I spent about 300 bucks on plugs, wires, cap an rotor, ignition coil, fuel filter, air filter, vacuum lines and some cleaning sprays (maf cleaner and tb cleaner).

I did the tune-up and stripped my intake apart cleaning everything from intake manifold to sensors to piping and TB. So finally when i was done i crossed my fingers and went for a test drive! IT WORKED! It drove like brand new! For the next 2-3 days anyway! Haha. Then suddenly it started again! I was baffled and angry! So just when i was ready to give in and buy a
new TB and MAF sensor i got a text from a friend who i questioned about my issue.

He said check my fuse panel cuz his mk4 golf burned out the entire fuse panel one by one causing his car to go crazy. I thought it was a far shot but what the heck. I popped the lower dash panels off and started checkin wiring. After a couple mins i decided to look under the hood one more time. 10 minutes later i was back to the thought of ordering a new TB and MAF.

Suddenly I caught a glimpse of a damaged piece of wire shroud or wrap on the main harness next to the distributor. I twisted it around and saw what looked like 2 exposed wires from rubbing, but i was kinda dirty so i grabbed a can of spray and cleaned it up. Sure enough there were 2 barely exposed wires! I traced them back..1 to the MAF and 1 to the TB!!!! S.O.B! HAHA

So i wrapped em um with some tape and hopped in the car…it once again drove great! So i used some zip ties and some more tape to prevent
it from rubbing on the small threads coming off a metal heater line. Over the next few days i was leery, expecting it to start up again…but much to my joy it hasn’t ! All that over 20 cents of tape and 2 zip ties! I couldn’t believe it!

WOW! Thanks so much for that story Garrett! Let me put into Garrett’s story into prospective. If he would have continued on the path to replace the throttle body and MAF, be would have sent over $1000 on parts. $1000 that would have done nothing to fix his car. Imagine how mad he would have been if that happened.

I actually remember talking to him about the issue. Based on what he was finding, all signs were pointing to a throttle body. I have seen mechanics in my shop get beat up over this exact problem. I remember I had a MK3 GTI that the turn signals were acting strange. Turns out it had broken wires in the same spot. I think I stumbled across it the same way that Garrett did, GETTING LUCKY!

If you have a story about your car, feel free to share it with everyone. Just contact me and I will post it!

Ok, we have a few “housekeeping” things to wrap up.

  • I am still looking for a project name for the 1988 Cabriolet I got yesterday. Post a comment of what you think we should call this project. I will pick one, and send that person a cool VW something
  • On Monday, my internet was messed up. I really want to get to know the community better, so I put out a few questions for everyone. If you didn’t post a comment, head over and check it out. I REALLY want to give this stuff away. Oh, I will pay shipping too.
  • Have a GREAT weekend. Really, do it!

If you have ever been stumped, or got your butt kicked by a problem, you can get revenge by clicking one of the share buttons below.

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MFI display in VW EOS

Shop Shots Volume 13 Insider Pictures of Automotive Service

Hey everyone! We got some more Shop Shots today. I am really starting to LOVE doing this post, I hope that you guys enjoy reading it as much as I do writing it!!

MFI display in VW EOSNow, if you just looked at this picture, you would say, “Charles, there is nothing wrong here. The back doors are just open”. HAHA, I would have to agree with that statement, but here is the real story. A customer brought their car in because the battery was dieing. When the advisor went out to the car, she found that the rear doors were showing open. Where is gets awesome is, this car is an EOS. The EOS is a 2 door convertible car. It doesn’t have rear doors.

I am not sure what the tech found wrong. I am suspect of the drivers or passenger window motor/module. That or a coding issue. When I find out, I will update everyone

Volkswagen KeyI am not really sure that everyone can appreciate how hilarious this is. A co-worker of mine brought this to me. It is a VW key, that has a battery terminal as a “fob” of “key chain” or something. I would bet that they hide it under the car somewhere, but I am not really sure. The worst part was, it was all sticky and gross. I would have loved to unwrap the tape to show you guys. It would have been cool to ask the customer why they did that.

Volkswagen EOS top in service position

I posted this to InstaGram, but I wanted to show everyone this. I got this car in last week. The customers concern was the top would not work. It had some faults stored in the module for the top. The cool thing is, our VW scan tool is we can activate almost everything remotely. There is a procedure that will allow me to open and close the top. It SHOULD work no matter what. I could not get it to open the top. I had to trick the module into thinking it was working correctly so I could force it open.

With the top open, I could put it into a service position. That extends the trunk, and allows access to almost all of the components of the top. In the “Behind the Wrench” interviews I do, I ask “what job would you not want to do again”. This would not be my #1, but it is up there. This top has about 30 sensors that monitor the position of the top, windows, doors, vehicle speed, trunk, and so on. This is really one of the most sophisticated parts of ANY VW!

I actually had another picture I was going to post, but I think I will save it for next week and dedicate an entire post to this picture.

In other news, I FINALLY found my project car. I will take some pics and write a full post about it tomorrow. All I will tell you today, is that it is a Cabby. 😉

Don’t forget to sign up for email updates. That is the best way to make sure you never miss a new post. Also, I have a YouTube channel. Maybe instead of pictures, I will take a video of the project. You can make sure you connect with me by using the icons on the right side of the page.

If you are SUPER excited that I finally found my project car, spread the word and clicky clicky one of the buttons below.

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Check Engine Light OBD II

What Does Your Check Engine Light Really Mean?

Most of us know that, “BEEEEP” from your car, followed by that little amber light, that looks like an engine with a lightening bolt in it. Or maybe even the phrase, “Emissions Workshop” showing in the instrument cluster. But do you know what it means when your vehicles check engine light comes on? Understanding what your check engine light means can save both headache and wallet-ache! Before I get into what a check engine light means, let’s talk about what it is, and why we even have it.

All cars from model year 1996 and newer are set to a basic standard. That standard is known as O.B.D II, short for On Board diagnostic second generation. It basically says that all cars will meet a certain standard when it comes to diagnostics, they include

  • A standard connector to hook up a scan tool. This is so all shops can gather the same information.
  • Standard(ish) location for the connector, called a Data Link Connector or DLC for short
  • Standard codes, basically if a VW has a failed sensor, and a Honda has a failed sensor, they must use the same code to describe the fault, more on that later.
  • There are more standards, but they have to do with communication rates, and more things that do not really matter.
  • Also, the light itself has a standard(ish) look to it.

    VAS 5051B Volkswagen scan tool

    Here is the VAS 5051B hooked up to an EOS with a top issue

When your check engine light comes on, it means the cars engine computer sees an issue. The issue can be anything from a loose gas cap, to engine timing being wrong, or some crazy wiring issues. I could go on for days and days about all the ways that the check engine light can come on.

When you bring your car to have the codes checked, I would hook up a diagnostic tool. I generally prefer a VAS 5051B. That is the big boy of VW scan tools. I find it to be far more reliable than the other scan tools we have. The information that I get is show like this.

P0420, Catalyst efficiency below threshold.

The “P” code is used to determine what system the fault is. P0420, the P is for power train, the 0 means that a Fuel and Air Metering and Auxiliary Emission Controls fault exists, and the last 3 digits give a more specific system of failure.

Check engine Lights

Your check engine light might look like one of these

There are 3 states of your check engine light.

OFF
If your check engine light is “OFF”, you generally have nothing to worry about. There might be an issue, but it has not happened enough times to set the light. Most issues take 2 failures in a row to turn the light on.

ON
If the light is “ON”, you have an system in your engine or transmission that is having an issue. If your car is driving normal, get it to a service station when you can. I DO NOT recommend waiting for an extended period of time. The longer you wait, the more likely you are to have more issues.

FLASHING
Ok, this one is pretty serious, if the light is “FLASHING”, you need to STOP driving and have the car towed to a service station(I prefer the dealer of course). When the light is flashing, your vehicle is mis-firing. That means the air and fuel is not being used properly. This will cause damage to the vehicle emissions system, and that is expensive.

Some quick advise, if your check engine light comes on, check your gas cap first. It is free, and might eliminate the hassle of bringing your car in for service. Also, if your light is just “ON” and the car runs fine, don’t panic. Just get it fixed soon.

Don’t forget that we have are on facebook. Also, if you hate check engine lights, just click one of the share buttons below, it will eliminate them forever~well, not really but it is worth a shot right 😉

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Humble Mechanic Logo

Throwing Automotive Logic Out The Window

Hey folks, I am back in action today. Got some good stories about automotive logic, and throwing it right out the window. Sorry about missing Friday, but this week will make up for it!!!

There is no doubt that the diagnosis part of this job is one of the toughest. Racking your brain over problems that make no sense, all while trying to relate them to a component failure. It can be enough to make a mechanic lose their mind. Early on in my training, I was taught to always follow a logical repair process. That is a 100% true statement. I would not start diagnosing a tire going flat, by checking the oil. This process is reinforced in our yearly training as well. Of course in a training class, nothing ever goes wrong does it. 😉

There are some basic strategies to diagnosing cars, or anything really. Doing things like “working easy to hard”, “Keeping it simple(stupid), and making sure you are diagnosing the problem not just the concern. if a mechanic follows these simple steps, they will be able to diagnose most issues. This is a lesson that i try to ingrain in all of the young mechanics that come through the shop.

There are times for every mechanic that they get their butts kicked by a car. One of the great things about being at a dealer is we have several layers of assistance to help when a mechanic cant fix a car. Then there are the times that all the assistance in the world doesn’t help, and you have to throw all the logic out the window. The following stories are real. The names have been changed to protect the innocent. There are really no names in the story btw 😉

Beetle Transmission Problems

A customer bring their car in because it was making a horrible noise at about 45mph. The mechanic test drove the car, and did some checking. The thing about transmissions is, failure is rarely absolute. Meaning that being 100% sure of the diagnosis is rare. Usually it takes repairing the concern before you know if it repaired it.

Well, after several test drives, and checks, he decided to replace the transmission. Now, replacing a transmission is not a hard job, but it takes time, is a lot of work, and does not pay really well. It is not something mechanics do for fun! After getting the work done, the mechanic test drives the beetle again. Guess what, noise is still there. Well more checks, and diagnosis follow. The problem turned out to be an 30 second fix. The customer had a Disney ball on their antenna. For some reason, at 45 mph, the ball would catch the wind just right, this would cause a vibration in the antenna, that traveled down into the roof.

TDI Transmission issues

Very similar to the story above. A customer brings their Passat TDI in for a shifting issue. The mechanic drives the car, and verifies the problem. Now this particular TDI engine had just come out, so the information was pretty limited. The mechanic followed the steps he should, and again, decided to replace the transmission.

With a fresh transmission, the mechanic test drove the car. Would you believe that the car drove great, at first! The mechanic let the car sit for a while and test drove it again. Sadly, it was doing the same thing as before replacing the trans. It turns out that the car had a very slightly clogged fuel filter. That small amount of difference in fuel quantity cause the engine to “stall out” when shifting. The only thing felt by the customer and the mechanic was the poor shift. After a new fuel filter, the car was 100% right.

TDI Engine Locked Up

This time, the customer had his TDI towed in, because it would not start. At first it sounded like the battery was dead. The mechanic tried to jump start it, but that was a no go. We towed the car into the shop for further diagnosis. A full starting system test did not reveal anything. The mechanic noted that it smelled like the clutch had burned up. So he removed the starter to check for damage. Didn’t find any.

He attempted to crank the engine over by hand, and was not able to. Even an almost 3ft wrench would not move it. The mechanic removed the valve cover, and oil pan to inspect for internal engine damage. Well, he didn’t find any. We all got to talking, trying to brainstorm and get ideas of what to do next. Just about the time he was going to recommend removing the cylinder head, I suggested that he take the serpentine belt off. That is the belt that runs the alternator, a/c compressor, and power steering pump. When he removed the belt, the engine would turn over normally.

It turns out that the pulley on the alternator locked up. As powerful as a starter is, it was not able to overcome the small pulley. I could not believe that the belt would not just slip over the pulley and let the engine start. I had seen this happen 1 other time, I just wish I would have remembered it before he took the other parts off. As soon as he finishes it, I will update on what happened.

I know there are many more stories just like this out there. If you have one, contact me with the story, and I will share it with everyone. All the repair logic in the world would not have helped in some of these situations. Mechanics need a repair process, but they also need to know when to ditch it and try something random!

If you enjoyed this story, and the site, please share it with someone you like. Lets keep this community growing! All you have to do is click one of the buttons below

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The Internet Can Not Fix Your Car

So you might be thinking, “Why the hell is Charles talking crap about the internet and fixing car”. I spend almost every second of the day working on cars, or working on this site (and some other side projects), why would I say something like that? Heck this community even has its own Automotive Forum.

Well, for one, its true! The internet CAN NOT fix your car. You can not type “replace my timing belt” into Google and expect it to be replaced. That would be stupid right? Well the same goes for everything else. I wish I could count the number of times someone has come in to the dealer and said “Well, (insert website here) said that this is what is wrong with my car”. Oh, and you usually have to say it with a snotty voice. 🙂

Now don’t get me wrong, I think that customers need to be informed. I think the more information that the customer has, the better an experience they will have. Doing research on issues with your car is an important to help from being taken advantage of. I would recommend having the following information.

  • Understand your owners manual.This will also give you maintenance information too.
  • Your service history, Unless you have 1 place you bring your car, always have service information with you
  • If you do find some information about a problem you are having, print it out, and bring it to the repair place. It very well could help gt your car fixed faster and cheaper. Just don’t act like a tool about it.

I rely really heavy on information that customers provide. Researching the issue you are having with your car might help you explain the problem better. Even if it does not apply to the car. I would much rather not need information, than not have it.

I guess what I am saying is it all boils down to attitude. I would like to beleive that when a customer puts a lot of time into researching their car it’s because they LOVE their car. The sad truth is, it comes off like they just want to prove the dealer wrong(sounds like my mother in-law). If you find information that might help your mechanic, PLEASE PLEASE PLEASE tell them. Let them figure out if it applies or not.

Just to be 100% clear, I love the internet. I dig all of the really cool social media platforms(I think Pinterest is about to BLOW up), the amount of information is endless. I used YouTube nonstop when building this site. I had no idea how to do any  of this stuff. I am really thankful for the help I got and continue to get. But I would never expect someone to just do it for me. I studied the information, and did the work myself. That is exactly how it works. 🙂

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What happens when a mechanic CANT fix your car

Every once in a while a car comes around that is sent straight from hell. The crazy problems that keep me awake at night. Things that, if you were a professional writer, you could not even make up. When this happens, having a game plan to crucial!

There are times when we(mechanics) just can’t figure out whats wrong with a car. When this happens we have to take things to the next level. Thankfully this is not something that happens a lot, but when it does, it can make for a bad day!

STEP 1 ~ Ask another mechanic
This is usually the first think that a mechanic does when they can’t figure out a problem. The guys working next to me are a HUGE resource of knowledge. The odds of them running having ran into a similar issue is pretty good.

The other good thing about asking the guy in the next bay is a totally different perspective. They come in with a fresh set of eyes. There comes a point when frustration starts to set in. Getting a fresh pair of eyes, and a fresh mind is always a good choice.

Step 2 ~ Take a break
You would think that this would be step 1, but it usually falls to number 2. If you have asked someone working next to you for help, and could not come to a conclusion, you are starting down an unhappy path. Much like asking someone else, taking a break will gives a chance to clear your head.

Walking away for a couple of minutes is a perfect way to think about the issue while not buried under it. If I smoked, this would be the perfect opportunity to burn one, then come back and reevaluate the problem

Step 3 ~ Computer Research
If you have not fixed a car by now, its time to break out the old repair manual. Depending on what the problem is, VW has several different resources available.

  1. Standard repair manual. ~ This is the (online) book that has information to fix our cars. It contains some information, tests to run on components, wiring diagrams, and some VERY basic how to’s
  2. Scan tools ~ Our scan tools does more than just tell us the faults stored in all the vehicle computers. They have software built in that adds different tests based on the faults. The tests are not the end all of solutions, but it can give some ideas on where to go next.
  3. Technical Service Bulletins(TSB) ~ This is a repair update that is issued by a manufacturer. It can be anything from a tip to fix a rattle, to tips on diagnosing transmissions. They are NOT recalls. Customers will not be notified about them. This is something a mechanic can use to help fix/diagnose a problem. This information is available to anyone that wants it.
  4. Tech Tips ~ This is something that VW issues to us mechanics. It is either the precursor to a TSB, or just a quick tip. Usually a very short blurb about a issue with a car.
  5. Google ~ If 1-4 do not work, Google can be a life saver. There are lots of really sharp people that have put great info on the web. I am not too proud to do a Google search 😉
Step 4 ~ Call in reinforcements
Now that you know your getting your butt kicked, its time to call in the big guns. VW has a program set up to help mechanics when they are stuck on a problem. Its called VW tech line. What we do is, send an email to our VW tech help line folks. We attach diagnostic logs, photos, videos(I have never attached a video), and answer several questions about the issue with the car.
After sending the email, we have to call the guys at tech line and talk to them. They usually ask the very simple stuff like “did you check the battery, did you check this, check that, is the car on fire?”. After the basics are covered, its time to get to business. They have access to all of the cases from VW. They can tell how many times someone has called tech line about this issue, and what they did to fix the problem. It usually takes a few calls to get an issue resolved.
Step 5 ~ Dispatch the top dog 
When all of the above fail, the top dog comes to the dealer. We have a regional guy that travels to dealers to help fix the REALLY broken cars. There is warranty criteria that requires him being dispatched. I am pretty sure I can’t talk about what that is. This is the guy that has all the connections to the really important people in the company.
The guy we have now is pretty awesome. He worked as a VW tech line guy for years. I acutally worked with him years ago, when he was a tech line guy.  This is basically the last line of repair. I have not ran into a car that between the regional guy and myself, couldn’t be fixed.
Step 6 ~ T.M.I.
If it comes to this, its time to T.M.I. or Trade Me In! I heard that saying on CarTalk, btw. I think the more appropriate thing to say is buy back. There is lots of legal mumbo jumbo about buy backs that I really don’t care to talk about. I am mostly just joking around about trading cars in.
More often folks will trade because the repair is too costly, not because I can’t fix it.
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