How do Cold Starts Work on the 4xe?

DavidArmen

Well-Known Member
First Name
David
Joined
Sep 19, 2020
Messages
765
Reaction score
647
Location
Hollywood, CA
Vehicle(s)
2021 Red JLUR
I have a question for all the 4xe owners regarding something I’ve wondered about recently.

I have the 3.6 pentastar and I warm up my engine for about ten minutes during every cold Start.

I’ve read on the forums that for the 4xe the engine does not turn on when the start button is pressed because it always starts up in hybrid mode.

So how does this work with the 4xe? Is warming up an ICE engine a thing of the past for the 4xe?

So I know the engine doesn’t start with the button, but what if you get in the jeep on a cold early morning and start it? Does anything change in that scenario? Does the engine kick in to warm up (even if you’re in hybrid/electric mode) and then shut off when it reaches operating temperatures?

However, if the engine doesn’t automatically start in the morning to warm itself up, there are a few scenarios that I am curious about.

One scenario is if you’re driving and you get on the freeway ramp and you slam the accelerator pedal to the floor, this will force the engine to turn on so it can accelerate you better from what I’ve read, correct? So if the engine is cold because it never ran that day, will it just rev up to redline? Won’t this be detrimental for a cold engine?
Advertisement

 
Joined
Apr 24, 2021
Messages
21
Reaction score
16
Location
Little Switzerland, NC
Vehicle(s)
2018 Subaru Crosstrek, 2021 JLURe (coming soon)
Modern engines don't need to be warmed up before driving in cold weather. In fact, idling a cold fuel-injected engine is worse for it than driving it cold because it will use a richer fuel-air mixture, leading to unused gas passing through the engine and stripping oil from places where it's needed.

I would, however, recommend against slamming the pedal to the floor on frigid days when the engine hasn't turned on yet.
 

Echo4papa

Well-Known Member
First Name
Scott
Joined
May 6, 2021
Messages
324
Reaction score
399
Location
Florida
Vehicle(s)
2021 Sahara 4xe
Occupation
Success Engineer
If that's your daily drive (hoping on the freeway shortly after start up), you just put it in eSave mode when you get in to force the ICE on prior to hitting I-5 and sitting in traffic (assuming that's still how traffic is in LA).

I used to "commute" in my '86 CJ-7 from Laguna Niguel to Pendleton and I do not miss the traffic in Southern California one bit.
 

Sboden

Well-Known Member
Joined
Apr 18, 2020
Messages
578
Reaction score
451
Location
Kansas City
Vehicle(s)
2021 JLUR 4Xe, 2.5" lift, 17" wheels, 37" tires
When entering the freeway, with traffic going 75 to 80 mph, I'm still using a ton of electric and the engine rpm isn't getting up very high. I have plenty of power to merge. If you floor it, you could get your rpm up there while it is cold.
 
OP
OP
DavidArmen

DavidArmen

Well-Known Member
First Name
David
Joined
Sep 19, 2020
Messages
765
Reaction score
647
Location
Hollywood, CA
Vehicle(s)
2021 Red JLUR
David, I'm pretty sure you DO NOT have to let the Jeep warm up for 10 minutes EVER in Hollywood.

Just sayin'

G. :CWL:
Hahaha that’s very true but I start it up from home and it warms up before I get in it and it also warms the cabin a little for me cause it’s about 50 degrees here at 6am. Y’all can laugh but 50 is pretty cold for a Los Angeleno😂


If that's your daily drive (hoping on the freeway shortly after start up), you just put it in eSave mode when you get in to force the ICE on prior to hitting I-5 and sitting in traffic (assuming that's still how traffic is in LA).

I used to "commute" in my '86 CJ-7 from Laguna Niguel to Pendleton and I do not miss the traffic in Southern California one bit.
Yeah traffic levels are about 85%-90% back to pre-Covid levels here in Los Angeles. I consider myself lucky I never have to drive on the 5 or 101 or 405 during rush hour traffic else I’d go completely mad.
 

Echo4papa

Well-Known Member
First Name
Scott
Joined
May 6, 2021
Messages
324
Reaction score
399
Location
Florida
Vehicle(s)
2021 Sahara 4xe
Occupation
Success Engineer
Remote start to warm/cool the cabin works just fine by the way. Actually, it's fucking fantastic. I used it on my Mustang and it took a while to get cold and cool off the car, but this thing cools off the Jeep pretty damn quick.
 

Jamie Brown

Active Member
First Name
Jamie Brown
Joined
Jan 31, 2021
Messages
43
Reaction score
36
Location
Blythewood SC
Vehicle(s)
GMC 3500AT4, Nissan Leaf, RAM 4500
I have a question for all the 4xe owners regarding something I’ve wondered about recently.

I have the 3.6 pentastar and I warm up my engine for about ten minutes during every cold Start.

I’ve read on the forums that for the 4xe the engine does not turn on when the start button is pressed because it always starts up in hybrid mode.

So how does this work with the 4xe? Is warming up an ICE engine a thing of the past for the 4xe?

So I know the engine doesn’t start with the button, but what if you get in the jeep on a cold early morning and start it? Does anything change in that scenario? Does the engine kick in to warm up (even if you’re in hybrid/electric mode) and then shut off when it reaches operating temperatures?

However, if the engine doesn’t automatically start in the morning to warm itself up, there are a few scenarios that I am curious about.

One scenario is if you’re driving and you get on the freeway ramp and you slam the accelerator pedal to the floor, this will force the engine to turn on so it can accelerate you better from what I’ve read, correct? So if the engine is cold because it never ran that day, will it just rev up to redline? Won’t this be detrimental for a cold engine?
When mine starts when the battery runs out the engine goes to around 1800 RPM. Even in a parking lot driving slow it sounds like I am trying to fly through the parking lot while coasting. I hate it and wish I could reprogram it to just idle like a normal engine.
 

Black96z

Active Member
First Name
David
Joined
Sep 3, 2020
Messages
37
Reaction score
25
Location
Houston
Vehicle(s)
2021 Rubicon 4XE, Tesla Model S
Occupation
Machinist, Applications Engineer
When the 4XE starts the engine, it idles pretty high to warm up the engine. This happens if you are parked or going down the freeway. Unless you floor it for more power, the engine will start and kick in to high idle until it warms to about 150°F and then it will go to normal idle, or start providing power. If you are on the freeway, you will see the engine kick on and idle for 30 sec-1 min before the revs come up and start providing power.
 

Terminex

Well-Known Member
First Name
Matt
Joined
Apr 19, 2019
Messages
478
Reaction score
391
Location
Omaha
Vehicle(s)
2019 JLUS
Occupation
Fixing stupid....
If that's your daily drive (hoping on the freeway shortly after start up), you just put it in eSave mode when you get in to force the ICE on prior to hitting I-5 and sitting in traffic (assuming that's still how traffic is in LA).

I used to "commute" in my '86 CJ-7 from Laguna Niguel to Pendleton and I do not miss the traffic in Southern California one bit.
+1 for this. When i was in high school, i hated going south on the 405 in rush hour. Having to cross 8 lanes of bumper to bumper traffic in 1/4 of a mile to get off at Lake Forest. (That is where the 405 & 5 freeways come togethor)
 
Advertisement

Rancho
 
Advertisement
Top