A Mechanic's Life - Tales From Under the Hood

thecardoc3 · July 2020

There can be a significant variance in system performance and the system can still pass the manufacturer's performance tests. Audi doesn't publish it's performance test in service information, it is built into the O.E. scan tool under the guided fault finding. A technician can attempt to test the system performance using a MACS (Mobile Air Conditioning Society) routine but with variable displacement compressors, sub-cooling liquid lines, H-valves, variable speed cooling fans and automatic controls in the interior it can be a real challenge.

xwesx · July 2020

So, what you're saying is that it is quite possible @andres3 just isn't cool enough to warrant forty degrees?

xwesx · July 2020

My son recently began a substantial project on the Econoline: Rewiring it! It's appearance horrifies me a little at the moment, but I am confident it will all come together.

guitarzan · August 2020

@thecardoc3 My friend is lamenting the swap of the intake filter in the Honda 1.5L turbo. He suspects the screws on the filter housing are cemented with Loctite. Is there a practical purpose for such?

thecardoc3 · August 2020

guitarzan said:
My friend is lamenting the swap of the intake filter in the Honda 1.5L turbo. He suspects the screws on the filter housing are cemented with Loctite. Is there a practical purpose for such?

There would be no reason to use loctite on the air cleaner screws. It's far more likely that corrosion is at play binding the screws in the captive nuts. I have many times had to cut the heads off of the screws to get the assembly apart, removed the captive nuts from the lower section to get to use heat in order to remove the screws from the nuts and then reinstall the nuts into the housing. That is a generic description of the routine and it has some variance depending on which air cleaner assembly a given vehicle has. I usually use a two inch cut off wheel to remove the tops of the screws. You have to take a little time with that and keep cooling the screw or you risk melting the plastic. There are a lot of air cleaners that got new screws and nuts installed.

guitarzan · August 2020

Thanks Doc!

thecardoc3 · August 2020

You're welcome. This is easier to do than it sounds. I do this so quick you wouldn't even know it presented as a problem.

guitarzan · August 2020

In this case he was swapping the filter after 2 years and it was sticky but the screws came out. He plans to do an annual filter change and this was a "long" interval for him. I also suggested that he grease the screws.

guitarzan · August 2020

We have two newer Subarus now, my Outback and the wife's Impreza. The engines clack like heck. Should I change the oil to 30 weight from the 20 weight? Everything that I have read says the 20 weight causes excessive noise, but I have not dove in yet so I have no empirical evidence. It could be the character of these boxers for all that I know.

@thecardoc3 was a single engineering change made to go to this 20 weight oil, do you know from observation? Is this oils excessively thin? Are techs dealing with unforeseen problems from it? Speaking from a perspective that many believe that the change was completely arbitrary to boost fuel efficiency by an immeasurable amount.

thecardoc3 · August 2020

At operating temperature there is very little difference between a 30 grade and a 20 grade base stock oil. At cold temperatures a synthetic will likely be "thinner" than a conventional oil, that's a characteristic called the Viscosity Index. The higher the viscosity index (VI) number the less change there is in the actual viscosity over a 100 degree C range. It's very important for the oil to flow quickly when cold and the high VI allows for that. What kind of a noise are you hearing? A valve tap? A rod or main bearing that quiets up in a few seconds after start-up or a piston slap that is noticeable until the engine gets close to or reaches operating temperature?

thecardoc3 · August 2020

Here is a chart that shows the SAE viscosity in Cts at 100C and 150C. You'll notice that at 100C a 30W is 9.3 to 12.5 Cts and drops to 2.9 Cts by 150C. A 20W at 100C is 6.9 Cts to 9.3 Cts and drops to 2.6 at 150C. So at full temperature they are only .3Cts different.
http://www.lube-media.com/wp-content/uploads/Viscosity-matters-WEB-ONLY-Sept19c_FINAL.pdf

xwesx · August 2020

I know that many folks do have clatter from their boxer engines. I have had six of them, and never clatter from any of them, including my '96 Outback that had 220,000 miles on it by the end. Our newest one, with the "FB" engine block, does have a noisy few seconds upon startup, but it quiets right down to "normal" as the engine settles into idle.

They are very sensitive to low oil conditions in terms of valvetrain noise. Anything approaching a quart low will induce it.

guitarzan · August 2020

@xwesx What oil viscosity have you used in all of your vehicles? Was 20 weight used in any of them?

@thecardoc3 All good questions and I do not have specific answers. All I know is that in an era where engines have generally gotten quieter, these engines sound "loud" to me. These are also my first Subarus. I found this in a forum which seems applicable: "Subaru's tend to have loud clackety motors when listened to from outside the car. The valves of an H4 motor are essentially at the bottom of the car and that valvetrain noise bounces off the pavement and out from under the car. Whereas in a typical inline 4 motor, the valves are between the block and hood and that noise gets dispersed around the engine compartment and never really makes it out."

That 540 Rat still talks about following the rule of 10 psi per 1,000 rpm, and apparently the 20 weight being at the low range of the 30 weight does not maintain that. Is there any validity to that rule today as machining accuracy has increased significantly in these last couple of decades?

I am surprised when you talk of fully-warmed up being 300F. Many current oil spec sheets show a peak temp of 290F, and one would not want to be at the peak of any engineering limit as the oil becomes sacrificial then does it not? From your comments it sounds like oil performance is keeping up anyway.

kyfdx · August 2020

@guitarzan I thought my Subaru engine was noisy, as well ('08 Impreza)

xwesx · August 2020

@guitarzan I used 5w30 conventional in my '96 outback. The 2007 and 2008 Outbacks, as well as the 2008 and 2010 Foresters, used 0w-30 full synthetic. All of these cars used the EJ25 block; the '96 was DOHC, while the rest use the SOHC (all naturally aspirated).

The 2013 Forester has the newer FB25 block, and that one requires 0w-20 oil. This is the one that will clatter for a second or two upon startup before it quickly quiets down. When I was having the oil consumption issue (short block replaced under class-action settlement) a couple years ago, I asked about the possibility of the oil simply being 'too thin' for the engine tolerances (I was thinking the piston rings), which was allowing it to drink about a quart of oil in less than a thousand miles (varied depending on how hard the engine was working). The service guys said that the heavier oil wouldn't solve the consumption problem and could possibly cause oil starvation in the cams due to tighter tolerances and smaller passages. I don't know if they knew this or were just making it up.

I haven't had any issues with consumption since the block replacement; I think I might have around 30,000 miles on the engine since then. However, the tech didn't do a great job sealing it up, and I have two points of external leakage on the front of the engine now. I haven't identified them, but I suspect at least one is a camshaft seal. I'm hoping both are up in the heads, as those aren't tough to fix with *relatively* minor surgery.

All that being said, the engine is naturally louder than inline four-cylinder engines, in general. I wouldn't call them noisy, but certainly more audible.

roadburner · August 2020

The "lean condition" in the Mini was caused by the O2 sensor- but not for the reason you'd think- it was due to misrouting the sensor harness/connector. It was routed close to the oil filter housing- exactly where oil would drip when the filter element was removed. The vehicle harness/connector was cleaned up, the harnesses were correctly routed and a new sensor was installed. There were a couple of other issues traced to shoddy work- and based on the service history I'm virtually certain that it was the same shop I mentioned before that had changed hands and threw parts at my friend's Cayman S for three in a futile attempt to fix a cooling system issue.

thecardoc3 · August 2020

xwesx said:
The service guys said that the heavier oil wouldn't solve the consumption problem and could possibly cause oil starvation in the cams due to tighter tolerances and smaller passages. I don't know if they knew this or were just making it up.

Camshaft journal clearance spec is 0.0015" to 0.0028".
Connecting Rod Clearance spec is 0.0007" to 0.0015" ( that's not a misprint, 7 / 10,000's of an inch)
Main Bearings Clearance sec is 0.0004" to 0.0012" The mains are even tighter.

Starvation and bearing failure from oil that is too thick to flow is a common failure.

xwesx · August 2020

thecardoc3 said:

xwesx said:
The service guys said that the heavier oil wouldn't solve the consumption problem and could possibly cause oil starvation in the cams due to tighter tolerances and smaller passages. I don't know if they knew this or were just making it up.
Camshaft journal clearance spec is 0.0015" to 0.0028".
Connecting Rod Clearance spec is 0.0007" to 0.0015" ( that's not a misprint, 7 / 10,000's of an inch)
Main Bearings Clearance sec is 0.0004" to 0.0012" The mains are even tighter.

Starvation and bearing failure from oil that is too thick to flow is a common failure.

Those are some incredibly small tolerances. So, the takeaway here is that, yes, 20-weight versus 30-weight can make a difference with tolerances this tight?

thecardoc3 · August 2020

xwesx said:

Those are some incredibly small tolerances. So, the takeaway here is that, yes, 20-weight versus 30-weight can make a difference with tolerances this tight?

If there is going to be an issue it will be likely to occur cold when the "W" side of the rating is more important. Hydrodynamic lubrication is the primary protection from wear that the oil is responsible for providing. It's comparable to hydroplaning. Given enough speed and depth water can separate the tires from the road. The oil does the same thing but is squeezed out from inbetween the bearing and the crankshaft. As long as new oil can flow into the bearing to replace what was squeezed out it will maintain the necessary lubrication.

thecardoc3 · September 2020

This hasn't been visited in a while. Predictably it still is going to get a lot worse before it starts to get better.
https://www.sun-sentinel.com/business/fl-ne-auto-tech-shortage-nationwide-who-will-fix-our-cars-20190809-bm77cet2jfgqdcpe2rekebll6u-story.html

guitarzan · September 2020

“Then there were those who stared at the car like it was some alien technology.”

On one hand LOL, on the other hand it is the teacher's job to take the unfamiliar and make it familiar, take the talentless, and inspire them with confidence. There are definitely some terrible problems with educational methods in the USA. The kids who could not read in the 5th grade? They still could not read in the 12th grade. Whose fault is that? They were labelled on day one, put in the "dumb" reading group, and that effect snowballed in their psyche, sometimes throughout the rest of their life! So when this article labels the newbies as "there for the money", well, who is not there for the money? I enjoy my job, but, I am there for the money. You guys? Cars are the perfect example of "break it down into its components and it becomes understandable."

"A lot of students just don’t have his drive"

This is a big problem with young people today in general. I know business owners that cannot get employees to show up for work, they cannot find replacements, their selection of young people is just downright awful. A fortune communications company employee told me the company cannot identify tech candidates who can pass the drug test. This is a role where they have internal training, take someone who is ignorant, and fully train them for the job.

I know there are always lazy people in a civilization but it is truly bad now. Yes, a job like working on cars that is similar to 8 hours of going to the gym? I can see that today, finding people to do it is nearly an impossible task.

thecardoc3 · October 2020

Here is a nice example of using some of the advanced tooling that is available to shops today. Rob came to my shop a couple weeks back for some hands on training with this tool and has been gaining experience with it since then.

https://www.youtube.com/watch?v=eTHxzQtTaOs&feature=youtu.be&fbclid=IwAR2_zaN0E-aGv34YjHqkhjN4fiHpS4RXdcYgzeYr3dvECN-SS1fKhza9myM

thecardoc3 · October 2020

Here was Rob's video from the time that he spent with me.

https://www.youtube.com/watch?v=riXKd76vwXU&t=620s

guitarzan · October 2020

Quite odd that a shop installed a dry differential. Wow.

The troubleshooting with the computer, the extent to which devices are used today, that boggles the mind.

thecardoc3 · October 2020

guitarzan said:
The troubleshooting with the computer, the extent to which devices are used today, that boggles the mind.

These accelerometers are some of the newest toys for us. There was quite a bit of studying that had to be done both hands on, and class preparation to get ready to present this to the technicians.

The second video was from the most time that I have gotten to spend with the tool while helping Rob learn how to interpret the data that was going to be generated. For guys like me we had to learn how to figure out vibrations and their causes (source) totally on our own. After forty plus years of fixing vibrations in cars, just by feel alone, I have gotten to be pretty good at it. But the path to get "here" was a mixed bag of successes and failures. Now with tooling like this to assist the technicians, once the vibration is confirmed to be related to a given component, or system hopefully they won't have to have as many hard days at the job honing their skills.

There is a lot to learn with this tool. The first thing is any vibration over 10mg (milli-gravity) is strong enough to be felt. Watch either of the videos closely for the "Ts". T1 is a single tire vibration. T2 is a vibration happening at twice the frequency if a T1, and a T3 is of course three times the frequency of the T1. Consider that the driveshaft will be spinning somewhere between two and three times the wheel speeds. Watch how the T2 and T3 are sometimes low and T1 is very high, then you will see the T1 dropping as the T2 and T3 increase and decrease in amplitude. That is three tires with vibrations, that are usually out of phase with each other but on occasion get into phase. That is something that can make just using a learned feel very tricky. The advantage of the tool is once you see a P1, that is a driveshaft vibration due to runout or imbalance and now you shouldn't be distracted by the tires.

Here is a capture from the first video showing the P1 very clearly.

guitarzan · October 2020

Based on the input from the vehicle these devices should get to the point where they are just a GUI. You should no longer have to look at a generated signal. It should tell the tech in plain text that "X is wrong."

thecardoc3 · October 2020

guitarzan said:
Based on the input from the vehicle these devices should get to the point where they are just a GUI. You should no longer have to look at a generated signal. It should tell the tech in plain text that "X is wrong."

On one hand that would be great. On the other this tool will take the technician's learned experience side of the equation and nullify it. Then some day along comes a car and the tool get's it wrong. Remember the tool can only be as good as the person that wrote the program. Now someone will have a car that has a problem that the technician hasn't learned how to figure out on their own and the tool can't help either.

guitarzan · October 2020

There is another shop closing. This is a family motorcycle repair business that has been around for 30+ years. They repair any bike which is unusual in these times. These folks like most small business owners never charged enough and they always always helped their community. On their business time they taught those in poverty to learn to repair their own bikes. They contributed in every way possible.

They were doing alright but the landlord does not want that type of business and is forcing them out. They can not afford rent anywhere else in the growing town.

They are selling off a half century collection of parts for pennies on the ten dollar. Some of it like wheels will get melted down rather than get into the hands of people restoring old bikes who would otherwise see the parts as gold.

The owner is around 60.

Meanwhile those who are good customers continue in vain to find anyone competent enough to touch their bike.

thecardoc3 · October 2020

It will get worse before it get's better, "IF" it ever does. Lately the requests for me to take on older vehicles has started increasing. They are almost always "resurrections" where the vehicle hasn't run for years and in many cases has been hacked up either before or after it was parked. It takes a different kind of patience to work through these and I nearly have a 1978 F150 ready to go. I have a '58 Ford showing up as soon as the truck is down the road. That one will be really interesting as it hasn't run for more than twenty years (estimate).

thecardoc3 · December 2020

Ads like this one which was posted in a technicians group show just how bad the tech shortage has gotten. Several technicians did respond back in the forum, and one of them asked very directly about the conditions that have to be achieved in order to claim that bonus. There are very likely strings attached, and the "Up To" leaves a lot of room for the dealer to make it unlikely that the $20,000 will be paid out. https://lithia.wd5.myworkdayjobs.com/en-US/LithiaCareers/job/Baierl-Subaru-of-Pittsburgh-Pittsburgh-PA-15237/Automotive-Technician----20k-SIGN-ON-_R6305?fbclid=IwAR3hzJ1kSXjCtPCxcjFf9SNQKTZ77BhMReyqdiH5lCVsw2qrkoQiVSDXoBw

guitarzan · December 2020

"Prior automotive repair experience preferred"

Ummm...am I eligible? (I have no experience at all.)

andres3 · December 2020

Doug DeMuro just bought a '94 Audi RS2 he had to import to get into the USA. He made a video where he stated the ultimate Audi/VW only shop in town (San Diego) apparently said "no thank you, 2004 and newer only please).

I suppose if your shop is busy enough, no need to entertain one-off projects like a 25 year old Audi Wagon with Porsche touches.

thecardoc3 · December 2020

guitarzan said:
"Prior automotive repair experience preferred"

Ummm...am I eligible? (I have no experience at all.)

Techs that are qualified, experienced look at the add and can't help but be skeptical about it. One of the best responses from one of the techs was "If you have that kind of money available, why don't you give it to the techs you already have and maybe be able to keep them instead of needing to look for new techs here?" (paraphrased)
The poster didn't respond to that question.......

thecardoc3 · December 2020

andres3 said:
2004 and newer only please.

I suppose if your shop is busy enough, no need to entertain one-off projects like a 25 year old Audi Wagon with Porsche touches.

That can be attributed to a flaw in the system. "Flat Rate" even for the aftermarket relies on first hand experience with the models being serviced. As similar as this vehicle may be in some ways to the cars they usually work on there are many differences which the techs would have to take time and study about in order to be proficient with this one car. To make time the techs often need two or three repair events to be truly familiar with a given car and thus then be able to be close to the quoted times when actually doing repairs. A one time event is a loser, and can take two to three times to perform a given repair than what they would quote the repair by the manual so it just doesn't make sense to do it when they would be much more efficient (profitable) limiting the models that they service.

thecardoc3 · December 2020

Here is one that I helped a shop with last week. I went into this expecting to get to really show some advanced routines (which is why I wanted to video it) only to come up with the answer in less time than the video lasts. It goes that way sometimes. There are diagnostics that can take a lot of physical work just to access the location of the failure and there are others that don't. This one didn't take much physical effort nor time, but it reminds me of what techs often go through. I can't tell you how many times I heard "that was so easy we can't charge the customer for figuring that out". The reality is that it was only easy AFTER the answer was known which took a lot of time and effort, and investment to learn how to do.

https://www.youtube.com/watch?v=eTMhw_kAhvA&t=1s

guitarzan · December 2020

How much current can the headlight absorb? One has to know numbers before trying this (obviously you do). If the fuse is even a minimal one of 10A my thought is that the circuit is still at risk of excessive current (?)

You mention that trailer harnesses are suspect. I guess the install does not match the expense of that Cadillac. I would expect an installer to use better judgement and incorporate strain relief and vibration protection. That is an egregious install job.

thecardoc3 · December 2020

Different lams do have different current draws. When first turned on that round headlight spikes around 12-14 amps but that only lasts for .010 seconds (ten milliseconds) which is too fast to blow the fuse or stress the module. Then the current drops to 6 amps while the lamp was lit, well within the circuit tolerance. This same routine can be used with lower current levels by choosing an appropriate lamp such as a turn signal bulb (1.25 amps) or even a side marker (.3 amps).

roadburner · January 2021

I just took my wife’s X1 to my dealer for an oil service. The tech working on the car filmed a brief video showing the condition of the tires and brake pads as well as showing that there were no leaks under the vehicle. No upselling at all. That said,I’m seriously tempted by the new Supra, which shares the platform, mechanicals, and telematics with the G29 Z4, but potential servicing pitfalls are keeping me from pulling the trigger. I’m thinking that most Toyota dealers will not be inclined to put a lot of effort into training techs to service a car that only sells in very limited numbers. I don’t blame them- from an economic standpoint it doesn’t make sense as nationwide Toyota has yet to move 9,000 Supras over the curb, but that situation gives me pause.

thecardoc3 · January 2021

"Digital Vehicle Inspections" are a nice change to the service routines and really improve communication at every level. As far as servicing limited vehicles go the GMC Sierra Hybrid that I just repaired, for a dealership, is a great example of what can happen when there just isn't enough of a given model running around for the technicians to be fully trained and truly experienced with them.

roadburner · January 2021

thecardoc3 said:
"Digital Vehicle Inspections" are a nice change to the service routines and really improve communication at every level. As far as servicing limited vehicles go the GMC Sierra Hybrid that I just repaired, for a dealership, is a great example of what can happen when there just isn't enough of a given model running around for the technicians to be fully trained and truly experienced with them.

I liked the digital report; the tech reported both the tread depth and pad thickness in millimeters. As for the Toyota servicing issue, it's frustrating. Again, I don't blame the dealer from an economic standpoint, but there are going to definitely be some bumps in the road. The internet almost always amplifies issues with a certain vehicle, but I've read more than one report of Toyota dealers not using the correct Toyota "GR" oil that has BMW Longlife approval.

thecardoc3 · January 2021

We really have to do our homework when it comes to keeping up with the oil standards. Yes this is a BMW LL oil, but it's BMW LL-17FE+ which means it's not a High HTHS like BMW LL-01 (ACEA A3-B4) it's a Low HTHS with is along the lines of the North American specifications. https://www.marketscreener.com/news/latest/Valvoline-Launches-NEW-SynPower-MST-C5-Motor-Oil-SAE-0W-20-in-Europe--27771460/

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwj60NS3hKfuAhVDp1kKHfoFC7IQFjAOegQIIBAC&url=https://www.mobil.com/lubricants/-/media/project/wep/mobil/mobil-row-us-1/files/faqs/mobil-1-oil-product-specs-guide.pdf?la=en&hash=B478EACF4BAC5D7B9A3D33763B53E67669592EE5&usg=AOvVaw24DfL4w38u7I09QLpAYaJB

roadburner · January 2021

Yes- 0W-20.

guitarzan · January 2021

thecardoc3 said:
We really have to do our homework when it comes to keeping up with the oil standards. Yes this is a BMW LL oil, but it's BMW LL-17FE+ which means it's not a High HTHS like BMW LL-01 (ACEA A3-B4) it's a Low HTHS with is along the lines of the North American specifications...

It is sad that the EPA and EU are driving an excessively complex and expensive motor oil catalog. This is oil. That flows between parts. Really?

roadburner · January 2021

guitarzan said:

thecardoc3 said:
We really have to do our homework when it comes to keeping up with the oil standards. Yes this is a BMW LL oil, but it's BMW LL-17FE+ which means it's not a High HTHS like BMW LL-01 (ACEA A3-B4) it's a Low HTHS with is along the lines of the North American specifications...
It is sad that the EPA and EU are driving an excessively complex and expensive motor oil catalog. This is oil. That flows between parts. Really?

As long as you stick with one brand it's not too bad.

thecardoc3 · January 2021

When we present the engine oils training class we stress looking for O.E. approvals over brands. It's the same thing we dealt with back when GM's dexos became their specification. We expect to see products that will carry both the BMW LL17 and GM's dexos1 Gen2 approvals. The only thing I'd like to see on top of those is the ACEA A5/B5 with that C5.

imidazol97 · January 2021

thecardoc3 said:
When we present the engine oils training class we stress looking for O.E. approvals over brands. It's the same thing we dealt with back when GM's dexos became their specification. We expect to see products that will carry both the BMW LL17 and GM's dexos1 Gen2 approvals. The only thing I'd like to see on top of those is the ACEA A5/B5 with that C5.

I see the Pennzoil Euro L full synthetic oil in 5W-30 with Dexos2 ratings. It says it's API SN and all previous categories, ACEA C3 and GM dexos2.

A general label on the back of the bottle says "For diesel and gasoline engines."

This caught my attention because it was Dexos2 rather than Dexos1, therefore many
would assume it's a better Dexos rating for the oil.

Is this suitable for use in a Chevy Cobalt 2.2 engine?

thecardoc3 · January 2021

imidazol97 said:
I see the Pennzoil Euro L full synthetic oil in 5W-30 with Dexos2 ratings. It says it's API SN and all previous categories, ACEA C3 and GM dexos2.

Dexos2 is a high HTHS oil along the lines of the older BMW LL-01

ACEA ratings take some studying, they aren't linear. A1/B1 is a low HTHS product the same as a A5/B5. The difference is the A5/B5 is truly a long life version. While Dexos1 is an extended life specification it doesn't need to meet A5/B5 requirements. A brand can make a product that will meet both specifications if they wanted to, but that would of course be reflected in the price of the product.

imidazol97 said:

A general label on the back of the bottle says "For diesel and gasoline engines."

This caught my attention because it was Dexos2 rather than Dexos1, therefore many
would assume it's a better Dexos rating for the oil.

Is this suitable for use in a Chevy Cobalt 2.2 engine?

No, it would not. Being Dexos2 doesn't make it a better or worse product when comparing it to a product approved for Dexos1 Gen2. They both advanced products and would be an excellent choice for a vehicle requiring those specifications (dexos1 for a dexos1 requirement and dexos2 for a dexos2 requirement) while being a poor choice for a vehicle requiring the other specification..

roadburner · January 2021

thecardoc3 said:
When we present the engine oils training class we stress looking for O.E. approvals over brands. It's the same thing we dealt with back when GM's dexos became their specification. We expect to see products that will carry both the BMW LL17 and GM's dexos1 Gen2 approvals. The only thing I'd like to see on top of those is the ACEA A5/B5 with that C5.

I agree; I wasn't clear- I meant brand of vehicle.

guitarzan · April 2021

I created a topic regarding vehicles that are not being used since COVID policies have stopped a lot of commuting and shopping. My thread received zero replies. But I am curious, will there be a flood of vehicles that will have problems with old gasoline? Do modern designs inhibit issues more than ever or is the modern vehicle more sensitive to this?

When a vehicle shuts off vacuum is created, drawing all vapor from the tank yes? So there would be little O2 to assist in oxidation of the fuel?

I know winter is helpful as all chemical degradation slows down with lower temperatures. Except for those of you who have nice weather all year long.

I think I used Seafoam in my last Outback fill-up but I cannot quite recall. That gas is likely two to three months old.

xwesx · April 2021

I imagine there would have to be some level of implication with the ethanol-laced fuels. Gasoline that does not have that additive doesn't seem to mind a year or two (or three) of sitting between fill ups. Newer cars are definitely going to take issue with sparse use if they don't get started at all for weeks at a time, because all their passive electronics do pull some current and will weaken/drain the battery without assistance.

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