'03 WJ 4.7L Engine Rebuild (NIGHTMARE) / Cam Swap / TB Bore - 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 > WJ Grand Cherokee Forum > '03 WJ 4.7L Engine Rebuild (NIGHTMARE) / Cam Swap / TB Bore

Black Friday Sale - Deep Discounts from ExtremeTerrain.com6th Annual, Beat Your Wife to the Credit Card Sale!FS: Wrangler RGB Multicolor Fog Light LEDs: Awesome Effect

Reply
Unread 04-26-2012, 01:37 PM   #1
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
Wj '03 WJ 4.7L Engine Rebuild (NIGHTMARE) / Cam Swap / TB Bore

Since the internet has been a great resource for most of the information I needed for this project, I figured I'd offer my experience to those out there like me, that decide to take on these crazy projects!!

I'm going to break this up a bit as it'll make it easier to read, and I have a lot of pictures. For those just looking for information/tutorials, or those not wanting to read my rambling, you can skip to the next post.

This is going to be an on-going post, because as you will see shortly, the re-build went from bad to worse, and I'm now on my second round...

(If you prefer, you can just skip Here to see the final result)

A little background:

I bought my 2003 WJ Limited 4.7L non-H.O. in 2008. Right from the start it had its share of problems. The battery died and wouldn't restart on the test drive (perhaps this was an omen!). Shortly after bringing it home, one morning it fired and immediately started running rough, and threw the check engine light. Turns out the left bank had thrown a cam follower. Over the next few weeks I would battle this issue, having it occur three more times (Link to Previous Post). Finally, after much hair pulling, the dealership rebuilt the left head under warranty.

At the same time, I was having overheating issues, and the dealership also replaced the water pump and thermostat. I began to believe this was all related, and that perhaps the previous owner had severely overheated the rig.

Fast forward a bit, to around 18 months ago. The Jeep started having cooling issues, was losing water, and when it was cold out, would "steam" out the exhaust for a bit. I did all the normal checks, (dye test, pressure test, compression test, etc) and had a trusted mechanic do the same. Verdict was, "somewhere" I had a small leak in the engine compartment, causing the water loss, and the intake is sucking in some water through the CAI filter causing the brief steam. I poured in a can of stop leak, hoping that A) the leak would get worse and allow me to actually locate it, or B) stop for the time being.

About a month ago, I decided to finally figure out what the issue was, as it's been nagging at me for quite some time. I performed a pressure test and a block test (exhaust gas test). I found I had a leak in the heater return hose, and exhaust gases in the coolant... This meant it was time for some drastic engine overhaul...

dsc03511.jpg  
65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 04-26-2012, 02:13 PM   #2
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
Exclamation Diagnosing the Problem

The Engine Block Test

For those who don't know, Autozone will "rent" tools. The way it works is you buy the tool at full price, but you get a 90 day no questions asked return policy. I actually returned the test fluid bottle, empty and received a full refund! The ring compressor I rented broke on the last piston, and I also received a full refund (didn't expect that).

So for the block test, I obviously rented the kit from AutoZone. It comes with a "test tube", suction bulb, and test fluid. The way it works is you pour a small amount of fluid into the tube, start the vehicle (it must be cold!) with the radiator cap off, and insert the rubber stopper into the radiator opening. The rubber bulb sucks the "air" out of your radiator and checks it for the presence of CO. BE SURE NOT TO SUCK IN ANTI-FREEZE, as that will ruin the test fluid and you have to start over.

Here is a picture of the fluid before the test.



If the test is positive, the fluid will change color and look like this.



That means that there are exhaust gases present in your coolant system. This is usually the sign of a blown head gasket, or cracked head. In my case, it was the latter.

Last edited by 65Mustangs; 04-26-2012 at 02:21 PM.. Reason: Fixed images
65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 04-26-2012, 02:47 PM   #3
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
I decided to rebuild the motor on my own, trying to save a few bucks, and thinking it was something simple like a blown head gasket...

I attempted to remove the heads with the motor still in the rig. This was an idea I quickly abandoned... Though it's possible, you WILL bust a few knuckles, bleed, and swear. A LOT. The "easiest" way is to pull the motor, then disassemble.

In order to do this, the entire front of the Jeep must be removed...








To get to this point, it's taken me and a friend about 3 days work. The NUMBER 1 tip I can recommend, as you disassemble, use ziplock bags to organize and label your bolts for each component / step of the process!

Even with doing this, I still had trouble locating everything when it came time to reassemble...

Also, take your time. There are more wires, connections, bolted on ground wires, than one can imagine. If you miss a single one, it'll cause a headache trying to figure out what the motor is caught on, or worst case, you damage / destroy wiring, sensors, etc. costing you more time and $$$
65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 07:21 AM   #4
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
It's been a few days since I've posted, as I've been busy working on the Jeep. I'll continue with where I left off...

So after removing the front of the rig, disconnecting all the misc wires, grounds, hoses, etc. The motor is ready for removal.

Quote:
A word of advice:
When I pulled the motor, I left the torque converter connected to the flex-plate. The FSM says to remove the torque converter bolts, and leave it attached to the trans. This is a difficult feat. Instead - remove the trans and motor together as one unit, then uncouple when you have it on the ground. Also, reassemble this way, as it will keep you from damaging the input shaft on your trans. Something I found out the hard way...
With the motor removed, I was able to unbolt the heads and discover my problem... (that's antifreeze in the #4 cylinder...)

65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 09:08 AM   #5
roach68
Registered User
1999 WJ 
 
Join Date: May 2010
Location: french lick IN
Posts: 411
Do you plan on rebuilding just stock or throw some aftermarket parts in?
__________________
FOR SALE.
PAC SWI-Jack Steering wheel control interface-$35 shipped
roach68 is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 01:05 PM   #6
peytonimor7
Registered User
2004 WJ 
 
Join Date: Apr 2011
Location: Columbia, South Carolina
Posts: 1,063
Quote:
Originally Posted by roach68 View Post
Do you plan on rebuilding just stock or throw some aftermarket parts in?
X2 would like to know as well. Air Ram has some great aftermarket parts for rebuilds, depending on what you want to do.
__________________
l 04 WJ l OME HD+3/4" spacers l Bilstein 5100 l 245/70/17 Firestone M/Ts l IRO Adj. CAs F & R l
peytonimor7 is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 01:18 PM   #7
Bake1tEazy
Registered User
2001 WJ 
 
Join Date: Mar 2012
Location: Cottonwood Heights, UT
Posts: 49
Looks like a fun project hopefully it's smooth sailing now that you found the problem.
Bake1tEazy is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 01:30 PM   #8
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
Quote:
Originally Posted by Bake1tEazy View Post
Looks like a fun project hopefully it's smooth sailing now that you found the problem.
Funny you should say that... I'm actually on my second go 'round (I'll explain more later).

As for aftermarket parts, I installed a set of H.O. cams and bored the throttle body.
65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 01:37 PM   #9
metalhead
Registered User
2000 WJ 
 
Join Date: Nov 2008
Location: southampton, Pa
Posts: 998
This is a great post. Looking forward to reading it all.
metalhead is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 02:18 PM   #10
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
The parts...

After finding the problem, and breaking the motor open, I discovered that the water had started to "pit" the #4 and #6 cylinders. I decided to have the block machined 0.020" over to give me a fresh start.

The first step is removing the pistons from the block. To do this, the oil pan and lower girdle need to be removed. The connecting rods unbolt from the crankshaft. The rods on the 4.7L are a "split rod" or "cracked rod" meaning that the cap and rod are not machined, but cast as one piece and then broke apart. It may be a little shocking the first time you see this, but don't worry, it's supposed to look like that.





I purchased an entire rebuild kit from AirRam (http://www.airram.com/). Nick has been an awesome resource and much help.



The kit came with all the necessary bearings, seals, new pistons, rings, etc. I also ordered new head bolts, connecting rod bolts, and girdle bolts. The connecting rod bolts and girdle bolts are torque to yield design, so they MUST be replaced when doing a complete rebuild.

I had the machining done by Paolo Engine Service in Oregon City, OR. (http://www.paoloengine.com/). The bore was opened 0.020" the deck checked for flatness, and the whole mess was hot tanked to clean it throughly.

The next step was to press out the wrist pins, remove the old (smaller) pistons, and install the new pistons and wrist pins. I tried to heat shrink the wrist pins in, but it's a difficult process to do on your own at home. Luckily I have access to a hydraulic press at work, and I was able to finish the job there. If you are doing your own rebuild, I suggest you bring everything to your local machine shop and have them do it. I was quoted between $80 - $120.





Make sure that when you assemble (or have assembled) the pistons to connecting rods, you have everything facing the proper direction. The pistons I bought had an "F" cast onto the forward side, as well as an arrow marked on the piston face, to indicate which direction the piston was installed. The Connecting rod has an "oil slinger slot" which should also face the front of the motor.







For those who are observant, you will notice that the last picture, the connecting rod is installed backward. I screwed up on the very first one...
65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 02:37 PM   #11
peytonimor7
Registered User
2004 WJ 
 
Join Date: Apr 2011
Location: Columbia, South Carolina
Posts: 1,063
Already one step ahead with ordering Air Ram products!

Oh, and this is my obligatory "Where did you get HO cams??!?11" post.
__________________
l 04 WJ l OME HD+3/4" spacers l Bilstein 5100 l 245/70/17 Firestone M/Ts l IRO Adj. CAs F & R l
peytonimor7 is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 02:54 PM   #12
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
Installing the Pistons

Once you have the wrist pins and connecting rods installed, it's time to fit the rings. Unfortunately I didn't get any pictures when I did it, but I bought a ring file to do my sizing. I think it was $40 from Speedway.



To check the size and clearance of the rings, insert the piston without the rings into the cylinder bore. Take your first ring, and insert it into the bore, sitting flush on top of the piston. This will ensure that the ring is sitting perpendicular to the cylinder bore, and will give you the most accurate reading. Use a feeler gage to measure the gap in the ring. The gap is to be set as follows:

PISTON RINGS:
Ring Gap
Top Compression Ring 0.37 - 0.63 mm (0.0146 - 0.0249 in.)

Second Compression Ring 0.37 - 0.63 mm (0.0146 - 0.0249 in.)

Oil Control (Steel Rails) 0.25 - 0.76 mm (0.0099 - 0.30 in.)

It took me a few hours to size all the rings and install the rings onto the pistons. Take your time as one mistake here can make the difference in your motor burning oil and having weak compression, or making it a sweet, tight running machine!

After sizing all the rings, use a Ring Compressor to install the pistons into the block. I rented one from AutoZone. They are cheap, and you may be tempted to purchase your own, but the one I got from AutoZone failed on the very last piston. I had to use a hose clamp instead. Because I rented the tool, AutoZone took the broke piece back and gave me a full refund!!



Here is a neat link to some videos to walk you through the process. It was actually quite enjoyable to do. I find things like this tedious at times, but I enjoyed assembling the motor on my own.

http://wn.com/piston_rings



The block with all the pistons installed. This was a good day! It was exciting to see it going back together...

65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 03:08 PM   #13
kfxnando
Registered User
2001 WJ 
 
Join Date: Sep 2010
Location: Johannesburg South Africa
Posts: 725
subscribed

then would it be possible to add the price of spares
and what all was included in the kit that you got from air ram

self am on the other side of the Atlantic, and would be good to hear what it costs that side to rebuild these motors

thanx
look forward to following this thread
__________________
http://www.youtube.com/kfxnando

http://s538.photobucket.com/user/kfxnando/library/?sort=3&page=1
kfxnando is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 03:20 PM   #14
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
Quote:
Originally Posted by peytonimor7 View Post
Oh, and this is my obligatory "Where did you get HO cams??!?11" post.
Haha! yea... about that...

AirRam was out. I was tempted to call the stealership, but found a place online that had them in stock. FactoryChryslerParts.com

There was a little mishap, in that they only sent me one side. I called and talked to them, and they guy was pretty cool. Apologized and had the second cam shipped right away. From what I understand though, AirRam does have some in stock, or at least did a week ago. So if you're looking...
65Mustangs is offline   Reply With Quote Quick reply to this message
Unread 05-02-2012, 03:28 PM   #15
65Mustangs
Registered User
2003 WJ 
 
Join Date: Jan 2005
Location: Portland, OR
Posts: 131
Quote:
Originally Posted by kfxnando View Post
subscribed

then would it be possible to add the price of spares
and what all was included in the kit that you got from air ram

self am on the other side of the Atlantic, and would be good to hear what it costs that side to rebuild these motors

thanx
look forward to following this thread
The kit, plus the extra bolts, factory head gaskets, and factory exhaust gaskets, all from AirRam ran me about $1,200 USD. The inspection, machining, and cleaning was about $350 USD.

I'm in my build a whole lot deeper than that, but that's about what it would cost to do a basic rebuild (plus all your fluids, oil, antifreeze etc).
65Mustangs 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


Suggested Threads





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.