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Discussion Starter · #1 ·
I need the knowledge of the engine experts on this forum....

Every vehicle I’ve owned in the past has had higher RPMs upon cold startup. After about 30-45 seconds the RPMs would reduce down to a “normal” idle speed.

I’ve always made it a practice to start the engine, wait for the RPMs to lower, and then place the vehicle into gear to drive. I remember being told that this was best for the engine.

The Ascent seems to run almost two minutes at higher idle speed before slowing down. Outdoor temps in our area have been in the 70s and the vehicle AC has been on - not sure if those factors make any difference.

So my questions are 1) is it “normal” for the Ascent to take so long to come to a regular idle speed? 2) should I wait until it comes to a regular idle speed before placing into gear? 3) would I be doing any long-term harm by only waiting a few seconds (say 30) after startup before driving?

It seems I would be wasting lots of gas over time if I always need to wait for the RPMs to slow down.

Thanks for the knowledge.
 

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I need the knowledge of the engine experts on this forum....

Every vehicle I’ve owned in the past has had higher RPMs upon cold startup. After about 30-45 seconds the RPMs would reduce down to a “normal” idle speed.

I’ve always made it a practice to start the engine, wait for the RPMs to lower, and then place the vehicle into gear to drive. I remember being told that this was best for the engine.

The Ascent seems to run almost two minutes at higher idle speed before slowing down. Outdoor temps in our area have been in the 70s and the vehicle AC has been on - not sure if those factors make any difference.

So my questions are 1) is it “normal” for the Ascent to take so long to come to a regular idle speed? 2) should I wait until it comes to a regular idle speed before placing into gear? 3) would I be doing any long-term harm by only waiting a few seconds (say 30) after startup before driving?

It seems I would be wasting lots of gas over time if I always need to wait for the RPMs to slow down.

Thanks for the knowledge.
I'm not an engine expert by any means, but I would say 30 seconds to 1 minute is perfectly fine. The most important thing to keep an eye on is the oil temp gauge and not race the engine until it's up to temp. (especially in cooler climates)

If the AC has been running and thus the compressor, I could see the engine RPMs running higher. I'd say that's very normal.

Edit: I personally try not to run the AC right when i start my vehicle unless it's truly needed. I usually start it after driving a bit. (that's any vehicle not just the Ascent)
 

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If you run your climate control in "Full Auto" the computer won't go full blast with the A/C for a few seconds after startup, anyway.

The goal of the higher engine idle is to get the oil from ambient, let's say 70 like you mentioned, up to proper temperature. From what I've seen on other Subie forums, it seems like 150F is really the minimum before you start hammering on it. That doesn't mean idle in park until you hit 150, it just means avoid high RPM's until you're there. A hot engine on a cold transmission isn't the best combo, either.

When the engine is warm, emissions and fuel consumption are both lower, so the computer hurries to get it up to speed.
 

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Discussion Starter · #4 ·
Thank you for your insight. I think I’ll try to make it a practice to let the engine warm up a few minutes and come to a normal Idle before driving whenever I can - but at the same time I won’t worry if I’m in a hurry and can only give it 30-45 seconds or so.
 

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High RPMs when on start

When I start my car and drive 5 mph to get out of the large parking lot, I see the RPMs are around 2000. The oil temp is 90F.

This is really high. When I drive 25mph RPMs are around 1500.

Is this normal since CVT is cold?

I don't remember any of my other cars (including Forester with CVT) do it.
 

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I need the knowledge of the engine experts on this forum....

Every vehicle I’ve owned in the past has had higher RPMs upon cold startup. After about 30-45 seconds the RPMs would reduce down to a “normal” idle speed.

I’ve always made it a practice to start the engine, wait for the RPMs to lower, and then place the vehicle into gear to drive. I remember being told that this was best for the engine.

The Ascent seems to run almost two minutes at higher idle speed before slowing down. Outdoor temps in our area have been in the 70s and the vehicle AC has been on - not sure if those factors make any difference.

So my questions are 1) is it “normal” for the Ascent to take so long to come to a regular idle speed? 2) should I wait until it comes to a regular idle speed before placing into gear? 3) would I be doing any long-term harm by only waiting a few seconds (say 30) after startup before driving?



It seems I would be wasting lots of gas over time if I always need to wait for the RPMs to slow down.

Thanks for the knowledge.
For those of us who start out climbing a stretch or hill in the morning, the engine indeed races....minimum 3000 of I drive a snail’s pace or over 4000 if I drive normal (and that’s after a 30 ish second idle in the driveway). It holds the RPMs a little bit after I go over the crest of the hill as well.

It SEEMS like I’m ripping the engine to shreds but the manual is clear: the car runs better when warmed up, and is designed to do that as rapidly as possible. Idling cars simply don’t warm up very fast even if you’re sitting there watching the needle move... they warm up primarily under load. I’m sure the engineers have considered that the high RPMs after cold start are preferable to slow warm ups in terms of longevity, economy and emissions.

My 2013 impreza does this too but not as dramatically as the Ascent. Given how much the engine revs, I bet most people would notice and wonder.
 

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New owner of a 2021 Ascent Ltd. We live in South Texas where the temperature in the morning is not cold. When I first start the car, the idle runs at 1800 RPM. This seems excessively high for a cold engine start when the outside ambient is over 60F. It also makes it very difficult to back out of the garage without power breaking to control the speed. It is much more manageable to back out with a normal ideal at around 6-800 RPM. This seems excessively high for a cold engine start when the outside ambient is over 60F. Especially when my daughter’s 2021 Ascent doesn’t do this in Flagstaff where the morning temps are between 15-20 deg most days. Is there a Peak Cold Idle adjustment that can be made?
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That's just the way these cars are, I'm afraid. Interestingly, the loaner Outback and Forester I've had recently will lower the cold idle to about 1,100 RPM if you slide the transmission back into neutral first...the idle settles down and then you can put it into drive or reverse from there. No joy with the Ascent, however...it just races away at 1,800 RPM for a short while. After a minute or two, ours will eventually settle down. Backing out of the garage is a bit tedious with the racing engine, but it is what it is.

The throttle and idle speed are all electronically controlled and are not adjustable.
 

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New owner of a 2021 Ascent Ltd. We live in South Texas where the temperature in the morning is not cold. When I first start the car, the idle runs at 1800 RPM. This seems excessively high for a cold engine start when the outside ambient is over 60F.
This is normal behavior so that the turbo system gets heated up to an efficient level quickly. What's "warm" to you and I is not the same as "warm" to a vehicle's engine and components like a turbocharger. It's not about weather...it's about operating temperature. Yes, it can be annoying if one is in a hurry to depart, but that higher RPM doesn't last for a long time.
 
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Remember, 60° is quite cold for an engine. Coolant temp is about 195°, oil temp is between 180-210°, catalytic converter temp hits 800-1,200°. Emissions reasons are a key reason for the high idle, to warm up the cat.
 

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Every vehicle I’ve owned runs in high idle for around the same amount of time. My Ridgeline was a little different in that it seemed to go in stages, around 2200 for 30sec, then 1500 or so for another 30, then down to 900. The Ascent runs fast for a little over a minute, perhaps a bit longer lately as it’s been below -30C, (well into the -40’s with wind) for the last few days. A bigger annoyance is it takes another 5 min for the CVT to stop whining in these temps.
 

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Especially when my daughter’s 2021 Ascent doesn’t do this in Flagstaff where the morning temps are between 15-20 deg most days.
I missed this the first time I saw your post -- you're saying your daughter's 2021 Ascent doesn't have a high cold idle? What is the cold idle on her car? That is definitely outside the norm for these cars. If her car starts up and idles at 1,000 or 1,200 RPM or something even on a cold morning -- that's definitely not like the rest of our cars.
 

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it just races away at 1,800 RPM for a short while. After a minute or two, ours will eventually settle down. Backing out of the garage is a bit tedious with the racing engine, but it is what it is.
My Ascent starts at high RPMs too but drops below 1000 immediately when I shift into reverse.
 

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My Ascent starts at high RPMs too but drops below 1000 immediately when I shift into reverse.
Well...right, when the engine is loaded down against the transmission in either reverse or drive. Unfortunately, the transmission is absorbing all that kinetic energy at the flywheel and torque converter when this happens.

I took the "cold idle" discussion above to mean when in park or neutral, unloaded by the transmission.
 

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This is normal behavior so that the turbo system gets heated up to an efficient level quickly. What's "warm" to you and I is not the same as "warm" to a vehicle's engine and components like a turbocharger. It's not about weather...it's about operating temperature. Yes, it can be annoying if one is in a hurry to depart, but that higher RPM doesn't last for a long time.
Jim, I'm new to the Ascent. I've done my due diligence, having searched this forum and the internet regarding the cold start/fast idle to slow idle issue to answer my question: Should I wait and let the idle reduce to the lower idle RPM at cold startup prior to driving? That's what I've been doing. I'm at 1800 miles. I saw your or Robert's post about this a few weeks ago but can't find it - I thought it said to wait for the normal idle prior to driving. Been searching for about an hour while watching football. Thanks for your help! PS - I couldn't find anything in the manual on this (chapter 7).
 

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Jim, I'm new to the Ascent. I've done my due diligence, having searched this forum and the internet regarding the cold start/fast idle to slow idle issue to answer my question: Should I wait and let the idle reduce to the lower idle RPM at cold startup prior to driving? That's what I've been doing. I'm at 1800 miles. I saw your or Robert's post about this a few weeks ago but can't find it - I thought it said to wait for the normal idle prior to driving. Been searching for about an hour while watching football. Thanks for your help! PS - I couldn't find anything in the manual on this (chapter 7).
No reason to do that. Get in, start it up and drive it. Just realize it will feel a little wonky at the get-go, but this quickly resolves.

If your trips are all relatively short, it will feel like the car behaves this way "all the time" but that's not the reality of it.
 

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my question: Should I wait and let the idle reduce to the lower idle RPM at cold startup prior to driving?
No, that's not necessary. You can head out when you are ready. The higher RPM for heating will only continue for a few minutes and then drop back, even while driving. Sitting at idle, especially fast idle, is going to impact your fuel economy in a negative way for no gain.
 

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What Jim said. Part of what you will experience is the car taking its time to down shift, as the CVT holds higher ratios to keep the engine RPM's higher while the car is warming up.
 

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Robert and Jim, Thanks for the information and clearing that up for me.
 

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Does anyone else's Ascent produce a pretty apparent single "click" sound when shifting from park to reverse when cold and at high idle? Ours parks in our garage and it'll make a loud "click" or "tick" sound just once when reverse engages. This is only when cold and at high idle. I presume this is normal, but am curious to know if others do the same.

(I should clarify, this is different from the normal chirp heard when shifting into drive when cold.)
 
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