2006 4.0 TJ not "TUPY"? - JeepForum.com
LinkBack Thread Tools
post #1 of 3 Old 12-11-2013, 05:04 PM Thread Starter
Registered User
Join Date: Mar 2012
Location: Trelleborg
Posts: 59
2006 4.0 TJ not "TUPY"?

Got a great deal for a 2000 WJ with a knocking engine. It have only done 90k miles but it has the infamous 0331 head and the previous owner didn't notice that all the coolant got into the oil. He drove with it until it stalled and when it cooled of it started again but it knocked really bad. I bought it a year after it was put away and now the engine is stuck. I got 3-4 gallons of oil and water out of the sump and all the valves are stuck with rust, the engine is probably not worth to save, I'll have to see when I take of the oil pan.

I have read a lot about the "TUPY" head but all I find is that it is only used on the 02-04s. I have found a low milage 4.0 from a TJ made in 2006 that I would like to rebuild. The seller though says that it's got the 0331 head but he can't find the "TUPY" under the oil cap. Did these late engines have the reinforced head even though it doesn't say TUPY?

I don't like the idea of putting a regular 0331 head on a rebuilt engine.

I have found a -94 ZJ 4.0 engine with just 70k miles but it seems like a lot if work with the engine mounts, alternator bracket, idler pulley and exhaust manifold?

Help needed! Engines from these late jeep 4.0s are hard to find here in Sweden but there are hundredths of the old ones.

XJandZJ is offline  
Sponsored Links
post #2 of 3 Old 12-12-2013, 03:55 PM
Registered User
1993 ZJ 
Join Date: Apr 2010
Location: Oklahoma
Posts: 250
I think you will be fine with the later TJ engine regardless of whether or not it has TUPY cast in to the head. From what I understand, once the problem was identified, the early heads were not used. Being an '06 build, you should be safe. I picked up a 2001 WJ earlier this year that had the head fail as well. The #3 piston is broken and there is an audible rod knock at idle. The oil drained like thin chocolate pudding. Obviously this motor is done and not worth rebuilding. I had a running '95 XJ that I was going to use for a donor motor, but like you said, the conversion would be pretty significant. Instead, I am waiting for a used TJ engine in the '03-06 range to be available at the right price. -Joe
Purcell69 is offline  
post #3 of 3 Old 12-19-2013, 12:44 PM Thread Starter
Registered User
Join Date: Mar 2012
Location: Trelleborg
Posts: 59
I got the -06 TJ motor a few days ago and it looks like it's gonna fit just fine. Like you said, they should have fixed the problem on these late models. Does anyone know if I can see any differences on the heads now when I have removed the valve over on both of them?

I will write here when the swap is complete Joe. I thought it would be easy to find a good engine in USA?

I finally got the old engine out today, everything is rusted, I had to use a lot of heat at the bell housing bolts to break them loose. This is my first WJ and probably my last one. Everything takes way more time to remove or fix than it should. Even my 5.2 ZJ have more room under the hood. Why would someone put the AC compressor under the powersteering pump with steel tubes attached to it? On the XJs, ZJs and probably the early TJs it's on top of the engine and they used hoses. When I did the plenum gasket I just removed the compressor and put it away without draining the system? The grill is another thing, on the WJ I had to remove the entire front bumper since it's made together with the grill? And what about the black steel pieces supporting the transmission and engine? Why? When I go for another Jeep it will be pre -99
XJandZJ is offline  

Quick Reply

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


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

Email Address:


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.

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

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