Car stalls during idle after battery replacement, then fine after two days

[Averagesupernova]

Any theoretical efficiency improvement from a manual can be more than compensated for by shifting through an inhuman number of gears at inhuman speeds.

Lol. True. So is a ten speed transmission shifting through 'inhuman number of gears'? It's the most I've seen in light trucks/pickups. So far, I like the one I drive. Even semi tractors can have as few as 9 speeds. Never thought I'd see ten speeds in pickups but here they are.

 

[Baluncore]

It either regulates rpm based on throttle position or it doesn't.

In the USA it is comm to call it throttle even though it is not restricting the intake.

Maybe you were referring to the accelerator pedal, and the linkage to the injection pump?

 

[Averagesupernova]

Maybe you were referring to the accelerator pedal, and the linkage to the injection pump?

Naturally.

 

[Baluncore]

So is a ten speed transmission shifting through 'inhuman number of gears'? It's the most I've seen in light trucks/pickups.

A ten speed transmission would now be a dual clutch automatic transmission, without a torque converter. It would have 5 gears on the main shaft, with an odd and an even countershaft.

A CVT is really only applicable to light-weight cars, when the inefficiency of the torque converter needs to be eliminated from the automatic transmission.

 

[Averagesupernova]

A ten speed transmission would now be a dual clutch automatic transmission, without a torque converter. It would have 5 gears on the main shaft, with an odd and an even countershaft.

I'm curious as to which transmission you refer to. The 10 speed I have in a Ford pickup has a torque converter.

 

[Baluncore]

I'm curious as to which transmission you refer to.

One without a torque converter.
https://en.wikipedia.org/wiki/Dual-clutch_transmission

If you have a Ford 10R80 transmission, then you have my sympathy.
"In summary, Ford 10-speed automatic transmission vehicles face continuing issues with harsh shifting, hesitation, acceleration problems, and potential safety hazards based on thousands of complaints. Multiple lawsuits allege Ford concealed innate defects while failing to issue adequate fixes over the past five years. 8 Mar 2024"

 

[Averagesupernova]

One without a torque converter.
https://en.wikipedia.org/wiki/Dual-clutch_transmission

If you have a Ford 10R80 transmission, then you have my sympathy.
"In summary, Ford 10-speed automatic transmission vehicles face continuing issues with harsh shifting, hesitation, acceleration problems, and potential safety hazards based on thousands of complaints. Multiple lawsuits allege Ford concealed innate defects while failing to issue adequate fixes over the past five years. 8 Mar 2024"

We'll see. So far I am happy with it. I have also seen about the troubles with the 10R80. To contrast that, I have a 2001 Dodge 1500 pickup that the transmission failed at less than 60,000 miles. Total junk. That transmission had an easy life prior to the failure. By the time any problem was noticed the convertor had released enough filings into the system that a complete disassemble cleaning and overhaul was necessary.

 

[Baluncore]

Torque converters are inefficient, so they cost more for fuel and release more emissions. They need to be replaced, probably with dual clutch transmissions.

Disassembling automatic transmissions with problems is too complex and expensive. Give me a manual transmission, I can fix that.

 

[Averagesupernova]

Some form of automatic transmission will be the norm. A person can't even find drivers for semi trucks that want to drive a manual. I agree a manual transmission is easier to work on but people like you and I who tackle such things generally are in the minority. How long it takes before the torque converter as we know it is replaced I don't know. Based on the link you provided I can see how it could function as an automatic but not in the same way an automatic would with a torque converter.

 

[Baluncore]

How long it takes before the torque converter as we know it is replaced I don't know.

When simple automatic transmissions with two or three ratios were common, a wide-range torque converter was needed to interpolate between those ratios, and to extrapolate beyond the highest and lowest ratios. That was important with the narrow RPM power-band of a petrol engine. Having many available gear ratios reduces the need for a wide-range torque converter.

A diesel has flat torque across the band, so power is proportional to RPM. If RPM ever falls too far, power and momentum are lost. Having many ratios available is an advantage when operating in the narrow band near the top of the diesel RPM range.
Eaton produced the 18 speed Road Ranger crash gearboxes, used in trucks to optimise power output, over a wide range of road speeds.

When the torque converter retires, many gear ratios will be needed in the gearbox.

 

[jack action]

Torque converters are inefficient, so they cost more for fuel and release more emissions. They need to be replaced, probably with dual clutch transmissions.

Do you have sources for that? It seems that automakers are renewing with torque converters:

Modern Cars With Torque Converters

• In 2018, Audi Launched the 2019 RS5 Sportback equipped with a conventional eight-speed automatic with a torque converter instead of a dual-clutch transmission. The 2019 Audi RS5 Sportback is propelled by a twin-turbocharged 2.9-liter V6 outputting 444 horsepower and 443 pound-feet of torque. Its project manager Anthony Garvis stated that the car is a grand tourer and conventional transmissions are just as fast as dual-clutch units while ditching the herky-jerky low-speed behavior
• In 2021 BMW launched the M3 Competition which was equipped with an eight-speed regular torque-converter automatic, rather than a dual-clutch (DCT) unit, driving via an electronically controlled limited-slip differential. This sparked the debate if the torque converters are back coming back in the performance cars.

The new M3 is being offered in the UK armed with the ZF 8HP torque-converter automatic, which is now in its third generation and has been steadily developed since its introduction in 2009. Strip away all the internal mechanical differences and the key distinction between it (or any torque-converter-based transmission) and a DCT or manual is that the torque is transmitted from the engine to the gearsets by a fluid coupling, the torque converter, rather than by a clutch or clutches

Similarly, Mercedes-AMG C63 S, Porsche 911 Carrera S, and Jaguar F-Type R have also adopted the torque converter transmission and this shows that many of the disadvantages and issues of the torque converters have been tackled with and will see a rise in the adoption.

“So at first, considering the power and performance from a standing start, the torque converter is working very well. And also the serious driving around the road, with speed conditions, torque converter is also doing a very good job,” GR Corolla Chief Engineer Naoyuki Sakamoto told The Drive.

“Then after rolling out, lockup engaged—so after that, the torque converter doesn’t slip. So in that case, there’s no difference between the DCT and automatic transmission. Both [transmissions are] shifter-changing, releasing the clutch and grabbing the clutch, so they’re almost the same. So as a result, we’re choosing the automatic transmission. We don’t have to use a dual-clutch transmission.”

It seems that, at least according to Toyota, there wasn’t much of a performance gain to be had by switching to a more complex and more expensive DCT. Toyota knows that DCTs have their advantages, but they apparently aren’t attractive enough to warrant the switch.

“Of course, there are pros and cons. Sometimes a DCT is better, sometimes AT is better. That’s true. But we have a long history of improving the automatic transmission,” Sakamoto said. “We want to take advantage of our capability, so that’s why we’re focusing on the automatic transmission. We understand a DCT is better in some ways, like weight, but still, we’ve been able to improve the technology of the automatic transmission through motorsports.”

For the foreseeable future, all self-shifting transmission for the M Division will be traditional torque-converter automatics of some kind; be it the current ZF eight-speed or an updated unit. While there are whispers about the decision being made over torque, with some rumors that modern DCTs can’t handle the torque of new M cars, they’re nonsense. The real reason is that the ZF eight-speed is more efficient and easier to calibrate for ultimate efficiency. And because efficiency is more important than almost all else in today’s automotive climate, the DCT is a casualty of the times.

“I'm not even sure the next generation of M3 and M4 models from BMW will have the option of a manual gearbox,” [BMW M’s vice president of sales and marketing Peter] Quintus stated.

“[And] we are now seeing automatic transmissions with nine and even 10 speeds, so there's a lot of technology in modern automatics.

“It's more a question of how long has the DCT got to go. How long will it last?”

Quintus told Drive that modern automatics have largely closed the technology gap to the DCT, while increasing outputs for M’s performance cars meant manuals struggled to cope with beyond 335kW and 600Nm.

It could be one reason why the just-released BMW M4 CS ramps up the boosted 3.0-litre six-cylinder from 550Nm to 600Nm, but is DCT-only.

The vice president of sales and marketing continued: “The DCT once had two advantages: it was light and its shift speeds were higher. Now, a lot of that shift-time advantage has disappeared as automatics get better and smarter.”

The 8HP is a prime example of the modern super-efficient automatic transmission. Internally, the flow of cooling oil can be increased or reduced as needed to save the amount of energy consumed by the cooling pump. The pump supplying pressure for the gearshift actuation system is electrically driven to keep it working while the engine is shut down for longer start/stop and coasting periods.

Most importantly, the minute control over ‘shift point optimisation’ to maximise fuel consumption that it gives engineers is so good that it’s very hard to better it. The 8HP can handle up to 738lb ft ‘input’ torque from the engine, easily accommodating the M3’s 479lb ft. It weighs 87kg – relatively light but still roughly double that of a six-speed manual.

Like it or lump it, though, the choice of automatic transmission technology has gone full circle, from torque converter through AMTs and DCTs and back to torque converter, and that’s unlikely to change now.

Q: Can a torque converter offer the same fuel efficiency as a clutch?

A: Modern torque converters have improved significantly in efficiency and can closely match manual transmissions, especially when paired with advanced automatic transmission technologies.

Automatic and manual transmission myths debunked

While the differences between manual and automatic gearboxes are well-documented, there remain some common beliefs about both that have either become less relevant with evolving technologies or were never accurate in the first place.

[...]

It is often said that manual transmission is more fuel-efficient, and that was indeed once the case. Still, with the introduction of electronically-assisted systems, including DCT, the lines are becoming blurry between manual and automatic transmissions' performance. [...]

 

[Baluncore]

Do you have sources for that?

A mechanical clutch only gets hot when it slips under load. While operating, fluid couplings get hot and so need oil coolers. QED.

Oil coolers fail, often mixing transmission fluid with engine coolant, in an expensive demon-stration of built-in redundancy.

Motor vehicle design is based largely on feel and perception, not on optimum fuel efficiency. Hiding gear changes behind constant acceleration is often unnecessary, and has become an expensive pursuit of impossible perfection.

Design problems, with smooth DCT gear changing under load, may require a torque converter to absorb the transients. The torque converter can then be locked mechanically, so it ceases to be a torque converter, giving the efficiency of a mechanical drive.

Where traffic lights cause start-stop flow, and there is an aversion to roundabouts, there will be a natural selection for automatic transmissions. That is expensive and inefficient.

 

[Ranger Mike]

Yes a torque converter is slower and cost more to manufacture than a manual transmission set up but you miss one giant point. In the late 50s earl y60s the manual trans was the most common. Today it is rare. Why? Women demanded the automatic transmission. Since they are now over 51% of the population, guess who the auto makers are targeting too? Climate change ( transmssion heat) and fuel milage go out the window when it comes to ease of operation and comfort.

 

[jack action]

Today it is rare.

A manual transmission is really fun when you are alone on a long winding road. But today I seem to be more and more stuck in bumper-to-bumper traffic jams where the use of the clutch is just a pain. For an everyday car, I will choose an automatic transmission every time.

 

[JT Smith]

A manual transmission is really fun when you are alone on a long winding road. But today I seem to be more and more stuck in bumper-to-bumper traffic jams where the use of the clutch is just a pain. For an everyday car, I will choose an automatic transmission every time.

I think that overstates it a bit. Even in the city with stoplights a manual can be fun as long as there isn't gridlock. But in bumper to bumper, stop and go traffic even die hard manual enthusiasts have to admit that an automatic is better.

It's getting to be where it's a moot point. Each year there are fewer models available with a manual transmission.

 

[Ranger Mike]

A manual transmission is really fun when you are alone on a long winding road. But today I seem to be more and more stuck in bumper-to-bumper traffic jams where the use of the clutch is just a pain. For an everyday car, I will choose an automatic transmission every time.

Whole heartedly agree..but I am no spring chicken! Towing a race car trailed with Dodge diesel truck and 6 speed manual trans is a bear! Loved it in my younger days!

 

[Baluncore]

But in bumper to bumper, stop and go traffic even die hard manual enthusiasts have to admit that an automatic is better.

That is really a statement about poor traffic engineering, and the lack of good public transport.

I was given an automatic with cruise control. They seem to be at war with each other, at my expense, a marriage arranged by Ford-Mazda. Maintaining the exact legal speed limit is all I ask, but that monster, in our gentle hill country, is forever varying speed by enough to annoy the following traffic, or cost me my licence.
Still, it was free, has air conditioning and a good stereo, so damn the environment.

 

[russ_watters]

I was given an automatic with cruise control. They seem to be at war with each other, at my expense, a marriage arranged by Ford-Mazda. Maintaining the exact legal speed limit is all I ask, but that monster, in our gentle hill country, is forever varying speed by enough to annoy the following traffic, or cost me my licence.

I've never had that happen and it makes no sense. Are you complaining about the car's shifting choices? If you were in a manual going up a hill in cruise control it wouldn't be able to shift and you'd lose speed.

This is a weird argument.

 

[Baluncore]

I've never had that happen and it makes no sense. Are you complaining about the car's shifting choices? If you were in a manual going up a hill in cruise control it wouldn't be able to shift and you'd lose speed.

No, the shifting is at the right time. The problem seems to be with the slip-ratio in the torque converter, that introduces a hysteresis into the control loop. The response time of the loop, is similar to one quarter of the hill wavelength, the hills being more like an ocean swell than a series of ranges.

The overdrive gear allows it to overspeed downhill, so I find myself locking out the overdrive when descending hills, and using the accelerator to help it climb hills. Cruise control makes me subordinate to the vehicle.

I probably view and analyse it differently, because I normally drive heavy diesels with manual transmissions. They have a wide torque range, so gear changes are not needed.

 

[Averagesupernova]

@Baluncore did you bother to investigate a potential defect with the cruise control or would you rather have complained about it? I haven't driven anything ever with a cruise control that was as bad as you say. If it truly was that bad I'd have looked for something wrong. Possibly a vacuum leak in the actuator.

 

[Baluncore]

... did you bother to investigate a potential defect with the cruise control or would you rather have complained about it?

It works well on the flat or on highways, and throws no warning codes. I think it is the road profile that upsets it. Until now, I have driven a few petrol-engined cars with manual boxes and cruise control, and they worked OK. I would never have bought a V6 petrol automatic, but it was free, and my other petrol town car, a manual, was away on loan.

Maybe I'm too critical because I know what is possible.

 

[Averagesupernova]

It works well on the flat or on highways, and throws no warning codes.

You said yourself that you suspected an issue with the control loop due to the converter. What makes you think the converter can be the only issue with the control loop? A leaky actuator will add a delay when it attempts to open the throttle.

 

[JT Smith]

That is really a statement about poor traffic engineering, and the lack of good public transport.

While I don't disagree that there's a lot of room for improvement with both those I certainly didn't mean it that way. There's a limit to what traffic engineers can do, practically, in a given situation. One can always dream but in the meantime you need to be able to get around.

 

[russ_watters]

Also, my car brakes when going downhill in cruise control. First I've seen do that and I'd prefer it didn't. Everyone has their preferences.

 

[Ranger Mike]

symbolipoint
had a question. is it answered to his satisfaction.


This question for any technical purposes is way out-of-my league.
How or why is it that replacing a dead car battery with a new battery would allow the car to stall while engine idling for 1, maybe 2 days, and then no further stalling after that? This should seem to make no sense. Typical modern car by well-known foreign manufacturer. Fuel-injected, in case that were important.

nuff said

 

[russ_watters]

symbolipoint had a question. is it answered to his satisfaction.

...nuff said

I've thought about splitting-off the digression, but because there doesn't seem to be anything more to say on the original topic, it doesn't seem to matter if it is split or not. Also, nobody reported the thread digression, so evidently nobody feels too strongly about it being a problem.

 

[tech99]

Yup, happened to me once. It's incredibly difficult to drive a manual transmission if you have to keep one foot on the gas all the time to avoid stalling.

Heel and toe for gear changing and hill starts is the essence of a good driver.

 

[berkeman]

Heel and toe for gear changing and hill starts

For hill starts, I've always preferred the emergency brake technique (but that assumes a hand-operated emergency brake lever).

 

[Baluncore]

Heel and toe for gear changing and hill starts is the essence of a good driver.

Early vehicles used a hand throttle, mounted on the steering column. There was no accelerator pedal in the model T Ford. Foot pedals were used to preselect a gear, then the other foot to operate the clutch.

 

[tech99]

I learned to drive with a crash gearbox (no synchromesh) and have always wanted to do so again. When braking and slowing, you need to use the heel-and-toe technique so you can rev the engine in neutral whilst simultaneously braking. Sorry this is a bit off topic.

 

[Baluncore]

I learned to drive with a crash gearbox (no synchromesh) and have always wanted to do so again.

Then compromise by avoiding use of the clutch. Adjust the transmission load to zero, then knock the synchro box into neutral, adjust the revs, then knock it into the next gear, and take up the load.
If you get the RPM wrong often enough, you will wear out the synchro rings, and end up with a real crash box. Have fun.

 

[sophiecentaur]

so why do people in the USA require so many cars to commute?

It's my precious and bus passengers smell. (Quote from a member of my family - and he's not even American)