Start Stop
Elder User
Joined: Aug 2005
Posts: 536
Likes: 5
From: Phoenix, AZ
Here's the list from the service manual of when the start/stop system WON'T operate:
The Auto-start-stop system may not turn the engine off under these conditions:
The Auto-start-stop system may not turn the engine off under these conditions:
- the HVAC system is in A/C, heat or defrost modes.
- the rear defroster is on.
- the battery has a low state of charge.
- the battery temperature is below 5°C (41°F) or above 60°C (140°F).
- the engine temperature is below 46°C (115°F).
- the engine temperature is below 60°C (140°F) and the HVAC system is in heat mode.
- the gear selector is not in Drive or Sport Mode.
- the steering wheel is turned rapidly or is at a sharp angle.
- vehicle speed of greater than 4 km/h (2.5 mph) for more than 2 seconds has not occurred.
- the vehicle is on a steep road grade.
- elevation is approximately above 3,048 meters (10,000 feet).
Senior User
Joined: Jun 2004
Posts: 155
Likes: 4
From: Tennessee USA
You do know that we're not referring to the AC being turned off. I doubt that your AC compressor never stops compressing.
Elder User
Joined: Aug 2006
Posts: 634
Likes: 2
I'd love to see a tare down of one of these stop/start engines after 100k, and see what all those dry starts do. (Especially guys who don't use a full synthetic motor oil, I see bad engines after the powertrain warranty expires). I doubt Ford changed to an electric oil pump.
In addition, I wonder how many EcoBoost turbos will fail by shutting off the engine before the turbo can cool off and spin down......which is literally minutes before the shaft stops spinning.
In addition, I wonder how many EcoBoost turbos will fail by shutting off the engine before the turbo can cool off and spin down......which is literally minutes before the shaft stops spinning.
Cross-Country
Joined: Jan 2010
Posts: 73
Likes: 1
I have my 17 set to max cool all the time and it shuts off all the time. However, I have not tried it with the blower on the highest setting to see if it shuts off. With the blower on 4 or 5, when the motor turns off, the blower slows way down.
Edit: I tested this morning, if I have the blower set on max the start/stop is disabled. So that is good to know.
Edit: I tested this morning, if I have the blower set on max the start/stop is disabled. So that is good to know.
Laughing Gas
Joined: Mar 2004
Posts: 1,019
Likes: 6
From: Fountain Valley
I've ordered an 18 should be here the end of Sept. Start/stop is only a starter problem concern for me. I've had many apart but never on an engine that starts as quickly as these newer cars. Hopefully longevity won't be a major problem. I've sold my 13 ECO for a 5.0 and looking forward to a V8 again even tho the 3.5 towed as good as the diesel it replaced.
Lead Driver
Joined: May 2015
Posts: 5,870
Likes: 356
From: Mts. S. of San Francisco
I'd love to see a tare down of one of these stop/start engines after 100k, and see what all those dry starts do. (Especially guys who don't use a full synthetic motor oil, I see bad engines after the powertrain warranty expires). I doubt Ford changed to an electric oil pump
Fleet Mechanic
Joined: Feb 2017
Posts: 1,597
Likes: 83
From: N. Texas
Please explain. Unless Ford switched to an electric oil pump, how can a non-running engine maintain oil pressure?
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Lead Driver
Joined: May 2015
Posts: 5,870
Likes: 356
From: Mts. S. of San Francisco
Example: https://www.edmunds.com/ford/f-150/2...-you-wait.html
There are other things at play too, such as special anti-scuff coatings on the main bearings and so on.
Post Fiend
Joined: Jun 2014
Posts: 6,801
Likes: 7
From: DFW, TX-GoldCanyon, AZ
.....and......
It's a long held fallacy that engine bearings need oil pressure to "float" them.
All it really takes is a very thin film of oil to keep the bearings from scuffing.
Oil pressure creates flow which then carries heat away from the bearings and journals.
I'm not at all concerned about the engine...
It's a long held fallacy that engine bearings need oil pressure to "float" them.
All it really takes is a very thin film of oil to keep the bearings from scuffing.
Oil pressure creates flow which then carries heat away from the bearings and journals.
I'm not at all concerned about the engine...
Fleet Mechanic
Joined: Jul 2005
Posts: 1,463
Likes: 103
From: Staten Island, NY
They might use an electric pump (IDK). However, I've read on Edmunds and elsewhere that it is more of a passive means to hold the oil in galleries and such. There might be a check valve (I'm speculating there), but the article I read was about having to wait ~~ 15 minutes for the oil to drain back.
Example: https://www.edmunds.com/ford/f-150/2...-you-wait.html
There are other things at play too, such as special anti-scuff coatings on the main bearings and so on.
Example: https://www.edmunds.com/ford/f-150/2...-you-wait.html
There are other things at play too, such as special anti-scuff coatings on the main bearings and so on.
Senior User
Joined: Aug 2004
Posts: 159
Likes: 0
What's left? Off?
Fleet Mechanic
Joined: Jul 2005
Posts: 1,463
Likes: 103
From: Staten Island, NY
Well, there is that. Also the system WILL shut down the engine when the cabin temperature is within a degree or two of the set-point in heat or A/C but NOT in defrost. Also, in Heat mode there is an electric pump which keeps hot water circulating through the heater core when the engine shuts down.
Elder User
Joined: Aug 2005
Posts: 536
Likes: 5
From: Phoenix, AZ
It look like the feature is activated based on temp, not what you have set. I was really disturbed by the shaky restart. Didn't sound good. ????
Fleet Mechanic
Joined: Jul 2005
Posts: 1,463
Likes: 103
From: Staten Island, NY
I have to re-track this statement " MAX COOL does NOT stop Auto Start/Stop. This morning, Max cool was on, I came to a stop light and the motor shut off. It was only 92 outside temp. As I waited for the light to change, the AC blower had stopped running, a very eerie silence and before the light changed, the engine cranked over 3-4 times, it started but was like shuttering, it then smooth out (Note I still had my foot on the brake). The light changed and off I went.
It look like the feature is activated based on temp, not what you have set. I was really disturbed by the shaky restart. Didn't sound good. ????
It look like the feature is activated based on temp, not what you have set. I was really disturbed by the shaky restart. Didn't sound good. ????
I wouldn't worry about the shudder. It's normal. Remember the engine is restarting against a trans that's still locked into first gear by the electric pump in the trans. Not like starting up in park or neutral.