A lot of the forum posts seem to be a lot of talented fixers and DIYers, but far too often it seems like there's a lot of parts.cannoning going on, even sometimes changing the same part and multiple times to see if they get a different result. I happen to be one that utilizes the tools and documentation available to most of us for most of our vehicles, including this form and others, to actually diagnose things. While I thought this was more than norm, it seems not so and I feel like an outlier in this regard. So I'm curious how many of you are parts. Canon folks and how many actually diagnosed? And if you are parts Canon, why do you operate that way when diagnosis is al.ost always possible to within a degree of certainty. I do understand that sometimes you have to kind of narrow it down and then guess from that point. However, what I don't understand especially is throwing part after part. So what gives?

 

Sometimes it's easier to use the collective knowledge on the forum to point you in the correct direction. A lot of the people on the Forum are a little older and been there done that, and learned the hard way. Because there wasn't information avaiable, like there is today. So they do their best to impart their knowledge to said DIY'er. Unfortunately what gets lost in the communication a lot of the time, is that one little key bit of information, said DIY'er left out, that sends them, and others on a wild goose chase.(changing parts) Those who are not Mechanically inclined or trained as such, sometimes don't know how to word or state an issue, well enough for the "Mechanic / Forum Guru" to correctly comprehend / assume the correct repair. Sometimes the printed word doesn't always convey the correct, or pertinent information. Which is where an Actual conversation can be most helpful. Sometimes the noise heard is a clunking sound to them, and a knocking noise to others. After 50 + years of doing this I have found to listen to them intently, especially most women (not Linor) who may not quite know how or what is happening. But they dang well know it did. So by reading the posts on the forum they gain knowledge that usually helps, but is not always the difinitive answer. Most others (parts changers) are not quite as skilled or don't have the equipment available to them or a friend who is a mechanic to help so they lumber along semi blind doing the best they can with the given information from the forum members, friends, whoever they can find. Even if it is slightly incorrect. Just My Thoughts.

Jack

 

I am with Jack.

Most call me the Fossil, and I dont mind. At 75, who cares.

Yes, been doing that "fixing" thing since the early 60's, and NO money, and 200 miles from anywhere.

I learnt, and failed, and sorted out whatever, Parts, HAHA, what parts, fix what you got, a bit of fencing wire, and away we go till next time.

OK, OBD is a new game, and I dont follow it.
Agree, sounds a very different to each individual, and that makes it hard.

Actual talking, LUV it, and do a lot of around the world.

My current, and recent past, beasts that have OBD, have never been plugged into by me. Something dont work, systematic diagnosis usually finds the fault. Fixing it, oh boy, that can be daunting, but its is only a car after all. Module issues, due to whatever, are rare in the whole scheme from what I have found. Trouble is with replacing a lot of these modules, they are Vin specific, so the system needs to be programmed to accept said module, not a simple DIY that I am aware of, maybe I be wrong.

Like most, I am forced to drive a later car, AKA :Laptop on wheels, and tolerate it. I have about 5 years of driving remaining before the Pollies and their "stuff" take over. The 2 we have will survive, the X400, rarely used and has some hissy stuff "sometimes", and I live with it. The 300c, no strange bells and whistles, or strange lights. It will do what it does.

Diagnosis is a lost art, MOSTLY. NO disrespect, it is what it is.

A V11 turned up the other day, with Pizza, and he was stumped as to where the 12th cylinder had gone. I heard the "crack" of HT spark, and 5A spark plug had a crack in the porcelain, simple fix. He mentioned that 3 "mechanics" had NO idea, one mentioned a heads of look and see, OOPS. He stated that they ALL went looking for the OBD, scan tool in hand. He laughed, and told them, "its a 1985, no OBD, thank God". They were lost.

Coffee time, see ya.

The old stuff, in the care of both kids, are fine. They knew MY way of sorting issues. Well trained both of them.

 

I agree with Jacoba's post.

I had the luxury to have access to a full shop of tools and equipment when I was a young lad, learning from experts who could diagnose issues by sound, smell and visual cues. As I got older, I embraced much of the technology available and being that it is a passion and hobby, actually enjoyed researching not only the vehicles and what makes them work but the tools to properly repair proprietary designed deterrents, reduced allowances/tolerances of the engineering and software to decode the new advancements. Unfortunately, as a hobby, I do not always encounter the quantity of issues to create solid foundations for firm solutions but can only bring past experiences to light which may help others look at a starting point to their situation at hand.

A few things I noticed about phantoms diagnostic codes, when read by some friend who just start using their diagnostic tools, they see the codes individually and jump one at a time to find what needs to be fixed, then swap the parts only to still have issues. They did not look at the complete story the tool is telling which often illustrate a cascading effect from a failed sensor, module, environmental condition or electrical interruption causing a multitude of errors created only by the one random issue not necessarily associated directly with the codes. The addition that many shops/dealerships seem to follow this trend and perform part swaps to trace a problem either for profit or due to inexperienced technicians do not aid in this issue.

Back with 60,70 and early 80's vehicles, it was the norm to just swap parts as there was no computerize components and issues are very obvious. Purchasing used parts for replacement never guaranteed the parts installed were fully operational and buying new parts today does not guarantee quality and reliability. (I recently replaced an OEM parking aid module only to replace it again because the new replacement was defective)

Kevin

 

I agree there are limitations and I am not really speaking to really troublesome problems or advanced diagnosis with specialty tools. However, I dare say that multimeters are cheap and require very little space to use. Voltage drop, open ground, learning to read wire wiring diagrams, etc. Is not really that difficult. Sure it takes some time of course and for some it takes longer for some it takes less time. However, instead I'll give an example. I was reading through an older post probably about a year or two old that struck me to write this thread to begin with. While I see a lot of parts changing here and there, this one was quite astounding. I can't quite recall what the problem was exactly. I think maybe a rough idle or stalling And they had changed the sensor three times. First as a guess, which didn't clear the problem. Then they bought another one, just from a different brand. Still no resolution. And then finally bought a third of yet a different brand. This might sound extreme but what got me to thinking was that it really isn't. Perhaps the third was extreme, but the second is something that happens fairly commonly and I was thinking it's very easy to test most of the sensors using simple multimeters. I get that cars are complicated and for some more complicated than others. I guess my point is that I feel if folks spend a little bit more time trying to diagnose they would save a lot more money and with the added benefit of actually solving the problem probably quicker. I just wasn't sure how many people y'all are in which camp. I guess those of us who can diagnose the problems and solve them probably aren't the ones posting often on the forum. So maybe it just seems like there's more people throwing parts at things.

And I agree, it seems like dealer shops especially are just throwing parts and replacing things that could easily be fixed, which is just absolutely horrendous from a cost standpoint as well.

 

You might be surprised as to how intimidating a multimeter can be to people, I have a neighbor that keeps telling me that it is much quicker to swap out the parts than to sit and learn about the options on a digital multimeter.
I know it will take me a bit longer initially and plan time to diagnose prior to ordering which tends to gain me some ribbing from friends and a few family members. I would say I have just over an 80% success rate for identifying the primary issue. My buddies who swap can do a job in an evening while it can take me just over a day (Remember hobbyist). The difference is after I am done, I am done... they usually had to modify, find a shortcut or damage something to make it work only if they did not break something and then ask if I could help.

I think many are trying to take the steps to be self-sufficient with limited time and resources, they want to learn but don't know what they need to learn and after vaguely learning the basics, does not always understand what they see. Worst yet, as when I was learning some methods, the problem was me, I was not connecting properly and kept getting wrong reading which would lead me in the wrong direction. It took time to understand some of the basics (Only to randomly forget late in the evening and waste a day tracking a phantom)

I'm not of the type that is happy constantly swapping parts and there is very little space in the new vehicles to work while a lot of opportunity for cuts and bruises. I'm more strategic than carpet bomb. This does not mean I'm always right. I'm a lot older, hearing playing tricks, I'm having less patience with the glitches some updated cause on my tablets and I have less liking of crawling, bending and contorting to access security bolts which don't have clearance for removal. I only want to do it once. Others might like the action of being out ripping something apart.

 

I think there are people that want to diagnose before replacing parts.
Much more youtube videos on diagnosing car compared to even 10 years ago to help the average DIYer.
Wish we had the data to really know!

 

I will chime in here. I like to gather data and see what it can tell me. So, like with these cars, I can tell you that for example, if you have a vacuum leak on an X-Type, odds are, it is 1 of 3 parts. (each part is only $10 or so and if it isn't bad now, it will be shortly). So, in this case I tell people to simply replace these 3 easy parts first and then lets see what they have. 90% of the time, their problem is solved. It took them maybe 30 minutes to replace. This is where I use the "parts cannon", but there is some logic with the parts. Now, if they are still complaining about having a vacuum leak, that is where the diagnostic routines come out and a cause/effect is looked for to determine what needs to be replaced.

Now, on the flip side to this, modern day cars have a lot of feedback loops. so, the problem can appear to be in one location, but in reality, it is somewhere else. So, unless you are able to get lucky and get an OBD code to say "the computer sees this component not working properly", you may have to take a wild guess as to what part it is. But, you can approach it with some insight through knowing "this car tends to fail this way". You get a no start condition (engine rolls, does not come to idle) on a newer XJ, the possibilities are endless. But, you talk to the group, a lot of people are going to tell you to look at the fuel injectors first. it is a known failure item in the car. Is that "parts cannoning"? I say no. You have some logic to say, "XX part is bad because ......". Now, you say, replace the fuel pump and you are getting no OBD codes, then I would call that parts cannoning. the difference between the two situations is having some proof of cause and effect for a given model. This logic would not hold true for say an 85 XJ when the data came from 2010+ vehicles.

As for multimeters, i have seen the gambit run with this. I know some people that can tell you butt loads of information from a multimeter (like what is the difference between seeing 0.001 VDC and seeing 0.000 VDC, yes, these tell me 2 completely different stories). I have seen others that you put the multimeter in their hand and it might as well be kryptonite to superman. The ones I fear more are the ones that think they know something and don't (saw the after effects of an "electrician" who put their multimeter on the AMP range and then went phase to phase in a 450VAC panel, lets just say there wasn't much left of the multimeter after it pulled a megawatt of power through it). I get around this general weakness by having people turn on various circuits. In a lot of cars, a single fuse may power 3 or 4 things. You can prove power to things by turning on something else on the same circuit. Sometimes the logic is not obvious unless you have the diagrams, but it is there. Once you have eliminated a few things, pulling out the cannon can be done much more controlled. It isn't a ***** nilly shot in the dark. You have eliminated some of the possibilities.

I guess I run a fine line between fact proven cause/effect troubleshooting and parts cannoning. But, I am normally using a lot of logic in my "guesses". Like with the X-Type. You tell me the rear tires are wearing on the inside edge. I tend to ask 2 questions: 1) are the tires leaning in at the top (this normally tells me that the upper control arm is shot),and 2) I ask them to do a big sweeping turn and step on the gas and ask them if the rear end felt like it was going to step out on them (if yes, then odds are they have a bad lower/forward control arm). Are these the only things? Nope. But, based on how things fail on that car, they are the likely ones. This is part of the logical leaps that I tend to make.

 

What I find to be especially frustrating is having a situation where someone asks me for help, and when I give them instructions on how to diagnose or repair the issue, they don't listen and start going off in different tangents.

I recently had a referral from a friend who is having issues with his gearbox. After accessing the DTCs, I told him he has to replace the solenoid pack to fix the issue. He took the car to a shop and they overhauled the gearbox, but didn't replace the solenoid pack. When he came back several weeks later saying he'd spend 3,000$US on the gearbox overhaul, but still had erratic shifting, I told him to go and discuss the matter with the owner of the shop that he paid.

 

There are those who are (or not) blessed with "The Knack".