4.7 Dropped Valve Seat - YEAR POLL - Page 9 - JeepForum.com
View Poll Results: What year was your dropped valve 4.7?
1999 7 13.46%
2000 9 17.31%
2001 5 9.62%
2002 16 30.77%
2003 2 3.85%
2004 13 25.00%
Multiple Choice Poll. Voters: 52. You may not vote on this poll

 19Likes
Reply
 
LinkBack Thread Tools
post #121 of 132 Old 01-14-2020, 08:30 PM
Agent 000
Member
 
Agent 000's Avatar
2004 WJ 
 
Join Date: Mar 2006
Location: Canon City
Posts: 348
My '04 WJ experienced a dropped valve seat on cylinder number 2. Luckily, I opted to get a powertrain warranty when I bought the Jeep. The warranty company, after trying to cheap out and replace the engine (rather than having it rebuilt) with two other used engines, finally opted to get me a new re-manufactured long block engine.

Attached Thumbnails
20191125_132522.jpg   20191125_132557.jpg  

Bright Silver Metallic 2004 Jeep Grand Cherokee Limited
Agent 000 is offline  
Sponsored Links
Advertisement
 
post #122 of 132 Old 01-20-2020, 11:57 PM
WJ60
Registered User
 
WJ60's Avatar
2001 WJ 
 
Join Date: Oct 2019
Location: Pasco
Posts: 68
Garage
It would be interesting to see a poll of those who haven't had one drop.
Wizumz likes this.
WJ60 is offline  
post #123 of 132 Old 01-21-2020, 11:16 AM
Jimmy2Ton
Registered User
 
Join Date: Nov 2019
Posts: 14
agreed

agreed, we would be able to compare and determine the percentages of both failed and not.

What about including a mileage comparison? and or the factory where assembled (could be determined from VIN's)?

Would be nice to know if the failures are related to assembly plant, mileage, year mfg.... ect.
Jimmy2Ton is offline  
 
post #124 of 132 Old 01-21-2020, 07:07 PM
WJ60
Registered User
 
WJ60's Avatar
2001 WJ 
 
Join Date: Oct 2019
Location: Pasco
Posts: 68
Garage
With only 51 voting it would seem that the percentage is extremely low.
WJ60 is offline  
post #125 of 132 Old 01-22-2020, 06:56 AM
HarryH3
Registered User
2001 WJ 
 
Join Date: Jul 2015
Location: Planet Houston
Posts: 2,431
Quote:
Originally Posted by WJ60 View Post
With only 51 voting it would seem that the percentage is extremely low.
Keep in mind that less than 1% of WJ owners have ever even visited this site.
HarryH3 is offline  
post #126 of 132 Old 01-23-2020, 03:06 PM
Ylocuda
Registered User
 
Join Date: Apr 2018
Posts: 6
Keep in mind the people who find this site were driven here because they have the problem.
Ylocuda is offline  
post #127 of 132 Old 01-24-2020, 09:23 AM
WJ60
Registered User
 
WJ60's Avatar
2001 WJ 
 
Join Date: Oct 2019
Location: Pasco
Posts: 68
Garage
Quote:
Originally Posted by Ylocuda View Post
Keep in mind the people who find this site were driven here because they have the problem.


I wasn't driven here by a dropped valve, and apparently only 51 people were. According to forum stats there have been over 621,000 members on here, yet only 51 have posted they have had a d.v. I'm not here to troll, argue, or cause a debate. I'm strictly looking at the numbers. There are multitudes of replies in a multitude of posts that try to point the OP to a d. v. yet the numbers don't back that up. If someone could post factual numbers for all vehicles made with the 4.7l that have had a d.v. ,then I'll stop posting my thoughts and admit it's an issue, but we all know those numbers aren't out there. Numbers can justify whether or not there is truth in polls, statements, claims, etc, but these numbers are not supporting anything other than we have less than a .01% chance of have a valve drop. I'm sorry if my original response has gotten anyone worked up. It wasn't meant to do that. It was just a surprise to me that after having read all the various posts that indicate it's a very common problem, and then seeing a thread that has a poll attached to it addressing the issue, that after looking at the poll results I see 51 people who say they have had one. I got quite the chuckle out of it.
97Mule and Fzz like this.
WJ60 is offline  
post #128 of 132 Old 01-26-2020, 03:06 PM
Ylocuda
Registered User
 
Join Date: Apr 2018
Posts: 6
I don’t know the percentages as many are junked as soon as the issue happens or just not reported. I know of 3 just between me and a few friends. I do not think its a chronic issue but something that can very well happen. May be when the press fit of the seat meets the low end of the interference tolerance. In my case engine never overheated for a second and oil was changed with mobile 1 regularly. Happened after stopping by my doctor office to pick up xraysso it was a hot start. Only 145000 miles. Cost me $400 to fix it. Still running great today.
WJ60 likes this.
Ylocuda is offline  
post #129 of 132 Old 01-29-2020, 06:47 AM
Jimmy2Ton
Registered User
 
Join Date: Nov 2019
Posts: 14
Quote:
Originally Posted by WJ60 View Post
I wasn't driven here by a dropped valve, and apparently only 51 people were. According to forum stats there have been over <u>621,000</u> members on here, yet only 51 have posted they have had a d.v. I'm not here to troll, argue, or cause a debate. I'm strictly looking at the numbers. There are multitudes of replies in a multitude of posts that try to point the OP to a d. v. yet the numbers don't back that up. If someone could post factual numbers for <u>all</u> vehicles made with the 4.7l that have had a d.v. ,then I'll stop posting my thoughts and admit it's an issue, but we all know those numbers aren't out there. Numbers can justify whether or not there is truth in polls, statements, claims, etc, but these numbers are not supporting anything other than we have less than a .01% chance of have a valve drop. I'm sorry if my original response has gotten anyone worked up. It wasn't meant to do that. It was just a surprise to me that after having read all the various posts that indicate it's a very common problem, and then seeing a thread that has a poll attached to it addressing the issue, that after looking at the poll results I see 51 people who say they have had one. I got quite the chuckle out of it.
<br />
<br />

First, I think its important to consider the poll numbers more as anecdotal, rather than scientific when viewing them in a comprehensive manor. I have not looked at the numbers; however, the people that reported a D.V. are just that: the people that actually:

a) went online
b) found this site
c) registered
d) posted (either yes or no)

Clearly this is not representative of total numbers of D.V., nor could it be used to reflect a percentage; however I believe that the people who have been long time members, longtime mechanics, and socialize in such circles, are aware of a problem that others may not have identified as a common problem. I will cover perception later.

It is safe to assume that many people who had a similar problem, failed to do one or more of the following:

a) never went online
b) went online, but never came to this site
c) came to this site, but did not register
b) registered here but never posted in this thread

There is another variable that should include proper diagnosis. Many people may have been 'told' by a mechanic (or read online) that problem was a dropped valve seat, or assumed such themselves and junked, or sold vehicles. For a proper scientific study the head would need to be removed, and diagnosed by a qualified tech. Not difficult but necessary.

Now perception is a big deal actually. If your a pro tech in a shop, and 6 times a week you get jeeps of the same year/make/model all with bad wheel bearings, and you were asked about it, you would likely reply that those wheel bearings wear out on those XHSJSY jeeps really fast. But despite servicing over 250 wheel bearings on those pesky XHSJSY jeeps every year, that percentage may or may not represent an above average failure rate. Even the manufacturer only has dealership repair numbers. There are still private shops, home repair, a those that pushed their XHSJSY jeeps off a cliff because they couldn't stand the noise while driving!

This was the case with Autism. Scientist (who look purely at numbers) could not figure out why there was an increase in cases. Environmental? social? What? The answer was simple: Doctors with newer and better diagnosis techniques, were diagnosing more cases. The numbers hadn't changed, they just recognized the symptoms more often.

In fact PART SALES may be a more accurate representation of failures, because generally speaking parts are not preemptively replaced. Certainly not internal engine parts. The loins share would certainly fall into the damaged category. Further, part sales would cover private shops and home mechanics.

I know my post is long and boring, I'm a bit of a scientist myself. I believe this poll is mostly anecdotal, but that is no reason to dismiss these failures (or the poll).

Let me put it in perspective, how many SPONTANEOUSLY dropped valves do you hear about in other vehicles that:

a) have no major internal modifications i.e. oversized cam, non factory pistons etc.
b) have no major external modification i.e roots/centrifugal supercharger, turbo charger
c) that were being driven under normal conditions i.e. no racing, towing, extreme conditions

Is this a problem on other vehicles? Personally I would not know these days, but I have torn down a chevy small block that you could slip a feeler gauge past the compression rings that had original heads that never dropped a valve.

Just sayin.... Where there is smoke there is usually fire....

It is likely a combination of reasons that contribute to this failure, temperature, and lubrication have been mentioned, and, possibly that is what this thread has evolved into: A determination of causes that lead to dropped valves in 4.7L engines.
Jimmy2Ton is offline  
post #130 of 132 Old 01-30-2020, 08:02 AM
mojo509
Registered User
2004 WJ 
 
Join Date: Jan 2018
Posts: 13
Well said Jimmy2Ton. I found this thread to be insightful and informative, and entertaining if nothing else.

Put it in the field, it will yield.
Eventually.
mojo509 is offline  
post #131 of 132 Old 02-13-2020, 11:00 PM
runningonempty
Registered User
2004 WJ 
 
Join Date: Aug 2013
Location: Scotts Bluff
Posts: 91
I'm looking at a dandy 2002 Jeep Grand Cherokee Limited. I don't know after reading this thread if I should take the chance on the 4.7. My 4.0 still doesn't burn oil after 265k. Solid as a rock. Love that engine. Maybe I should put the money in a turbo charger or something like that instead of going to the 4.7 for more power.
runningonempty is offline  
post #132 of 132 Old Today, 10:21 AM
jserna
Registered User
1987 YJ Wrangler 
 
Join Date: Jun 2012
Location: Albuquerque
Posts: 1,192
My 04 Overland had it in #2 as well. Reman engine is going in now. We might fire it up tonight for the first time.
jserna is online now  
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











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