High Idle Duration

[V8 Yankee]

Morning all, curious if any motorheads have the same high idle duration on their 1.5 BS as do. If I leave my engine off for 10 minutes and restart the cold start idle programming kicks in, the duration is for approx. 30 to 60 seconds at 15-1800 rpm. Not an issue if I restart under 10 minutes of being off. The engine normally idles at or below around 900 normally.

Now I understand the sensors need to register adequate temperature and oil pressure before signaling the high idle dashpot (old school terminolgy) to disengage. Now days its more of a electro/mechanical/programming action than purely a mechanical action.

I'm one to always wait till low idle before engaging the transmission. It's a small issue but sometimes that 60 seconds of waiting for the rpms to drop below 1000 seems like 5 minutes. Just curious if anyone noticed this and if it's common across the board, if so than its baked into the programming. If not I'm curious if the idle idle dration can be adjusted.

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[Petroph]

Don't have a 1.5, but I can say that the 2.0 does not have this issue, at least for me right now.

 

[Meanderthal]

Morning all, curious if any motorheads have the same high idle duration on their 1.5 BS as do. If I leave my engine off for 10 minutes and restart the cold start idle programming kicks in, the duration is for approx. 30 to 60 seconds at 15-1800 rpm. Not an issue if I restart under 10 minutes of being off. The engine normally idles at or below around 900 normally.

Now I understand the sensors need to register adequate temperature and oil pressure before signaling the high idle dashpot (old school terminolgy) to disengage. Now days its more of a electro/mechanical/programming action than purely a mechanical action.

I'm one to always wait till low idle before engaging the transmission. It's a small issue but sometimes that 60 seconds of waiting for the rpms to drop below 1000 seems like 5 minutes. Just curious if anyone noticed this and if it's common across the board, if so than its baked into the programming. If not I'm curious if the idle idle dration can be adjusted.

Higher idle is trying to warm things up, so does driving. Letting the car sit and idle is only burning gasoline for no other real benefit. Of course, I don’t mean that you should put the pedal to the metal right away but driving normally is a benefit to warmup where idling doesn’t help things outside the engine warm up (like the transmission and differential).

 

[V8 Yankee]

Higher idle is trying to warm things up, so does driving. Letting the car sit and idle is only burning gasoline for no other real benefit. Of course, I don’t mean that you should put the pedal to the metal right away but driving normally is a benefit to warmup where idling doesn’t help things outside the engine warm up (like the transmission and differential).

Yes, U are right, that is common knowledge, Warming an engine up is essential on cold starts. The issue is my vehicle is already at operating temperature. It takes 3 hours to cool down here in southern Florida, not 10 minutes. The oil pressure takes a few seconds to reach full pressure but not 60 seconds. The high idle is programmed for both temp and oil pressure.

Maybe I didn't clarify this adequately on my initial post. I am really fishing for information. 1. Is this a common event with other 1.5 engines. 2. Is it adjustable and if so how. I think it's an easy fix if in fact it needs a fix at all. It's more of a inconvenience waiting for it to idle down.

 

[Flash]

When I start up, the engine goes into high idle, I fasten my seat belt, put it in gear and away I go. I hold the revs down until the engine has warmed up however.

 

[Deleted member 6350]

Yep 1.5 high idle approximately 45 seconds, I don‘t shift into any gear until the idle comes down also. It is what it is.

 

[tjbronco]

Our other car is a 2020 Outback - it idles at approx 1800 rpm for about 30-45 seconds on startup - I Googled about it and the info I found said that it is for emission reasons to warm the CAT up a bit quicker. You have to be careful putting it in gear if you try to drive off in that window. My Bronco Sport does not idle anywhere near that on start up - it seems much slower by comparison.

 

[V8 Yankee]

It's an old post of mine but still a minor issue, even a non-issue but a little perplexing. Where I grew up in eastern Washington letting your engine warm up, especially in winter where temperatures were below freezing was a thing for 3 months a year. The rule was to never ever put your transmission in gear until the engine idled down, even then wait a few minutes until the heater started blowing warm air before engaging. Metal needs to warm up before any engagement of gears or bad things might happen. Flash forward 45 years and I am now in sunny Florida where 60 degrees seems cold. Yes, it's a Florida thing. My 1.5 still has the same high idle duration it had since new. Could be a cold start which is normal or a hot start where it's already at temp. The duration is anywhere from 30 seconds to 45 seconds. Even at 100 degrees ambient and only 5-10 minutes of being off it will high idle at 14-1500 then go down to 900 or so. If there is any way to adjust this, I would be open to ideas. And not just throw it into gear and start driving, might be a sensor, or maybe programming, even a vacuum leak. After almost 3 years I am still looking for answers. Even the Ford techs have said they don't know. Drives me crazy that they just throw it into gear after starting, obviously they are not familiar with real winters down here. With the chatter about transmission failures, I am more cognizant than ever that maybe my BS isn't as tough as I think it should be.

 

[RushMan]

When I start up, the engine goes into high idle, I fasten my seat belt, put it in gear and away I go. I hold the revs down until the engine has warmed up however.

I do the same. My car is in my attached garage and I'm not going to sit there generating exhaust fumes in my garage. I put it gear, back out of the garage, and then stop in the driveway for a few seconds, while closing the garage door. And off I go! Usually by then, the idle has already dropped back.
On some cars, there is even an additional injector, called the cold start injector in the intake runner, that provides the additional fuel for cold starting. Interestingly, my '04 BMW X3 would flash the dash display with a message when the OAT was less than 37F, as a reminder to drive gently until the engine warms up.
The issue with extended idling is that a cold start provides additional fuel. A cold engine also has a larger amount of blow-by that a fully warmed up engine - thermal expansion of the piston rings and all that materials science stuff (I am a retired Materials Scientist). Extended idling increases the chances for oil dilution, which can prematurely reduce oil life.
Even on the coldest days, I drive off immediately, but drive gently until the engine reaches full operating temperature. That only takes a few miles/minutes. In comparison, in the winter, several of my neighbors have their cars idling for 15-20 minutes in their driveways before they leave for work. Little do they know what damage they are incurring on their engines.
You can find articles by Bob The Oil Guy and The Motor Oil Geek on the topic of oil dilution by excessive idling.

 

[Mark S.]

Drives me crazy that they just throw it into gear after starting, obviously they are not familiar with real winters down here. With the chatter about transmission failures, I am more cognizant than ever that maybe my BS isn't as tough as I think it should be.

Idling the car for more than a minute or so before driving is unnecessary, even in colder climates. Older carbureted engines needed a longer warmup time because carburetors do not do a good job of atomizing the fuel in colder temperatures. That's not an issue with modern fuel injected engines. The primary concern for newer engines is ensuring oil is distributed throughout the engine before driving it, and with 5WXX oil that happens within the first 30-60 seconds after starting.

Start the car, let it idle while you put on your seatbelt, adjust the mirrors, and get your phone connected, then drive it carefully--no hard acceleration--for the first five or ten minutes (depending on ambient temperature). This is the fastest way to warm up the engine, which saves fuel and decreases emissions.

https://www.consumerreports.org/cars/cars-driving/should-you-warm-up-your-car-before-driving-a5580016349

https://www.autozone.com/diy/seasonal/warming-up-your-car-winter-start-up

https://www.aaa.com/autorepair/articles/how-long-to-warm-up-the-engine-before-driving

 

[V8 Yankee]

I agree with excessive idle time, it does waste fuel that is better used just driving down the road in certain conditions. In my experience growing up in the great white north warming your engine and trans up before driving was an engine and transmission saver. All of our cars and trucks went beyond 200K. My brother still has the Ford 9N my grandfather bought new in the 40s. Never did we start it and drive away, warm up was just a thing and it still runs like new. Now granted old school technology doesn't compare to modern tech. But there is another element to just warming equipment up. There is resonance in the metals that make up everything mechanical. This I learned working around heavy industrial equipment and various types of machinery in metals production. We called in technicians that specialized in measuring the resonance to determine bearing and other rotating components life cycle. The resonance changed during the warm-up cycle. This change was critical and measured before any equipment was put into production mode. Without warm up, even when no stress was on the equipment there was measurable wear. Engines going from zero to 200 degrees have different stresses, heat related stresses, expansion and contraction, torque stress, lubrication, loads, etc. A little off subject as I'm really just looking for high idle duration information. It is however an interesting subject when you get into the weeds of mechanical stresses and how temperature is critical to everything mechanical. Not only temperature but other factors as well.

 

[Major Kong]

verily, all components are not equally created
cold weather is hell on plastics and rubber
the colder the worse
gaskets, seals, boots
vacuum operated sluggish groans
not considered a waste if a trivial amount of fuel is consumed for warm up
engines probably warm up quicker than most drivers
seems more than half are still asleep behind the wheel
good mental warm up period for the driver

 

[V8 Yankee]

Very true, there is another factor to consider. And it is related to low and high idle torque. When the 1.5 is in high idle (1500 rpm) torque is roughly 40 lbs. At low idle (900 rpm) the torque is less than 18 lbs. It doesn't sound like much but when the engine and trans are cold it becomes a factor in the long term. Not so much where I live now where temps rarely get below 60. In places were its below freezing for 3 months straight it is an issue. The 1.5 is a light weight engine, torque is amplified and not absorbed by the sheer weight of heavier, beefier platforms. Because this engine doen't have any long term statistics, let's say over 100K stats it's hard to say without having these stats just how long this engine will go. So far I haven't seen any info on these's 1.5s hitting the 200K mark. The 200K mark is generally a good mark for an engine to make it to. It seems these 1.5s are 100K motors at this point, I hope I'm wrong.

 

[BSBB4Les]

I'm on the side of letting the high idle do its thing. I get antsy sometimes, especially when running late, however, all things being equal, we're still driving vehicles with a gas combustion, oil filled engine and a fluid filled transmission. Better safe than sorry is my mantra! Besides, I'm an old fart. Old habits die hard!

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