Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK2 - > Engine Performance/Intakes/Exhausts

Join Jeep Garage Today
Reply
 
Thread Tools Display Modes
 
  #1  
Old 03-27-2011, 12:00 AM
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Mar 2011
Location: Bay Area, CA
Posts: 106
Thanks: 6
Thanked 1 Time in 1 Post
Rep Power: 1402
K9jackie is on a distinguished road
Question What's The Best Way To Break-In the Hemi ??

What's The Best Way To Break-In the Hemi ?? I have only driven 40 easy miles... just 2 miles on the freeway but I plan to take it out for a spin tomorrow. Should I run it hard or easy? For how many miles?

The dealer didn't put any gas in my jeep, so I took it to costco and accidentally filled it with 87 instead of plus or premium. Will that effect the break in?

Sorry if this is a repost. I'm sure someone must have asked this but the search is not coming up with anything.


Thanks
Jackie
__________________

__________________
2011 Black Jeep Grand Cherokee Overland Summit Edition- 4x4 5.7L
2006 Red Jeep Wrangler Rubicon - 4x4 4.0L


http://twitter.com/#!/lemon
Reply With Quote
  #2  
Old 03-27-2011, 12:18 AM
Dan JGC's Avatar
Premium Member
 
Join Date: Dec 2010
Posts: 2,006
Thanks: 3
Thanked 72 Times in 59 Posts
Rep Power: 4373
Dan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond repute
Re: What's The Best Way To Break-In the Hemi ??

Best to use 89 instead of 87....for best performance. I was told to NOT use above 89 since it burns hotter (that's what the dealer said).

I have about 240 miles on mine. I did put Interstate miles on mine at first and I picked it up at 5 miles on the odometer. I suppose I could have avoided the Interstate and taken other roads. Filled it up with mid-grade 89 which is what I will use.

Someone had posted...or maybe it was Jeep...about the first 50 miles to be gentle. I was told by the dealer not to pull the full towing of 7000+ lb for something like the first 2K miles...something about the breaks breaking in....dunno, I don't tow so didn't pay attention to remember.
__________________

__________________
•|||||||• 2014 Jeep Grand Cherokee Summit 4x4 V8 in Bright White Clear Coat exterior with Grand Canyon Jeep Brown interior. •|||||||•
Reply With Quote
  #3  
Old 03-27-2011, 12:20 AM
Dan JGC's Avatar
Premium Member
 
Join Date: Dec 2010
Posts: 2,006
Thanks: 3
Thanked 72 Times in 59 Posts
Rep Power: 4373
Dan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond repute
Re: What's The Best Way To Break-In the Hemi ??

BTW....don't ya just love your Black Summit??? Mine is fantastic and lovin' it!
__________________
•|||||||• 2014 Jeep Grand Cherokee Summit 4x4 V8 in Bright White Clear Coat exterior with Grand Canyon Jeep Brown interior. •|||||||•
Reply With Quote
  #4  
Old 03-27-2011, 12:42 AM
JP49's Avatar
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Feb 2011
Location: WA State
Posts: 41
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1366
JP49 is on a distinguished road
Re: What's The Best Way To Break-In the Hemi ??

The dealer maintenance sup. told me to do the first oil change at 2500 miles, because they use a special oil mix for breaking in the engine. He also said synthetic oil is ok but change every 10,000 miles. That is his comments to me. I had no idea. I forgot to ask in my old age about how often the filter should be changed if using synthetic oil... Any one else know something different?
__________________
Reply With Quote
  #5  
Old 03-27-2011, 12:54 AM
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Mar 2011
Location: Bay Area, CA
Posts: 106
Thanks: 6
Thanked 1 Time in 1 Post
Rep Power: 1402
K9jackie is on a distinguished road
Re: What's The Best Way To Break-In the Hemi ??

Quote:
Originally Posted by Dan JGC View Post
BTW....don't ya just love your Black Summit??? Mine is fantastic and lovin' it!

Um, yeah . I really love it... It is the coolest car I have owned so far! It is much better than the BMW X5 I had. Love that the summit has all the gadgets too... It was fun learning how they worked today. The interior is heaven...can't really say enough about it. My friends and neighbors were drooling... They all want one too. Go jeep & USA
__________________
2011 Black Jeep Grand Cherokee Overland Summit Edition- 4x4 5.7L
2006 Red Jeep Wrangler Rubicon - 4x4 4.0L


http://twitter.com/#!/lemon
Reply With Quote
  #6  
Old 03-27-2011, 08:32 AM
Premium Member
My Jeep: 2012 6.4L SRT8
 
Join Date: Dec 2010
Location: Ormond Beach FL
Posts: 1,544
Thanks: 0
Thanked 22 Times in 21 Posts
Rep Power: 2945
mjw930 has a reputation beyond reputemjw930 has a reputation beyond repute
Re: What's The Best Way To Break-In the Hemi ??

The key to breaking in the motor is to keep it from developing hot spots, that's best accomplished by varying the RPMs and driving conditions hence the typical comments to not maintain any one speed for too long. Being "good" to the motor for the first 50 miles is always a good idea, both for the motor and the rest of the drivetrain. From there I would basically drive it as you normally would with the exception of this tidbit that comes from the Owners Manual:

Quote:
ENGINE BREAK-IN RECOMMENDATIONS
A long break-in period is not required for the engine and
drivetrain (transmission and axle) in your vehicle.
Drive moderately during the first 300 miles (500 km).
After the initial 60 miles (100 km), speeds up to 50 or
55 mph (80 or 90 km/h) are desirable.

While cruising, brief full-throttle acceleration within the
limits of local traffic laws, contributes to a good break-in.
Wide-open throttle acceleration in low gear can be detrimental
and should be avoided.


The engine oil installed in the engine at the factory is a
high-quality energy conserving type lubricant. Oil
changes should be consistent with anticipated climate
conditions under which vehicle operations will occur. For
the recommended viscosity and quality grades refer to
“Maintenance Procedures” in “Maintaining Your Vehicle”.
NON-DETERGENT OR STRAIGHT MINERAL
OILS MUST NEVER BE USED.

A new engine may consume some oil during its first few
thousand miles (kilometers) of operation. This should be
considered a normal part of the break-in and not interpreted
as an indication of difficulty.
That section seems to confirm the long held belief by many who have built performance engines that proper seating of the rings is best achieved by WOT Acceleration and Deceleration to apply equal upward and downward pressure on the rings. It's interesting (and welcome) to see it in print from a major engine manufacturer.

Since I plan on pulling a 5000 lb load before I reach the 2000 mile mark (probably around 1000 miles on the clock) I changed to 100% synthetic oil with a new filter @ 650 miles. Aside from that I've been driving it as normal and it's been running in quite nicely.
__________________
2012 Grand Cherokee SRT8 Black/Black
Reply With Quote
  #7  
Old 03-27-2011, 09:32 AM
Dan JGC's Avatar
Premium Member
 
Join Date: Dec 2010
Posts: 2,006
Thanks: 3
Thanked 72 Times in 59 Posts
Rep Power: 4373
Dan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond repute
Re: What's The Best Way To Break-In the Hemi ??

^^^ Thanks for posting the quote. I did drive on the Interstate after 10....didn't gun it though....so was reasonably gentle...but the thing did want to cruise easily over 60 to 70.

One thing it does not say is whether WOT should be done within the first 300 miles...it is ambiguous as to when this should be done.
__________________
•|||||||• 2014 Jeep Grand Cherokee Summit 4x4 V8 in Bright White Clear Coat exterior with Grand Canyon Jeep Brown interior. •|||||||•
Reply With Quote
  #8  
Old 03-27-2011, 09:50 AM
Premium Member
 
Join Date: Oct 2010
Posts: 227
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 1681
Jpjr is on a distinguished road
Re: What's The Best Way To Break-In the Hemi ??

Quote:
Originally Posted by Dan JGC View Post
Best to use 89 instead of 87....for best performance. I was told to NOT use above 89 since it burns hotter (that's what the dealer said).

I have about 240 miles on mine. I did put Interstate miles on mine at first and I picked it up at 5 miles on the odometer. I suppose I could have avoided the Interstate and taken other roads. Filled it up with mid-grade 89 which is what I will use.

Someone had posted...or maybe it was Jeep...about the first 50 miles to be gentle. I was told by the dealer not to pull the full towing of 7000+ lb for something like the first 2K miles...something about the breaks breaking in....dunno, I don't tow so didn't pay attention to remember.

The HEMI motor was tuned this time around to run on regular (i.e., 87 octane gas), sheerly for cost savings. Ideally when you buy a HEMI you buy it for power, and your dealer is right the higher octane gas burns "hotter". Without getting into details he means that the ignition temp of 91 octane gas is higher than 87 octane gas, allowing the engine's computer to add timing and boost the power stroke of the motor. Stated differently, since the ignition temp is higher the chance of detonation (i.e., gas exploding prematurely and damaging the motor rather than pushing the piston) is lower so the motor can safely make more power.

I continue to fill my HEMI with premium gas for power as I did with my '08.. but unlike a few years ago you can fill most V8 engines with regular gas (vs premium only) today as well. My CTS-V still requires premium however as do almost all higher compression motors.
__________________
Reply With Quote
  #9  
Old 03-27-2011, 10:15 AM
Dan JGC's Avatar
Premium Member
 
Join Date: Dec 2010
Posts: 2,006
Thanks: 3
Thanked 72 Times in 59 Posts
Rep Power: 4373
Dan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond reputeDan JGC has a reputation beyond repute
Re: What's The Best Way To Break-In the Hemi ??

Doesn't the manual say use 89, but 87 is "acceptable". It says nothing about 91.
__________________
•|||||||• 2014 Jeep Grand Cherokee Summit 4x4 V8 in Bright White Clear Coat exterior with Grand Canyon Jeep Brown interior. •|||||||•
Reply With Quote
  #10  
Old 03-27-2011, 11:24 AM
GTOGreg's Avatar
Member
 
Join Date: Feb 2011
Posts: 205
Thanks: 0
Thanked 3 Times in 1 Post
Rep Power: 1531
GTOGreg has a spectacular aura about
Re: What's The Best Way To Break-In the Hemi ??

vary RPM as was already said and you're good. Oil change at 2500 is a good idea. Otherwise, drive it how you normally would.
__________________
-------
2011 Hemi WK2 Blk/Blk
Offroad I, Mopar Rock Rails, Mopar roof racks, Tow, Nav, Lockpick v.2, Sharkfin, Thule 1800XT cargo box, RRO front leveling kit, Firestone Destination ATs
Reply With Quote
  #11  
Old 03-27-2011, 11:25 AM
Member
My Jeep: 2011 5.7L WK2
 
Join Date: Jul 2010
Location: Los Angeles, CA
Posts: 78
Thanks: 3
Thanked 2 Times in 2 Posts
Rep Power: 1600
slampert is on a distinguished road
Re: What's The Best Way To Break-In the Hemi ??

Dan--you've got to take a nice long cruise down to Key West and get that truck broken in !

While there appears to be a solid consensus concerning the use of 89 fuel, I don't understand why there is so much debate on recommended motor oil for the 5.7.

When I suggested changing over to synthetic my dealer / service manager replied with an emphatic "Don't !!"
__________________
Reply With Quote
  #12  
Old 03-27-2011, 12:21 PM
Sammzway's Avatar
Member
My Jeep: 2011 3.6L WK2
 
Join Date: Mar 2011
Location: BayShore NY
Posts: 194
Thanks: 6
Thanked 3 Times in 1 Post
Rep Power: 1474
Sammzway is on a distinguished road
Re: What's The Best Way To Break-In the Hemi ??

Hey guys, i've been reading back and forth around this thread about the entire break in process.

I just picked up a 3.6 Laredo X (I take delivery next week) and this is my 1st brand new vehicle. Any different direction to break in the 3.6 compared to the HEMI? I heard you drive normal without WOT for the first 500 miles. After that you can drive it however you want. Also, should I change oil after 2500 too or after 5000?

Sorry for the thread jacking.
__________________

__________________
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not 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 Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
5.7 Hemi Engine Break-In Oil Change Roaster Boy Tech Tips/DIY/How To 13 01-17-2012 10:22 PM
Break in period 1napili1 Tech Tips/DIY/How To 6 02-18-2011 01:30 PM
MDS V8 Break-in litespeedz Engine Performance/Intakes/Exhausts 11 12-24-2010 07:37 PM
Recommended Break-in Arnol Tech Tips/DIY/How To 2 11-24-2010 08:33 PM

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 12:46 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community