Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here! ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!

Break In

Old 09-06-2015, 09:20 AM
  #1  
Junior Member
Thread Starter
 
Join Date: Jul 2015
Location: Western NC
Posts: 36
Year: 2000 & 1997
Model: Grand Cherokee
Engine: 4.0
Default Break In

On Wednesday or Thursday, I hope to start my rebuilt engine for the first time. I just watched a video about Joe Gibbs break in oil. Anyone have any experience with this? It's only good for about 400 miles so it's relatively expensive. It's supposed to help break in the cam, as it has more zinc additive. So is it worth it or just use regular oil? By the way, it is called Driven now.
lpresnell is offline  
Old 09-06-2015, 03:04 PM
  #2  
CF Veteran
 
JPXJMOAB's Avatar
 
Join Date: Jan 2015
Location: Minnesota
Posts: 2,152
Year: 1999
Model: Cherokee
Engine: 4.0L
Default Break In

In my experience I'd just use regular oil on a break in. I would not want to use any additive, especially during a break in.
JPXJMOAB is offline  
Old 09-06-2015, 03:41 PM
  #3  
CF Veteran
 
dave1123's Avatar
 
Join Date: Nov 2010
Location: Manlius, east of Syracuse, NY
Posts: 11,045
Year: 2000
Model: Grand Cherokee (WJ)
Engine: 4.0L
Default

The break-in procedures have been a controversial subject since Ford built his first one! There are only 2 areas of major friction to be concerned about, the piston rings and the cam lobes. I've rebuilt many engines in my life and all I ever did was use a moly-d cam lube on assembly and idled the engine to normal temperature before putting any load on it. I haven't seen positive proof that the cam lube does anything special, so you can take that as questionable also.

My Chrysler Hemi was the most highly modified engine I ever built and that overheated in the first 15 minutes of running, at which time I shut it off and let it cool, then restarted and let it idle up to temp again. It was fine after that. I think that was the initial ring break-in. I used a standard 10W-30 oil and drove it normally for about 100 miles before attempting to wind it up. I changed the oil and cut open the filter to see if there was any metal in it. There wasn't, so I figured I had a good one. I took it to the strip after 250 miles, changing the oil before and after. The hardest part for me was trying to drive it NORMALLY for the first 250 miles. When you've got a monster motor under the hood, it's too tempting to stomp on it!

One thing I would suggest though is to disconnect the ignition and crank it over until you've got oil pressure before you fire it. Most of the bearing wear in ANY engine is on start-up before oil pressure comes up. JMHO, but use whatever oil you plan on using for the life of the engine.

Just the musings of a 70-year-old teenager.
dave1123 is offline  
Old 09-08-2015, 07:45 AM
  #4  
Senior Member
 
Join Date: Jan 2012
Posts: 952
Year: 2004
Model: Grand Cherokee
Engine: 2000 4.0
Default

No need for anything special. If you used assembly lube on everything your golden. If not just spin the oil pump for a minute to circulate oil everywhere.
bigbadon is offline  
Old 09-08-2015, 10:17 AM
  #5  
CF Veteran
 
JPXJMOAB's Avatar
 
Join Date: Jan 2015
Location: Minnesota
Posts: 2,152
Year: 1999
Model: Cherokee
Engine: 4.0L
Default Break In

You should have primed the oil pump before hand either way.
JPXJMOAB is offline  
Old 09-08-2015, 10:59 AM
  #6  
CF Veteran
 
Fred/N0AZZ's Avatar
 
Join Date: Jul 2013
Location: Monett, MO.
Posts: 7,554
Year: 1999
Model: Cherokee
Engine: 4.0
Default

Originally Posted by bigbadon View Post
No need for anything special. If you used assembly lube on everything your golden. If not just spin the oil pump for a minute to circulate oil everywhere.

Yup down through the distributor opening and spin that till I see at least 40 psi. Then close that puppy up and get it on the engine dyno.
Fred/N0AZZ is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
ROCKRIDGE 4WD
Vendor Showcase
6
07-13-2016 12:11 PM
DynoGuy
Jeep Builds
52
04-26-2016 04:55 AM
Raney120
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
22
10-16-2015 11:27 AM
redrooster
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
7
10-02-2015 12:35 AM
jpartier
Cherokee Chat
6
09-27-2015 09:42 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: Break In


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description: