4.0 valve tap - JeepForum.com

 
LinkBack Thread Tools
post #1 of 14 Old 05-28-2007, 08:39 PM Thread Starter
Tomguy
Registered User
2014 WK 
 
Join Date: Jul 2002
Location: Scranton, PA, USA
Posts: 195
4.0 valve tap

So my 4.0 has seemingly out of nowhere developed a rather loud valve tap. I didn't notice it before (maybe because I have the windows up in the winter?) but here's the lowdown:

It seems to be the #4 intake (as best as I can guess). I didn't notice it in the winter when I was running 5w30. When I recently changed the oil (10w40 hi mileage) I didnt notice the tapping right away but maybe a week after (of course, I don't drive the Jeep that much).
The engine has 170k on it, and used 1qt of oil in the last 3000 miles (when using 5w30). I have put Mobil 1 in it the last few times.

It's quite harsh when "cold" (first started - but at 75+, it's hardly cold). It almost vanishes when warmed - so maybe the oil's too thick? I know that 170k isnt that high for a 4.0, so what can I do to ensure longer engine life? Should I grab a head (and maybe cam) off one in the junkyard and redo it, then put that on to replace mine? And if I do - what kind of head will fit? Any head from a H.O. 4.0? Or only ones in a certain year range... my engine is a '92. I'd like to get another 30k or more out of it! Even though my body may not last that long...



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Hemi, Towing & Lux

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
198k
Previous: 1972 Benz 280SE 4.5, 1992 XJ Cherokee Laredo, 2006 Charger R/T
Tomguy is offline  
Sponsored Links
Advertisement
 
post #2 of 14 Old 05-29-2007, 01:09 AM
KamekLocked
Registered User
 
KamekLocked's Avatar
1999 XJ Cherokee 
 
Join Date: Jan 2007
Location: SK, Canada
Posts: 537
If your going to start rebuilding parts of the engine you should rebuild it all. Other wise you end up with a rebuilt cylinder head (top end) and a bottom end with 170k on it.

The engine is already consuming oil so after a valve job, and having the cylinder head rebiult you will have increased oil consumption due to the higher compression ratio and higher vacuum the engine would have. This then allows more oil to be sucked past the worn piston rigns...

Do you mean the lifter is noisey???

1999 Jeep Cherokee SE l 4.0 HO l AW4 l NP231
Dana 30/Chrysler 8.25 l 31x10.5x15 Wrangler MT/R
Flowmaster Delta 40 w/stock pipes
Optima Yellow Top l Custom Headlight Harness
Alpine CDA-9886
KamekLocked is offline  
post #3 of 14 Old 05-29-2007, 02:12 AM
88_xj_hunter
Registered User
1988 XJ Cherokee 
 
Join Date: Feb 2007
Location: Possum Kingdom
Posts: 203
It may just be collapsed valve lifter (hydraulic check valve inside lifter body that keeps pushrod cushioned). If that is the case, then you will have to pull the head and then you can use a lifter removal tool to reach into the block and pull the lifters off the camshaft. Replace them all while you are in there since they're only about $3 each for stock (12 in all). A collapsed lifter will keep a valve from opening fully but does become less noisy as the engines warms and the oil thins out. A worn out camshaft will also give these symptoms. If that's the case, rebuild.

'89 XJ Laredo 4.0L, AW4, NP242, Dana 30, 35 w/Lock Right, 5.5" lift, 35x12.50x15 Uniroyal m/t
'88 XJ 4.0L, AW4, NP231, Dana 30, 35 w/Lock Right, 4.5" lift, 31x9.50 SuperSwamper on salvaged 15x7's
'87 XJ Pioneer 4.0L, AW4, NP231, Dana 30, 35 w/ trac-loc, currently stock, 8" lift one piece at a time

Quote:
Originally Posted by mdonohu1
i sweat your nuts. badly.
88_xj_hunter is offline  
post #4 of 14 Old 05-29-2007, 02:48 AM
Merovingian
Registered User
 
Join Date: Apr 2007
Location: SC
Posts: 4
My '97 Cherokee Country has this same noise. A mech friend of mine listened to it and suggested Marvel Mystery Oil might help. What do you guys think? BTW, this is a daily driver that I don't plan to do any major engine work to. I only need to get 3-4 more years out of her then trade.
Merovingian is offline  
post #5 of 14 Old 05-29-2007, 01:02 PM
jv3kxj
Registered User
 
Join Date: Feb 2006
Location: northern Wisconsin
Posts: 255
You could also be hearing piston slap. It sounds a whole lot like valve train noise, and it goes away when it warms up. Lots of older Xj's have this noise, and it doesn't seem to have much effect on longevity. My 94 makes this noise, it has over 170k on it, and barely uses any oil between changes.

Signature
jv3kxj is offline  
post #6 of 14 Old 05-29-2007, 09:24 PM
Merovingian
Registered User
 
Join Date: Apr 2007
Location: SC
Posts: 4
Thanks jv, I feel better now.
Merovingian is offline  
post #7 of 14 Old 05-30-2007, 08:36 AM
bee guz
Registered User
 
Join Date: Jun 2006
Location: wilkes-barre Pa.
Posts: 1,119
sometimes a small peice of drbris gets in the lifter, I had this problem on newer chrysler prouducts in the seventys, I changed the oil ( because the oil was wooped) and let it get good and warm, and then rev it quick almost full throttel, don't go too nuts, this will float the lifters the engine will stumble a little run a little rough for a few seconds, and then repump the lifters.

They used to take the cars back to the dealer and do a one lifter change, so they said, after I started doing this thats all they did afterwards.

I worked for Avis, and the chrysler newports with the 383's were big on this, saved the company a lot of money, I of couse got nothing....
bee guz is offline  
post #8 of 14 Old 05-30-2007, 09:15 AM
XJH-007
Registered User
 
XJH-007's Avatar
 
Join Date: Mar 2005
Location: Morrison
Posts: 4,690
Quote:
Originally Posted by 88_xj_hunter
It may just be collapsed valve lifter (hydraulic check valve inside lifter body that keeps pushrod cushioned). If that is the case, then you will have to pull the head and then you can use a lifter removal tool to reach into the block and pull the lifters off the camshaft. Replace them all while you are in there since they're only about $3 each for stock (12 in all). A collapsed lifter will keep a valve from opening fully but does become less noisy as the engines warms and the oil thins out. A worn out camshaft will also give these symptoms. If that's the case, rebuild.

BINGO

I've had two 4.0's and a 4.2 do this. It's an easy fix but will consume an entire weekend.

*Pull the head and remove the valves, de-carbon everything and Lap the valves with lapping compound (cheap and easy) This will re-seat your valves and get rid of any pitting while increasing compression.

*Buy a "top end gasket kit" from your local parts store instead of buying the head gasket and manifold gaskets seperatly..this will save you a ton of cash. This kit also come with new valve guide seals

* swap out the lifters, re-using your push-rods.....

Essentially you've just done a minor rebuild on the head. Unless there's damage to the valve guides you do not need to have them re-cut. Sometimes having the valves re-cut and not the pistons/rings is worse then not doing anything for blowby.

Nothing like a quiet running 4.0

Scott-Crawlorado Native
I have an addiction.....
*00' XJ_T-n-T Y-Link/6" RE_OME's_33" KM2's
Tera 4:1 / 4:56's_Elec. Locked D44
**84' CJ7 4"BDS 33's
***02 WJ Overland
XJH-007 is offline  
post #9 of 14 Old 05-31-2007, 09:32 AM Thread Starter
Tomguy
Registered User
2014 WK 
 
Join Date: Jul 2002
Location: Scranton, PA, USA
Posts: 195
Quote:
Originally Posted by XJH-007
Nothing like a quiet running 4.0
There is such a thing?
My manifold's been cracked about 5 years now!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Hemi, Towing & Lux

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
198k
Previous: 1972 Benz 280SE 4.5, 1992 XJ Cherokee Laredo, 2006 Charger R/T
Tomguy is offline  
post #10 of 14 Old 05-31-2007, 09:34 AM
XJH-007
Registered User
 
XJH-007's Avatar
 
Join Date: Mar 2005
Location: Morrison
Posts: 4,690
Quote:
Originally Posted by Tomguy
There is such a thing?
My manifold's been cracked about 5 years now!

hahahahha....

Ebay, $65 to your door. It's a great time to change it!


Scott-Crawlorado Native
I have an addiction.....
*00' XJ_T-n-T Y-Link/6" RE_OME's_33" KM2's
Tera 4:1 / 4:56's_Elec. Locked D44
**84' CJ7 4"BDS 33's
***02 WJ Overland
XJH-007 is offline  
post #11 of 14 Old 05-31-2007, 12:53 PM
1990BlueXJ
Registered User
1990 FSJ Cherokee 
 
Join Date: May 2007
Location: Deep South TEXAS
Posts: 19
Quote:
Originally Posted by XJH-007
hahahahha....

Ebay, $65 to your door. It's a great time to change it!


Give us that Ebay link, cause I can't find it on Ebay that cheap.
1990BlueXJ is offline  
post #12 of 14 Old 06-02-2007, 12:22 PM Thread Starter
Tomguy
Registered User
2014 WK 
 
Join Date: Jul 2002
Location: Scranton, PA, USA
Posts: 195
Yeah, if you can tell me where to find a quality new manifold for $65 wiith shipping, I'd jump on it. Talk about a weekend project! Maybe I can get a can of R12 with it somewhere. I haven't recharged my AC (ever) and it's a little weak I think.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Hemi, Towing & Lux

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
198k
Previous: 1972 Benz 280SE 4.5, 1992 XJ Cherokee Laredo, 2006 Charger R/T
Tomguy is offline  
post #13 of 14 Old 06-02-2007, 03:31 PM
n20jeep
Web Wheeler
 
n20jeep's Avatar
1993 XJ Cherokee 
 
Join Date: Feb 2005
Location: J-Ville,FL
Posts: 2,359
Quote:
Originally Posted by Tomguy
Yeah, if you can tell me where to find a quality new manifold for $65 wiith shipping, I'd jump on it. Talk about a weekend project! Maybe I can get a can of R12 with it somewhere. I haven't recharged my AC (ever) and it's a little weak I think.
skip the R12 and covert your system, it WILL be ALOT cheaper than recharging with R12
n20jeep is offline  
post #14 of 14 Old 06-02-2007, 06:27 PM Thread Starter
Tomguy
Registered User
2014 WK 
 
Join Date: Jul 2002
Location: Scranton, PA, USA
Posts: 195
I don't see how a $25 can of R12 is more expensive than several bottles of R134a and the time and effort to change the dryer, and flush the system, and then have reduced capacity...


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Hemi, Towing & Lux

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
198k
Previous: 1972 Benz 280SE 4.5, 1992 XJ Cherokee Laredo, 2006 Charger R/T
Tomguy is offline  
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.



Email Address:
OR

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.




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



Similar Threads
Thread Thread Starter Jeep Forums Replies Last Post
PCV/other valve on valve cover leaking CJ7RX7 XJ Cherokee Technical Forum 10 04-12-2010 01:18 AM
EGR Valve XAMX XJ Cherokee Technical Forum 1 06-24-2009 03:50 PM
How do I remove ccv valve from valve cover ExJ XJ Cherokee Technical Forum 5 01-21-2009 09:40 PM
Valve stem seals? or valve lash? Godchsr XJ Cherokee Technical Forum 9 11-29-2007 02:28 PM
Coolant Mixing Valve / Heater Valve Leaking - Tips needed JWeb_93YJ XJ Cherokee Technical Forum 5 03-13-2005 08:34 AM

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