ZJ Engine Refreshment - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > ZJ Engine Refreshment

Jeep Tweaks at JeepHutIntroducing MONSTALINER™ UV Permanent DIY Roll On Bed LineJeep speedometer gears at rockridge4wd

Reply
Unread 11-14-2013, 08:57 AM   #1
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Here's my clean 1995 GC limited 4.0 2wd with 270,000 miles.





In about a month I'm driving her from Michigan to Arizona while flat towing my YJ most of the way. I'll be the first to admit that's a pretty tall order for the 4.0 so I'm going to increase the odds of a successful trip.

First step was to test the compression. No point in putting money into a bad engine.





Considering how many miles, the engine tested pretty good.

Dry 110 100 100 95 100 100
Wet 140 120 125 125 140 140

I think cylinders 2,3,4 tested lower because of the head gasket leak.

The zj is in great condition all around with only a few concerns.

Tasks

Replace Head gasket
Replace Oil pump



While doing that I plan on replacing t stat, valve cover gasket, manifold gasket, injector o rings, and clean the rear diff. Everything else, plugs, wires, cap, rotor, water pump, trans, are all new or in good shape.

On to the fun! Tore everything apart. Head studs where kind of rusty so I let them sit in PB for a few hours. Last thing I need is for bolt to break of in the block.





After a few hours, head bolts came out fine :-)





ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 09:01 AM   #2
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Just took the head to get cleaned and milled. Should be done on Monday :-)
ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 09:10 AM   #3
WJ4x4LIFE
Registered User
 
Join Date: Sep 2012
Posts: 574
A couple of questions out the gate.

1.) What did you pay for it?
2.) Why a 4.0L, not a V8? two-part question, was is a kinda of first come first serve (with known HG issue) or a preference?
3.) Why a 2wd model, again preference or reason?

Sorry, to bomb you with ?'s, but I like some context background to enjoy the story and build! I wish you the best of luck in your trip!
WJ4x4LIFE is offline   Reply With Quote Quick reply to this message
Unread 11-14-2013, 09:14 AM   #4
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Quote:
Originally Posted by WJ4x4LIFE View Post
A couple of questions out the gate.

1.) What did you pay for it?
2.) Why a 4.0L, not a V8? two-part question, was is a kinda of first come first serve (with known HG issue) or a preference?
3.) Why a 2wd model, again preference or reason?

Sorry, to bomb you with ?'s, but I like some context background to enjoy the story and build! I wish you the best of luck in your trip!
It's not a new to me Jeep. I've had it for around 4 years and had been in the family it's whole life spending most of it in California and Arizona. I received it for free so I didn't complain about it not bring 4wd. Plus, the YJ is more enjoyable offroading.
ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:07 AM   #5
xcaliber81
Registered User
1994 ZJ 
 
Join Date: Jul 2012
Location: Prince George, B.C
Posts: 3,016
How did you do the compression test? I did one but after I was told I did it wrong.
xcaliber81 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:19 AM   #6
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Quote:
Originally Posted by xcaliber81 View Post
How did you do the compression test? I did one but after I was told I did it wrong.
It pretty simple.

1.Disconnect ignition

2.Remove spark plugs one at a time whole testing each cylinder with the compression gage

3.Screw gage inlet into the spark plug port.

4.turn the engine over a few times. The gage should make 4-6 big jumps and then slow down dramatically. Stop when this happens. This will be you dry test number.

5.Then remove gage and poor in a small amount of oil into the cylinder. Just enough to coat the cylinder head.

6.Repeat step four on the same cylinder. This well be your wet test.

7. Do this to all 6 cylinders resulting in 12 numbers. All dry numbers should be similar and all wet numbers should be similar.
ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:21 AM   #7
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Quote:
Originally Posted by ashland82391 View Post

It pretty simple.

1.Disconnect ignition

2.Remove spark plugs one at a time whole testing each cylinder with the compression gage

3.Screw gage inlet into the spark plug port.

4.turn the engine over a few times. The gage should make 4-6 big jumps and then slow down dramatically. Stop when this happens. This will be you dry test number.

5.Then remove gage and poor in a small amount of oil into the cylinder. Just enough to coat the cylinder head.

6.Repeat step four on the same cylinder. This well be your wet test.

7. Do this to all 6 cylinders resulting in 12 numbers. All dry numbers should be similar and all wet numbers should be similar.
Here's a good video that will better help you.

https://www.youtube.com/watch?v=X_tb...e_gdata_player
ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:27 AM   #8
xcaliber81
Registered User
1994 ZJ 
 
Join Date: Jul 2012
Location: Prince George, B.C
Posts: 3,016
i did not remove my spark plugs nor did i disable the ignition which resulted in 60 psi per cylinder. I also did that when i first bought it and i doubt my jeep has a 60 psi per cylinder engine lol.
xcaliber81 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:32 AM   #9
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Quote:
Originally Posted by xcaliber81 View Post
i did not remove my spark plugs nor did i disable the ignition which resulted in 60 psi per cylinder. I also did that when i first bought it and i doubt my jeep has a 60 psi per cylinder engine lol.
?? How in the world did you test it with the spark plug in lol. Yeah, 60 is a pretty much shot engine.
ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:36 AM   #10
xcaliber81
Registered User
1994 ZJ 
 
Join Date: Jul 2012
Location: Prince George, B.C
Posts: 3,016
took out 1 plug at a time and started the engine ran for 5 or so seconds. everywhere else i have been reading said to remove all plugs and wires disable the fuel and ignition and crank for 5 seconds, so pretty much what you said.
xcaliber81 is offline   Reply With Quote Quick reply to this message
Unread 11-14-2013, 10:44 AM   #11
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Quote:
Originally Posted by xcaliber81 View Post
took out 1 plug at a time and started the engine ran for 5 or so seconds. everywhere else i have been reading said to remove all plugs and wires disable the fuel and ignition and crank for 5 seconds, so pretty much what you said.
Yeah, your not suppose to actually start the vehicle lol. Ya live a ya learn. You don't have to remove all the plugs at once though. Just pop off the write off the end of the plug then remove the plug and remove the center wire from the distributer cap. It connect to the the ignition.
ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-14-2013, 02:40 PM   #12
JohnCrabtree
Registered User
1994 ZJ 
 
Join Date: Mar 2013
Location: Sonora, California
Posts: 314
You're actually supposed to remove all plugs at once. If you have a leak in between cylinders and you crank it, your engine will pressurize both cylinders and read as pressurized. If you take all plugs out and have a leak between 2 cylinders then it will not hold pressure at all.

You can get a false positive by leaving plugs in. In other words, it can read good when it's bad.
JohnCrabtree is offline   Reply With Quote Quick reply to this message
Unread 11-15-2013, 04:20 AM   #13
ashland82391
Out of money yet...Yup!
 
ashland82391's Avatar
1993 YJ Wrangler 
 
Join Date: Sep 2011
Location: Chandler, Arizona
Posts: 6,510
Pulled the oil pan. Way more difficult on a stock vehicle as oppose to a lifted one lol.



Oil oil pump vs new



I also decided to do the rear main while I'm in there. I've heard how hard it is and how big a pain it it's to change but seriously it was cake...

ashland82391 is online now   Reply With Quote Quick reply to this message
Unread 11-15-2013, 10:43 AM   #14
xcaliber81
Registered User
1994 ZJ 
 
Join Date: Jul 2012
Location: Prince George, B.C
Posts: 3,016
its only a PITA if you tear it a bit and have to do it all over again.
xcaliber81 is offline   Reply With Quote Quick reply to this message
Unread 11-15-2013, 12:21 PM   #15
WJ4x4LIFE
Registered User
 
Join Date: Sep 2012
Posts: 574
Quote:
Originally Posted by ashland82391 View Post
It's not a new to me Jeep. I've had it for around 4 years and had been in the family it's whole life spending most of it in California and Arizona. I received it for free so I didn't complain about it not bring 4wd. Plus, the YJ is more enjoyable offroading.
Can't beat "FREE/given! "
WJ4x4LIFE is offline   Reply With Quote Quick reply to this message
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.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools






Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.