I presume as a salaried employee that he does. Surely having someone "try" to fix it is a lot better than getting a bill for $108 shoved in your face.
Hand that vehicle to a flat rate employee to investigate, and not charge for it means the flat rate employee get's shafted. Of course there would be the obligatory promise (that doesn't have to be kept) to find him/her some gravy to make up the time.
So just how much time and effort could someone really need to spend when one of these kinds of problems isn't able to be solved by common knowledge? BTW I posted one of these about a Corvette about year ago. The customer didn't un-pair their original phone so the system wouldn't learn the new phone. The tech who solved the problem, which also included downloading an app onto the customers cell phone didn't get a dime for his effort.
That's a textbook example of being penny wise and pound foolish- when our service advisors run into a communications or telematics issue they call me; if I can fix it or isolate the problem there is no charge to the client.
Do you get paid while you do that whether you fix it or not?
Yes.
Mine: 1995 318ti Club Sport-2020 C43-1996 Speed Triple Challenge Cup Replica
Wife's: 2021 Sahara 4xe
Son's: 2018 330i xDrive
I presume as a salaried employee that he does. Surely having someone "try" to fix it is a lot better than getting a bill for $108 shoved in your face.
Hand that vehicle to a flat rate employee to investigate, and not charge for it means the flat rate employee get's shafted. Of course there would be the obligatory promise (that doesn't have to be kept) to find him/her some gravy to make up the time.
So just how much time and effort could someone really need to spend when one of these kinds of problems isn't able to be solved by common knowledge? BTW I posted one of these about a Corvette about year ago. The customer didn't un-pair their original phone so the system wouldn't learn the new phone. The tech who solved the problem, which also included downloading an app onto the customers cell phone didn't get a dime for his effort.
So basically the dealer either shafts the tech or the customer---take your pick? GREAT business model!
So basically the dealer either shafts the tech or the customer---take your pick? GREAT business model!
That's one of the real "secrets of" the automobile repair trade that none of the experts ever told the consumers, and it doesn't stop there.
Complain about diagnostic fees until they are removed, or try to get them waived if the work is done and the tech doesn't get paid for the time that was spent to prove what was wrong with the car.
Get assistance from the manufacturer for a repair and the tech now gets the warranty rate for the repair instead of the customer pay rate, which can quite often be as little as half of the hours that they would have been paid for the same work.
With as many times as this has been bounced around everyone should know by now that the percentage of time that a gas cap causes a check engine light is less than 1%. So why are they making this demonstration? IMO, It appears they assuming" that "you" don't know any better. Then they double down on possibility with their oil change commercial. First they use a clown in front of a shop to push the 3000 mile services (Question, What are they really saying about the shops that they want to do business with and sell parts to?) and then they try to suggest that the person that wants you to have to buy a new car (a dealer) is only pushing a 5000 mile service as if that will ruin your engine. Isn't it something how they ignore the fact that the consumer doesn't need their system if the car a consumer owns has the maintenance reminder system built into it? It's comical seeing them try to split hairs with their 3750 mile recommendation as if even that is ever correct, and not be specific about exactly what oil is being put into the car in the commercial.
Here is the oil change commercial. So how many of today's cars call for 10W40?
Well, no one cares about what they are really saying with those ads? I can see servicing someone's car and telling them they can go for up to a year, or until the maintenance light comes on before it needs to be done again. Then have them see one of these commercials which is telling them they can't go 5000 miles and have that lead to confusion. There would be no shortage of people who would roast a technician if he/she didn't get the details right for the customer, so why is there silence when a business like AZ is clearly wrong with their message?
They are cutting up on shops and techs with some of their messages surely that must mean they are the authorities, right? (ret)
It really rubs the wrong way when they advertise like this, and then turn around and try to seek our business.
Sorry Doc, not a video guy so I didn't sit through them.
Not to change the subject on you, but this is fresh in my mind:
“Software updates are extremely important to me,” said another Tesla owner, Scott Wolf, a software engineer in Naples, Fla. “Knowing there are new features and they can fix the car without having to bring it in — that’s very impressive for an owner.” (NY Times)
Just wait till they start charging for them. They can put any price on that too since there is no competition. For that matter, that software engineer should be familiar with EULA's and how they only give someone a license to use specific software for a period of time and then have to be renewed, for a fee. He get's to enjoy the side of the equation where other people have to pay over and over again for his stuff even if it didn't change. I wonder how he is going to like being on the paying side. I'm betting that he won't find that impressive......
The article also talks about GM and their updates via wifi and to Doc's point, Ford is anticipating going John Deere and letting you turn features on for a price.
Just like the Sirius/XM radio in your car.
I think the real point is that people don't like taking their car in to the shop and that's part of the reason why over-the-air updates will quickly gain traction.
Well, no one cares about what they are really saying with those ads? I can see servicing someone's car and telling them they can go for up to a year, or until the maintenance light comes on before it needs to be done again. Then have them see one of these commercials which is telling them they can't go 5000 miles and have that lead to confusion. There would be no shortage of people who would roast a technician if he/she didn't get the details right for the customer, so why is there silence when a business like AZ is clearly wrong with their message?
They are cutting up on shops and techs with some of their messages surely that must mean they are the authorities, right? (ret)
It really rubs the wrong way when they advertise like this, and then turn around and try to seek our business.
I think you are reading way too much into what the AZ "message" really is here---the actual message is:
"We know what we are doing and we base our advice on factory specifications, not upsells or guesses".
Whether you believe that or not is another matter entirely.
But then, these AZ commercials are not directed to the likes of those here who are Forums regulars.
Well, no one cares about what they are really saying with those ads? I can see servicing someone's car and telling them they can go for up to a year, or until the maintenance light comes on before it needs to be done again. Then have them see one of these commercials which is telling them they can't go 5000 miles and have that lead to confusion. There would be no shortage of people who would roast a technician if he/she didn't get the details right for the customer, so why is there silence when a business like AZ is clearly wrong with their message?
They are cutting up on shops and techs with some of their messages surely that must mean they are the authorities, right? (ret)
It really rubs the wrong way when they advertise like this, and then turn around and try to seek our business.
I think you are reading way too much into what the AZ "message" really is here---the actual message is:
"We know what we are doing and we base our advice on factory specifications, not upsells or guesses".
Whether you believe that or not is another matter entirely.
But then, these AZ commercials are not directed to the likes of those here who are Forums regulars.
To me, they are saying "we are the only ones who don't have a hidden agenda." Really? You have no desire to sell parts or service? OK, sure.
'11 GMC Sierra 1500; '98 Alfa 156 2.0TS; '08 Maser QP; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '11 Mini Cooper S
I think the real point is that people don't like taking their car in to the shop and that's part of the reason why over-the-air updates will quickly gain traction.
Over the air updates aren't going to fix the Dodge Ram Cummins for the guy I was just on the phone with. In fact visits to a the dealer and another shop he described as well as his purchasing and installing two instrument clusters (that he bought online) so far have failed to solve the issue. I don't expect that this will even be an event worthy of writing up a case study for a training class but have to wonder just where would he be if he hadn't found me.
Then again it's not a stretch to figure out where he would eventually be without someone that can fix what he has right now. He would be buying a different one and that is what this is really all about. The people who are waiting for him to buy a new one don't want someone out there that can fix what he already has at any price.
A cluster problem? That should be easy, since the dash will go entirely digital. Then "self-repair" the sensors and reboot, and you're done. If the screen gets smashed by your 4 year old, then you may have to get the glass replaced.
There's an idea that might just work. Have them sell the license to allow you to make parts on a 3D printer. I can imagine they would want about a Mil for the license and then a surety bond so that you will be liable for any issues anyone has down the road with your parts.
This is why we might be heading toward Stever's clinically emotionless modular replacement world of Car Repair.....by default....since no person in their right mind will want to be an automotive mechanic as the career continues to lose its appeal.
There are a few questions that I would like to see the answers to. One would be whether any of the people who ever felt they had to be critical of the people working in the trade had any idea just what their efforts were really going to accomplish. They may have meant well, but what they really contributed to was making it even less likely for the trade to attract the people that it needed who could learn to be great techs. Then again who knows? Maybe that's what they wanted to accomplish from the beginning.
I'm talking about people like Mr. Reed when he was involved with NBC, and all of the other articles that were more about tearing down and never offered anything constructive to put back in. Their activities are a piece of the picture as to why so many of people in the trade advise others to do something else with their lives. I suppose they will balk at the idea that this is part of the results of their efforts "to protect the consumers" but that doesn't change the perception from this side.
$100/hour is still very high and that's where independents are running in Southern California. For example, even with prevailing wage and labor compliance in CA, construction workers (skilled journeyman) are still only about $75/hour and that includes all fringes, benefits, add-ons, taxes, fees (all-in).
So is it $25/hour for the building and the lift? Can't charge for tools as construction workers have those too.
'18 Porsche Macan Turbo, '16 Audi TTS, Wife's '19 VW Tiguan SEL 4-Motion
I think part of the problem is that many young people attempt a career in auto repair because they really like/love cars. You don't see this so much in say plumbing or HVAC. So my point is that the potential for disillusionment is greater than in many other trades.
$100/hour is still very high and that's where independents are running in Southern California. For example, even with prevailing wage and labor compliance in CA, construction workers (skilled journeyman) are still only about $75/hour and that includes all fringes, benefits, add-ons, taxes, fees (all-in).
So is it $25/hour for the building and the lift? Can't charge for tools as construction workers have those too.
Building/land Tools/equipment not provided by the mechanic Consumables (cleaners, etc.) not included in parts prices Wages for the service advisors Partial wages for cashiers, office manager, and other related staff Office equipment & services (PCs, copiers, internet connection) Customer lounge costs (land, TV/cable connection/WiFi, coffee, mag subscriptions) Insurance Overhead for write-offs/good will work Marketing Possibly loaner vehicles
I think indies in northern California are in the $135/hr range right now--at least the specialists are. Most of the shops I know don't have service advisors, lounges, and most are renters.
I've never used a shop without a customer waiting area.
Then you wouldn't have used mine. I had to choose, either spend money on a waiting area, (on a building that I didn't own) or spend that money on tools, software licenses, schools, service information (and on, and on).
How about mobile mechanics, they bring the service, maintenance, and repairs to the parking lot at your place of work.
Like any fractional, some have the potential to be outstanding, and some unfortunately can undo all of the good the entire trade produces. Anybody in this forum can declare themselves a mobile mechanic tomorrow morning and try their hand at it. You don't have to have any real experience, or a license. You can own minimal tools and just try and pick the lowest hanging fruit. You also wouldn't have to worry about taxes, insurances, training, or even the environmental impact of your efforts. All you have to do is be cheaper and just good enough and you get a free pass, heck you might even be praised as a hero for saving someone money that they would have had to spend at a shop.
500 miles from home,,,, almost anyway,,, pulling a long hill in eastern NY my Escape seemed to be laboring. Upon cresting the hill there was a noticeable vibration when the transmission shifted into sixth. Forcing a down shift the vibration stopped, releasing the throttle allowed it to shift back to sixth and the vibration returned. Pushing the descent button forced a shift to fourth raising the engine speed from 2200 rpm at 65 to 2800 and the vibration was gone. Hmmm, not good. 176K leaves for a few possibilities but at that point there was no MIL, only the notable vibration. I still had a lot of ground to cover, and with no other symptoms at that point in time I chose to press on.
What I was feeling was a misfire which was being caused by the PCM shutting one of the injectors off, but I didn't know that for certain yet. But why was it misfiring? After stopping for fuel and restarting at idle the misfire that I suspected was obvious. Manipulating the throttle to change engine load and speed the misfire could be compensated for. One of the tricks that takes a long time to learn is how to use the throttle to change spark voltage demand to see if a misfire is spark leaking outside of the cylinder. To do that requires changing engine speeds and loads in a way that result in varying spark advance and cylinder air/fuel ratio's. While the misfire could be mitigated with engine speed and load, it did not respond to advanced spark timing and richer mixtures. Hmmm, worse than not good.
With the fuel stop and engine restart the system now did code and generate a MIL. I had to drive it attentively to respond to the few times that the PCM wanted to flash the MIL. There was no way this wasn't going to hurt the catalyst, the question was how much was it going to be damaged. I made it to the class location and grabbed a scan tool, P0302 and a P0300. During the break we did a fast ignition coil test (had spark), spark plug inspection and a quick swap between cylinders #2 and #3. The misfire remained with cylinder #2. That was the limit for what there was time for as well as the tools on hand but it was enough to know it wasn't going to be an easy fix.
After the class it was time to limp it home. A quick test by disconnecting the injector confirmed the vibration exactly as it felt at times noting prior to that, there were times that it didn't display the vibration with the injector connected. That confirmed that when the misfire was the worst it was either the PCM shutting the injector off or the circuit failing. If the PCM detects enough misfires it shuts the injector off to try to protect the catalyst. The rest of the trip home needed to be a balancing act between speed, load transmission gear range to mitigate the number of misfires that ultimately occurred. Getting it to the shop confirmed what I suspected especially since the initial discovery occurred with pulling a long hill. It lost compression in cylinder #2, burnt exhaust valve.
Oh well, not a big deal in my book because my Escape has a lifetime guarantee. If it breaks in my lifetime, you can guarantee that I'll be the person fixing it. These things aren't anyone's fault and all the care in the world can't prevent every possible failure, so it comes down to just deal with it. But I did grab one photo as I pulled it apart. Here are the cams and the top of the cylinder head. I still might do the chain and guides while this is apart, but there is no scoring of the cam gear faces from the chain at all. There isn't even any play in the chain so it is completely serviceable if I want to leave it. That is really impressive when you start to put the numbers to all of this. I'm at 176K. At 180K the crankshaft will have turned on average about 4 billion times.The injectors and coils would each have fired about 2 billion times. The pistons have traveled some 8 billion strokes at 100mm per for a total distance of some 497,000 miles worth of sliding against the cylinder walls, each. To face a repair, and not a full rebuild is an amazing feat IMO and just goes to prove, they really don't build them like they used to.
Oh well, not a big deal in my book because my Escape has a lifetime guarantee. If it breaks in my lifetime, you can guarantee that I'll be the person fixing it.
So why didn't you just do a compression test right after you pulled codes and did the swaps between cyl 2 & 3? By then I suspect you knew what was up.
I was still 250 miles from home with just enough tools to do what we did. Once I proved that it wasn't spark then the only choice was whether to tow it home or just go ahead and drive it. There was still testing to do which officially was the compression test before this could be considered diagnosed but yeah I pretty much knew what was up within about fifteen seconds after first feeling the vibration that was engine speed and torque convertor clutch dependent.
Did you even suspect the torque converter lock-up at that point?
Why would the misfire go away on a certain type of downshift...is it that the increased revs generate just enough compression for the cylinder to fire? (I'd suspect about 80 psi would be required).
So why didn't you just do a compression test right after you pulled codes and did the swaps between cyl 2 & 3? By then I suspect you knew what was up.
I was still 250 miles from home with just enough tools to do what we did. Once I proved that it wasn't spark then the only choice was whether to tow it home or just go ahead and drive it. There was still testing to do which officially was the compression test before this could be considered diagnosed but yeah I pretty much knew what was up within about fifteen seconds after first feeling the vibration that was engine speed and torque convertor clutch dependent.
Hey! You can't just start guessing! You have to follow the diagnosis protocol!
Why would the misfire go away on a certain type of downshift...is it that the increased revs generate just enough compression for the cylinder to fire? (I'd suspect about 80 psi would be required).
That's exactly what I was working out. When a cylinder is losing compression it takes a certain amount of time for the charge to drop low enough to cause a misfire. The faster that the engine is running, the less time there is for the leak to impact the cylinders peak pressure.
The PCM is able to detect misfires that the driver cannot because to the PCM a misfire is the failure of the crankshaft to accelerate sufficiently between 20 to 130 degrees rotation after TDC. That means the cylinder could fire and not necessarily slow the crankshaft, but not actually accelerate it inside of the window. When that happens the strategy is to shut the injector off to try and protect the catalyst, and that resorts in a full misfire that is easily felt.
At idle running compression is typically half of the cranking compression. In a class I often have the techs try and explain why that is. Any ideas? When tested my cranking compression was 44psi, the compression at idle was 65 psi. Normal cranking compression should be in the 190 psi range so my idle compression should have been between 85 and 100psi.
Comments
So just how much time and effort could someone really need to spend when one of these kinds of problems isn't able to be solved by common knowledge? BTW I posted one of these about a Corvette about year ago. The customer didn't un-pair their original phone so the system wouldn't learn the new phone. The tech who solved the problem, which also included downloading an app onto the customers cell phone didn't get a dime for his effort.
Mine: 1995 318ti Club Sport-2020 C43-1996 Speed Triple Challenge Cup Replica
Wife's: 2021 Sahara 4xe
Son's: 2018 330i xDrive
Complain about diagnostic fees until they are removed, or try to get them waived if the work is done and the tech doesn't get paid for the time that was spent to prove what was wrong with the car.
Get assistance from the manufacturer for a repair and the tech now gets the warranty rate for the repair instead of the customer pay rate, which can quite often be as little as half of the hours that they would have been paid for the same work.
With as many times as this has been bounced around everyone should know by now that the percentage of time that a gas cap causes a check engine light is less than 1%. So why are they making this demonstration? IMO, It appears they assuming" that "you" don't know any better. Then they double down on possibility with their oil change commercial. First they use a clown in front of a shop to push the 3000 mile services (Question, What are they really saying about the shops that they want to do business with and sell parts to?) and then they try to suggest that the person that wants you to have to buy a new car (a dealer) is only pushing a 5000 mile service as if that will ruin your engine. Isn't it something how they ignore the fact that the consumer doesn't need their system if the car a consumer owns has the maintenance reminder system built into it? It's comical seeing them try to split hairs with their 3750 mile recommendation as if even that is ever correct, and not be specific about exactly what oil is being put into the car in the commercial.
Here is the oil change commercial. So how many of today's cars call for 10W40?
They are cutting up on shops and techs with some of their messages surely that must mean they are the authorities, right? (ret)
It really rubs the wrong way when they advertise like this, and then turn around and try to seek our business.
Not to change the subject on you, but this is fresh in my mind:
“Software updates are extremely important to me,” said another Tesla owner, Scott Wolf, a software engineer in Naples, Fla. “Knowing there are new features and they can fix the car without having to bring it in — that’s very impressive for an owner.” (NY Times)
Edmunds Price Checker
Edmunds Lease Calculator
Did you get a good deal? Be sure to come back and share!
Edmunds Moderator
'11 GMC Sierra 1500; '98 Alfa 156 2.0TS; '08 Maser QP; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '11 Mini Cooper S
Just like the Sirius/XM radio in your car.
I think the real point is that people don't like taking their car in to the shop and that's part of the reason why over-the-air updates will quickly gain traction.
"We know what we are doing and we base our advice on factory specifications, not upsells or guesses".
Whether you believe that or not is another matter entirely.
But then, these AZ commercials are not directed to the likes of those here who are Forums regulars.
'11 GMC Sierra 1500; '98 Alfa 156 2.0TS; '08 Maser QP; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '11 Mini Cooper S
'11 GMC Sierra 1500; '98 Alfa 156 2.0TS; '08 Maser QP; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '11 Mini Cooper S
"The iPhone--works pretty much the same as any other phone, but costs more because it's prettier, has a nice display and pretty darn good camera".
"Mercedes-Benz---not as reliable as a Camry but drives great and carries a fair amount of status".
"Auto Zone---hey, if our counterpeople were rocket scientists, they'd be working for NASA, right? "
'11 GMC Sierra 1500; '98 Alfa 156 2.0TS; '08 Maser QP; '67 Coronet R/T; '13 Fiat 500c; '20 S90 T6; '22 MB Sprinter 2500 4x4 diesel; '97 Suzuki R Wagon; '96 Opel Astra; '11 Mini Cooper S
Then again it's not a stretch to figure out where he would eventually be without someone that can fix what he has right now. He would be buying a different one and that is what this is really all about. The people who are waiting for him to buy a new one don't want someone out there that can fix what he already has at any price.
http://www.cbc.ca/news/business/ford-f150-auto-parts-obsolete-go-public-1.3746577
And parts is parts.
Meanwhile Maybe his cluster will heal itself?
Seems like the "don't do it" advice often comes from people in the trade.
I suppose they will balk at the idea that this is part of the results of their efforts "to protect the consumers" but that doesn't change the perception from this side.
So is it $25/hour for the building and the lift? Can't charge for tools as construction workers have those too.
Tools/equipment not provided by the mechanic
Consumables (cleaners, etc.) not included in parts prices
Wages for the service advisors
Partial wages for cashiers, office manager, and other related staff
Office equipment & services (PCs, copiers, internet connection)
Customer lounge costs (land, TV/cable connection/WiFi, coffee, mag subscriptions)
Insurance
Overhead for write-offs/good will work
Marketing
Possibly loaner vehicles
I'm sure there's more.
Oh yeah, since these are small businesses without the accounting team that GE has, income tax is another expense.
I've never used a shop without a customer waiting area.
What I was feeling was a misfire which was being caused by the PCM shutting one of the injectors off, but I didn't know that for certain yet. But why was it misfiring? After stopping for fuel and restarting at idle the misfire that I suspected was obvious. Manipulating the throttle to change engine load and speed the misfire could be compensated for. One of the tricks that takes a long time to learn is how to use the throttle to change spark voltage demand to see if a misfire is spark leaking outside of the cylinder. To do that requires changing engine speeds and loads in a way that result in varying spark advance and cylinder air/fuel ratio's. While the misfire could be mitigated with engine speed and load, it did not respond to advanced spark timing and richer mixtures. Hmmm, worse than not good.
With the fuel stop and engine restart the system now did code and generate a MIL. I had to drive it attentively to respond to the few times that the PCM wanted to flash the MIL. There was no way this wasn't going to hurt the catalyst, the question was how much was it going to be damaged. I made it to the class location and grabbed a scan tool, P0302 and a P0300. During the break we did a fast ignition coil test (had spark), spark plug inspection and a quick swap between cylinders #2 and #3. The misfire remained with cylinder #2. That was the limit for what there was time for as well as the tools on hand but it was enough to know it wasn't going to be an easy fix.
After the class it was time to limp it home. A quick test by disconnecting the injector confirmed the vibration exactly as it felt at times noting prior to that, there were times that it didn't display the vibration with the injector connected. That confirmed that when the misfire was the worst it was either the PCM shutting the injector off or the circuit failing. If the PCM detects enough misfires it shuts the injector off to try to protect the catalyst. The rest of the trip home needed to be a balancing act between speed, load transmission gear range to mitigate the number of misfires that ultimately occurred. Getting it to the shop confirmed what I suspected especially since the initial discovery occurred with pulling a long hill. It lost compression in cylinder #2, burnt exhaust valve.
Oh well, not a big deal in my book because my Escape has a lifetime guarantee. If it breaks in my lifetime, you can guarantee that I'll be the person fixing it. These things aren't anyone's fault and all the care in the world can't prevent every possible failure, so it comes down to just deal with it. But I did grab one photo as I pulled it apart. Here are the cams and the top of the cylinder head.
I still might do the chain and guides while this is apart, but there is no scoring of the cam gear faces from the chain at all. There isn't even any play in the chain so it is completely serviceable if I want to leave it. That is really impressive when you start to put the numbers to all of this. I'm at 176K. At 180K the crankshaft will have turned on average about 4 billion times.The injectors and coils would each have fired about 2 billion times. The pistons have traveled some 8 billion strokes at 100mm per for a total distance of some 497,000 miles worth of sliding against the cylinder walls, each. To face a repair, and not a full rebuild is an amazing feat IMO and just goes to prove, they really don't build them like they used to.
LOL
Edmunds Price Checker
Edmunds Lease Calculator
Did you get a good deal? Be sure to come back and share!
Edmunds Moderator
So why didn't you just do a compression test right after you pulled codes and did the swaps between cyl 2 & 3? By then I suspect you knew what was up.
Why would the misfire go away on a certain type of downshift...is it that the increased revs generate just enough compression for the cylinder to fire? (I'd suspect about 80 psi would be required).
Edmunds Price Checker
Edmunds Lease Calculator
Did you get a good deal? Be sure to come back and share!
Edmunds Moderator
The PCM is able to detect misfires that the driver cannot because to the PCM a misfire is the failure of the crankshaft to accelerate sufficiently between 20 to 130 degrees rotation after TDC. That means the cylinder could fire and not necessarily slow the crankshaft, but not actually accelerate it inside of the window. When that happens the strategy is to shut the injector off to try and protect the catalyst, and that resorts in a full misfire that is easily felt.
At idle running compression is typically half of the cranking compression. In a class I often have the techs try and explain why that is. Any ideas? When tested my cranking compression was 44psi, the compression at idle was 65 psi. Normal cranking compression should be in the 190 psi range so my idle compression should have been between 85 and 100psi.