How long for your 4.0L to warm up to 195F/730rpm? - JeepForum.com
 18Likes
Reply
 
LinkBack Thread Tools
post #1 of 40 Old 03-10-2019, 05:54 PM Thread Starter
soyjer
Registered User
 
Join Date: Jan 2019
Posts: 16
How long for your 4.0L to warm up to 195F/730rpm?

Idling from a cold (50F) start, it takes my 1999 4.0L 7 minutes to reach 195F (1/2 of a hash mark below the 210F hashmark) and 730rpm (needle slightly below the hashmark that is below "1" on the tach).

How long does it take YOUR 4.0L to warm up to 195F/730rpm?

I've been told that 7 minutes is WAY too long, and yet my thermostat appears to be fine (not stuck open), because the heater hose gets too hot to hold onto in 7 minutes, whereas the upper radiator hose stays completely cold for 7 minutes.

soyjer is offline  
Sponsored Links
Advertisement
 
post #2 of 40 Old 03-10-2019, 07:27 PM
tyvanwie
Registered User
 
tyvanwie's Avatar
1993 XJ Cherokee 
 
Join Date: Sep 2012
Location: Boone
Posts: 9,896
I’d be surprised if mine warms up that quickly and it’s a 93. 7 minutes doesn’t seem too long to me. Tonight when I get off work I will actually time it and report back.
tyvanwie is online now  
post #3 of 40 Old 03-10-2019, 08:10 PM
2oldjeeps
Registered User
2000 XJ Cherokee 
 
Join Date: Aug 2017
Posts: 847
? time?...3 miles slow driving, or less...
TheBoogieman and wichol98 like this.

99wj,143,000 miles
00xj,177,000 miles
10hummer3,74,000 miles
98xj,130,000 miles
2oldjeeps is offline  
 
post #4 of 40 Old 03-11-2019, 06:02 AM
TheBoogieman
Disturbed Jeepaholic
 
TheBoogieman's Avatar
2003 TJ Wrangler 
 
Join Date: Aug 2006
Location: CharlottesHELL
Posts: 38,116
It warms up faster if you drive it.

Quote:
Originally Posted by jeepinmichguy_ View Post
TheBoogieman is a jerk.
03' Rubicon/Zone 4.25" combo lift/Rancho 9000XL shocks/5.13 gears-35" MTZs/LoD bumpers/Black Magic brakes
Desert Sand 99' XJ Classic (JEEP #18) ) 5" BDS lift / HP30/ 8.25/ 33x12.50" DC Extreme Country/Tactik black satin wheels.
TheBoogieman is offline  
post #5 of 40 Old 03-11-2019, 07:06 AM
cruiser54
Web Wheeler
 
cruiser54's Avatar
1990 MJ Comanche 
 
Join Date: Oct 2009
Location: Prescott
Posts: 11,905
Quote:
Originally Posted by TheBoogieman View Post
It warms up faster if you drive it.
Yes. And 7 minutes would seem great to me.

If you own a Renix Jeep, you must check this out:


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


My Jeep technical photos:


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
cruiser54 is offline  
post #6 of 40 Old 03-11-2019, 07:47 AM
gutthans
Senior Member
 
gutthans's Avatar
1995 YJ Wrangler 
 
Join Date: Jun 2018
Location: Deland
Posts: 520
Garage
Warm-up time will vary with ambient air temp and whether it's idling or running down the road. 7 minutes is well within the ballpark on cold days. (Note: If you have a block heater or other method for pre-heating the motor it will come up to operating temps much faster).
gutthans is offline  
post #7 of 40 Old 03-11-2019, 02:04 PM
PhilipJ
Registered User
1999 XJ Cherokee 
 
Join Date: Feb 2004
Location: PNW
Posts: 1,577
Not sure about straight idle time, but it takes a little over 3 minutes at 25 MPH for me, and that's without any fans going as mine are electric and don't come on until 195F.
PhilipJ is offline  
post #8 of 40 Old 03-11-2019, 04:43 PM
CJ7-Tim
Real Jeeps have dents
 
CJ7-Tim's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2002
Location: out in the garage - Minneapolis
Posts: 26,975
I am totally confused as to the usefulness of data about the warm up time, but was intrigued enough to roughly time my 1998. Today it was 30 and when I started the engine the idle rpm's began to fall within one minute after starting. With careless disregard for the consequences, I put the AW-4 into gear, and drove off, as I have for the past 17 years of XJ ownership. I drove about 30 mph on city streets and the temp gauge began to rise after about 3 minutes. At about 5-6 minutes of driving the gauge had risen to about 195.
TheBoogieman and downs like this.

.

A recent Gallup public opinion poll shows the NRA, at 58% approval, has a higher approval rating than either Hillary Clinton or Barack Obama.

Progressive Liberalism: Bringing you new Healthcare ideas so wonderful, they have to include mandatory participation ...

Originally Posted by Ronald W. Reagan: Government is not the solution to our problems; Government is the problem.
CJ7-Tim is offline  
post #9 of 40 Old 03-12-2019, 11:23 AM Thread Starter
soyjer
Registered User
 
Join Date: Jan 2019
Posts: 16
Thanks...mine is starting at 50F, but my results are similar. I still need to know how long it takes to reach ~730rpm idle speed, though. I THINK that idle speed continues to lower slowly as temp rises slowly, and they finally both simultaneously reach 195F/730rpm....I think this is how the PCM is programmed.

My obsession with this is because my XJ has a clunk/lurch problem that even veteran Jeep Master Technicians and expert professional transmission technicians cannot figure out. Complete rebuild of transmission didn't faze the problem at all. Just grasping at straws, at this point.



Quote:
Originally Posted by CJ7-Tim View Post
I am totally confused as to the usefulness of data about the warm up time, but was intrigued enough to roughly time my 1998. Today it was 30 and when I started the process of engine the idle rpm's began to fall within one minute after starting. With careless disregard for the consequences, I put the AW-4 into gear, and drove off, as I have for the past 17 years of XJ ownership. I drove about 30 mph on city streets and the temp gauge began to rise after about 3 minutes. At about 5-6 minutes of driving the gauge had risen to about 195.
soyjer is offline  
post #10 of 40 Old 03-12-2019, 11:29 AM
CJ7-Tim
Real Jeeps have dents
 
CJ7-Tim's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2002
Location: out in the garage - Minneapolis
Posts: 26,975
As was suggested previously in your transmission rebuild thread, the AW-4 is a very firm shifting transmission, and 18 or more years of usage has put some wear on the differential. Clunking Chrysler axles are nothing new.

In my opinion, all of this falls under : If it ain't broke, don't fix it. YMMV.
TheBoogieman and downs like this.

.

A recent Gallup public opinion poll shows the NRA, at 58% approval, has a higher approval rating than either Hillary Clinton or Barack Obama.

Progressive Liberalism: Bringing you new Healthcare ideas so wonderful, they have to include mandatory participation ...

Originally Posted by Ronald W. Reagan: Government is not the solution to our problems; Government is the problem.
CJ7-Tim is offline  
post #11 of 40 Old 03-12-2019, 12:20 PM Thread Starter
soyjer
Registered User
 
Join Date: Jan 2019
Posts: 16
https://www.naxja.org/forum/showthread.php?t=1146705

I appreciate your help. Unfortunately, because I have no other XJ's around to compare to, I am having to rely on professionals and forums to tell me what is normal for an XJ. All of them agree that my clunk/lurch is abnormal and damaging, and not anything other than the transmission, and yet extensive transmission work and analysis finds nothing. I even bought my own line pressure gauge, just to make sure that it isn't a line pressure problem...desperation.
The best clue to the source of the problem is that if I shift to reverse before drive, especially when cold, then sometimes it won't clunk. It NEVER clunks into reverse, btw. Idle is 730rpm.
soyjer is offline  
post #12 of 40 Old 03-12-2019, 12:49 PM
gutthans
Senior Member
 
gutthans's Avatar
1995 YJ Wrangler 
 
Join Date: Jun 2018
Location: Deland
Posts: 520
Garage
Quote:
Originally Posted by soyjer View Post
https://www.naxja.org/forum/showthread.php?t=1146705

I appreciate your help. Unfortunately, because I have no other XJ's around to compare to, I am having to rely on professionals and forums to tell me what is normal for an XJ. All of them agree that my clunk/lurch is abnormal and damaging, and not anything other than the transmission, and yet extensive transmission work and analysis finds nothing. I even bought my own line pressure gauge, just to make sure that it isn't a line pressure problem...desperation.
The best clue to the source of the problem is that if I shift to reverse before drive, especially when cold, then sometimes it won't clunk. It NEVER clunks into reverse, btw. Idle is 730rpm.
Drive...will be in the same torsional direction as the normal rotation of the input. Reverse will at some point create torque in the opposite direction. That MAY indicate a loose/worn torque control arm, or perhaps a worn/loose u-joint in the driveline. Something has just enough play to give you that clunk.

I suppose you could firmly support the rear axle/frame on jacks and closely observe the driveline/tranny while someone shifts? But do chain or tie it down in case it hops the jacks, and leave yourself survival space underneath!
gutthans is offline  
post #13 of 40 Old 03-12-2019, 03:07 PM
TheBoogieman
Disturbed Jeepaholic
 
TheBoogieman's Avatar
2003 TJ Wrangler 
 
Join Date: Aug 2006
Location: CharlottesHELL
Posts: 38,116
Quote:
Originally Posted by soyjer View Post
https://www.naxja.org/forum/showthread.php?t=1146705

I appreciate your help. Unfortunately, because I have no other XJ's around to compare to, I am having to rely on professionals and forums to tell me what is normal for an XJ. All of them agree that my clunk/lurch is abnormal and damaging, and not anything other than the transmission, and yet extensive transmission work and analysis finds nothing. I even bought my own line pressure gauge, just to make sure that it isn't a line pressure problem...desperation.
The best clue to the source of the problem is that if I shift to reverse before drive, especially when cold, then sometimes it won't clunk. It NEVER clunks into reverse, btw. Idle is 730rpm.
Mine has been doing the same thing since I bought it 30,000 miles ago. I stopped worrying about it 20,000 miles ago.
downs likes this.

Quote:
Originally Posted by jeepinmichguy_ View Post
TheBoogieman is a jerk.
03' Rubicon/Zone 4.25" combo lift/Rancho 9000XL shocks/5.13 gears-35" MTZs/LoD bumpers/Black Magic brakes
Desert Sand 99' XJ Classic (JEEP #18) ) 5" BDS lift / HP30/ 8.25/ 33x12.50" DC Extreme Country/Tactik black satin wheels.
TheBoogieman is offline  
post #14 of 40 Old 03-12-2019, 03:50 PM
CJ7-Tim
Real Jeeps have dents
 
CJ7-Tim's Avatar
2000 XJ Cherokee 
 
Join Date: Apr 2002
Location: out in the garage - Minneapolis
Posts: 26,975
My 1998 XJ has +284,000 miles on the original axles and transmission. It clunks. Pausing in NEUTRAL for about 15 seconds when shifting between Forward and Reverse reduces the clunking. I suppose that the pause allows the one or both of the following; the idle to drop slightly and/or the transmission internal pressure to drop slightly.

Pausing or not, and regardless of the idle speeds, I don't really worry about any of my current 3 Cherokees having AW-4 transmission issues. I jump in, start up, and drive off, below zero temps or above zero. The AW-4 is well known to be sturdy and extremely long lasting transmission if you use the Service Manual specified Dexron-III/Mercon fluid and change it regularly.

The XJ unibody transmits noises very well, and any mileage/age related wear in the drive-line, engine/trans mounts, or differential that creates noises, is amplified.
TheBoogieman and downs like this.

.

A recent Gallup public opinion poll shows the NRA, at 58% approval, has a higher approval rating than either Hillary Clinton or Barack Obama.

Progressive Liberalism: Bringing you new Healthcare ideas so wonderful, they have to include mandatory participation ...

Originally Posted by Ronald W. Reagan: Government is not the solution to our problems; Government is the problem.
CJ7-Tim is offline  
post #15 of 40 Old 03-12-2019, 06:07 PM
downs
Member
 
downs's Avatar
1995 XJ Cherokee 
 
Join Date: Oct 2018
Location: Hunt County
Posts: 314
Garage
I hope you didn't have the trans rebuilt just because of the clunk. Trans rebuilds/remans don't have a stellar track record. Something like 33 percent of reman transmissions fail within a year or some crazy number like that.
TheBoogieman likes this.

1995 Jeep Cherokee Country 4X4 Stock
AW4/NP231/C8.25/D30/"UpCounty" suspension
downs is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
Higher Output Alternator tjohnathon ZJ Grand Cherokee Forum 23 12-16-2018 03:54 PM
Long Warm Up Times - caused by rusted plate where heat tube mounts to intake manifold PottsyCJ5 Jeep CJ Forum 21 10-02-2018 06:57 PM
Path Forward: To Long Arm or Not with 3" Lift Oktavius WJ Grand Cherokee Forum 7 06-21-2018 09:16 AM
Warm, smelly rear end. '04 WJ Mattyjm WJ Grand Cherokee Forum 13 03-27-2018 12:13 AM
Short Arm vs Long Arm NewJeeperYJ90 Wrangler General Discussion 13 03-17-2018 12:59 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome