It is currently Sun Oct 02, 2022 3:16 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 195 posts ]  Go to page Previous  1 ... 6, 7, 8, 9, 10

Have you had a valve failure? Please fill out the form below (hit quote on post 2) if you have!
Yes 19%  19%  [ 18 ]
No 28%  28%  [ 26 ]
Not Yet (But I'm worried) 32%  32%  [ 30 ]
Not Yet (Not worried) 20%  20%  [ 19 ]
Total votes : 93
Author Message
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Mon Oct 07, 2019 11:49 am 
Offline
LOST Newbie

Joined: Mon Feb 05, 2007 12:37 am
Posts: 89
CRD Year: 2006
Mileage at failure: no failures so far with 200k miles
Mileage with functional EGR: was disconnected in 2007 so, maybe 15k-20k with functioning egr?
Method of EGR delete (elbow, GDE, SEGR, died and you didn't fix): unplugged the MAF sensor and have been staring at a check engine light ever since
Most common driving (city/highway/mountains/etc): mix of everything including lots of towing
Do you have an Exhaust Temp gauge: no

_________________
Jeep on!
--Pete

1 Diesel Liberty and 2 and a half Comanches


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Mon Nov 16, 2020 5:11 pm 
Offline
LOST Junkie

Joined: Sat Oct 01, 2016 8:24 pm
Posts: 652
CRD Year: 2005
Mileage at failure: not failed @ 180k
Mileage with functional EGR: 180k
Most common driving (city/highway/mountains/etc): highway
Do you have an Exhaust Temp gauge: nope

Only reason I am posting this is to note that when I tore the head down the machine shop found most of the intake valve guides were out of spec, resulting in wobbly valves. The engine was out to repair a leak, not for any other failure.... I decided to take the head off 'cause what better time than when it's already on a stand. The truck had zero issues aside from the leak.


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Sun Nov 29, 2020 10:21 am 
Offline
LOST Newbie

Joined: Mon Jun 11, 2018 7:38 am
Posts: 52
WWDiesel wrote:
dkenny wrote:
any thought that this might be caused by the ULSD fuel we have to use the US..
does any one run biodiesel or 2cycle oil for lubrication?
I add 2 cycle oil to my truck, but not the jeep..maybe I should?
-dkenny

I add 2 cycle oil to both my Dodge Cummins and my Jeep CRD! :idea: I started adding 2 cycle oil to the Dodge many years ago back in the late 90s when a mechanic friend that drag races diesel trucks advised me that it was very good for the injection pump since the sorry low sulfur diesel fuel we now have at the fueling stations is the only thing that lubricates the pump and injectors... He stated the low sulfur fuel was not good for diesel engines!!! I used 2 cycle oil in the fuel on the Jeep from day one of ownership when I purchased it used!

In a gallon jug, I simply mix 3 qt.s of non-synthetic 2 cycle oil with 1 qt. of Power Service Diesel Kleen Fuel Additive and pour back into qt. jugs for future use. I add 1 qt. to the jeep CRD at fill up and 2 qt.s to the Dodge at fill up since it has a much bigger tank... This has worked very well for my diesels... :D


And it hasn't gummed up your CAT? Two strokes were banned for a reason...The unburnt oil suspended in their exhaust gases can condense into the lungs of any humans and animals that breath it, causing severe lung damage and lead to lung cancer...Diesel gets bad press as it is, with the cancer causing particulates they expel from their exhausts, so adding unburnt oil into the mix isn't going to help matters. Have you checked to see if it creates higher emissions than stock Diesel? In the UK we have to pass an exhaust emission test every year, as part of our compulsory MOT test, but adding 2 stroke oil may cause it to fail the test. Which would be extremely inconvenient if it did and you had a tank full of the stuff to get rid of before you could book a retest!


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Sun Nov 29, 2020 11:05 am 
Offline
LOST Newbie

Joined: Mon Jun 11, 2018 7:38 am
Posts: 52
Surely the average RPM used must have a bearing on valve failure?
For example, I have the NSG370 6 speed manual box in my 2.8 CRD and I rarely exceed 3000rpm. I often only use 2-3 of the 6 gears because there is so much torque and I cruise around town at 30mph at about 1000rpm in 6th gear all the time, but obviously auto boxes, with less gear ratios and their power hungry torque converter would require the owner to use higher RPM, more of the time, and so that would increase wear and tear on the valves in auto box versions. As such that should have been one of the criteria in geordis original enquiry into this matter.
By the way, did Dent ever get back with the results of his metallurgical analysis of the valves, or it that still ongoing?


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Sun Nov 29, 2020 1:39 pm 
Offline
Moderator
Moderator
User avatar

Joined: Sat Aug 24, 2013 11:36 pm
Posts: 6651
Location: Central GA
As to the Root Cause of exhaust valve failures, which may never be fully ascertained,
The consensus by many on this forum is the exhaust valve failures are caused by overheating of the valve stem in the critical area where the valve head is connected.
Also another big possibility discussed is a poorly manufactured batch of valves as a possible contributing cause since some engines do not seem to experience valve failure issues even above 200k miles. No common denominator to date has been determined, but suspect is that heat is the major factor.

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited :JEEPIN:
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount

98 Dodge Cummins 24 Valve


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Mon Nov 30, 2020 8:57 am 
Offline
LOST Newbie

Joined: Mon Jun 11, 2018 7:38 am
Posts: 52
WWDiesel wrote:
As to the Root Cause of exhaust valve failures, which may never be fully ascertained,
The consensus by many on this forum is the exhaust valve failures are caused by overheating of the valve stem in the critical area where the valve head is connected.
Also another big possibility discussed is a poorly manufactured batch of valves as a possible contributing cause since some engines do not seem to experience valve failure issues even above 200k miles. No common denominator to date has been determined, but suspect is that heat is the major factor.


It certainly underscores the importance of avoiding overheating issues with the VM CRD engines.


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Mon Nov 30, 2020 12:06 pm 
Offline
Moderator
Moderator
User avatar

Joined: Sat Aug 24, 2013 11:36 pm
Posts: 6651
Location: Central GA
jeepsterkj wrote:
It certainly underscores the importance of avoiding overheating issues with the VM CRD engines.

And your statement sir is the very reason why some on this forum are so vehemently opposed to doing anything to the cooling system on this engine that could possibly cause any overheating issues especially in the critical aluminum head area. Their advice and warnings have merit!

:BINGO:

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited :JEEPIN:
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount

98 Dodge Cummins 24 Valve


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Wed Dec 09, 2020 3:28 am 
Offline
LOST Addict
User avatar

Joined: Thu Sep 06, 2007 9:51 pm
Posts: 6291
Location: Somewhere between Heaven and Hell... But it is really hot here on Earth...
Dent's research is available on the forum here, the summary is that the cylinder temperatures over 1200 degrees (or approaching) are the primary factor in causing metallurgical changes of molecule density in the valve stem. Over a period of roughly 300 billion cycles which roughly corresponds with 200k miles, the valve stems reach a fatigue point in conjunction with the molecule density changes that weakened the stems over time - and they just let go without warning. The failure analysis and destructive testing did NOT show a progressive failure over time - when the physical wear limit is reached, poof. It's gone.

Now about cylinder temperatures and engine coolant temperatures - there is NO correlation or causation between the cylinder temperatures and the coolant temps, because in all cases there is a delta of at least 980 degrees (conservatively) between the two temperatures. There will ALWAYS be substantial cooling available to the cylinders, because the coolant is so much colder than the combustion! The valves are NOT affected by the coolant temp in any way, because they are NOT cooled by the coolant, and are experiencing blast-furnace heat directly on them and can ONLY shed that heat through the contact point with the valve seat when the valve is closed.

Do what you like with the cooling system, but a 200 degree cooling system will ALWAYS be a frosty snowball next to a 1200 degree cylinder. The sum total of ways to protect the valve are: Increase boost or reduce fueling, to reduce EGT temps below 1000 degrees. That's it.

_________________
Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 125 CRDs currently driving with my timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.


Top
 Profile  
 
 Post subject: Valve failure research thread - We need your data!
PostPosted: Wed Dec 09, 2020 10:41 am 
Offline
LOST Member

Joined: Thu Jan 10, 2019 10:05 am
Posts: 376
Location: Kennewick, wa
Three words... water methanol injection.... keeps the intake clean too


Sent from my iPad using Tapatalk


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Sun Apr 18, 2021 8:32 pm 
Offline
LOST Newbie

Joined: Sat Feb 20, 2021 9:21 am
Posts: 10
My66dodge wrote:
Three words... water methanol injection.... keeps the intake clean too


Sent from my iPad using Tapatalk

This it may be the solution.
I recently open up my engine as I have a failure I thoth it was the timing belt sliped . I have 5 Exhust roker arms failed as worn out. I checked the valves 4 Exhaust where stiking as stiff not moving. This can be one of the valve cause of failure. The valve stick on the guide and the rocker don`t brake is pushing the valve open that it not return on the seat . Then the piston push it some time perfectly closed some time will bend and distroy the engine. Lucky me in my case my valve where holding compression and no catastrofic damge to the engine. . Complete new head from ID parts are on hold no stock at the moment . I will order coplete valve set repair kit .


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Sun Apr 18, 2021 10:23 pm 
Offline
LOST Newbie

Joined: Sat Feb 20, 2021 9:21 am
Posts: 10
I found this article very interesting
https://www.enginebuildermag.com/1996/0 ... r-options/


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Wed Apr 21, 2021 12:00 am 
Offline
LOST Newbie

Joined: Sat Jun 22, 2019 7:02 pm
Posts: 2
Location: Tampa
CRD Year:2005
Mileage at failure:160k
Mileage with functional EGR:unknown
Method of EGR delete (elbow, GDE, SEGR, died and you didn't fix):elbow
Most common driving (city/highway/mountains/etc):highway75% city25%
Do you have an Exhaust Temp gauge:no
Pre or post turbo:na
If so, most recent average running temp you remember:normal
Any issues with overheating in the recent history before your failure?:no
ARP studs?yes
Replacement rockers?yes
Time / mileage between engine work and valve failure?5k
Which cylinder failed?4
How many valves, and which ones broke?2exh
Did the stem break, and was it where the chrome met the black, in the middle of the black, or at the valve "coin" itself?see pictures
Do you have any pictures, and can you link / post them here please?
Can you also post a picture / report what the cylinder head stamping was?
[imghttps://imageshack.com/i/pn42Wygjj[/img]
[img]https://imageshack.com/i/pm1YCHAWj/img]
[img]https://imageshack.com/i/poKmSErQj/img]

https://imageshack.com/i/pm1YCHAWj
https://imageshack.com/i/poKmSErQj
https://imageshack.com/i/pn42Wygjj

I bought this jeep with a broken timing belt and smashed rockers when my 2006 crd oil sludged and cooked the bearings. My intention was to get the 2005 running and then swap it to the 2006. Well, the 05 parts jeep was running so good after the timing/rockers/arp studs, I keep running it. Then dropped a valve 5000 miles later. I ran it about an hour on the interstate at 80 mph and got off at the exit and stopped at the light. It started rattling upon acceleration then stopped dead and I coasted to a stop. I tried starting but it was locked solid. Hopefully the pictures post so you can see the results of teardown.

I've read this entire post and a common tread I've noted is when the valve failed. One post read almost exactly like mine, but he ran 5hrs on interstate. I was wondering what is happening in this senerio that would lead to a more accurate hopthosis. It seemed ok at 80 mph...what happens when the throttle is closed during interstate exit and the subsequent load of acceleration? Hopefully this leads to an explanation.

_________________
2006 Liberty CRD Limited
163k Miles
EGR Delete
EHM


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Mon Apr 26, 2021 10:50 pm 
Offline
LOST Addict
User avatar

Joined: Thu Sep 06, 2007 9:51 pm
Posts: 6291
Location: Somewhere between Heaven and Hell... But it is really hot here on Earth...
So there isn't a throttle plate on a diesel - and assuming your turbo is operating properly and you are running at normal fuel and boost levels (a leaking injector COULD be a source of issues to hurt the valves) there really isn't any correlation with operating conditions for any length of time to stopping and starting again, and having it fail right then.

I was driving a CRD for hours on the highway and took an exit ramp, and when I started decelerating there was a terrible clanking noise from the transfer case.... And when I stopped, the only gear I had was 4-low. Did the highway trip damage the transfer case? No, that wasn't a contributing factor. There was a failure in the high range output, such that neither high range position worked. The transfer case was munched and when disassembled was massively overheated internally. As it hadn't leaked.... There was just something wrong in it and it failed.

With the valves, the metallurgical testing has been conclusively shown to be caused by high cylinder temperatures over long periods of time. So unless your CRD was programmed with an excessively hot tune / blowing lots of smoke.... Chances are it just reached the fatigue point a little faster than the math said. If there had been lots of city driving or idling in the vehicle's past, it is possible that the number of cycles could have been reached earlier. The best way would be an hour meter, but we don't have that capability either.

I emailed you about a possible engine replacement option, your piston looks like it was cracked off so there is a strong chance that this particular block is done. If it won't rotate now without the head on, that's a bad sign. You'd have to pull it from the body anyway to see if the part of the piston is just jammed in the balance shafts, and then you could possibly put a new piston and sleeve in that slot and it would be serviceable again. These ARE designed to be rebuilt if the block isn't wrecked.

_________________
Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 125 CRDs currently driving with my timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Sat Aug 13, 2022 4:07 pm 
Offline
Moderator
Moderator
User avatar

Joined: Sat Aug 24, 2013 11:36 pm
Posts: 6651
Location: Central GA
Good time to read or reread the Metallurgical Investigation of VM Motori Exhaust Valves if you have not read it before or need to refresh what the study reveals to owner's of the 2.8 VM Motori engine.

One of the items in the study certainly drives home the desire and need for early and total disabling of the soot particulate matter blasting of the exhaust valve stems from the *exhaust soot recirculation system. (*Real name not used)
Excerpt from the study wrote:
A notable decrease in diameter, therefore material loss, in the used specimens is most likely a result of wear. This can occur when combustion products and particulate matter accumulate between the valve and the valve seating and cause abrasion.
The wear rings act as stress concentrators which could also contribute to failure. This is likely because failure was found around the site were the wear rings were located.

Take-a-ways: High exhaust combustion temperatures along with blasting of the exhaust valve stems with soot particulate matter and high cyclic fatigue can all contribute to the to the failure mechanism of the exhaust valves. Removing one or two parts of the equation can certainly help in possibly prolonging the life expectancy of an engine. The sooner you can remove the particulate matter blasting the exhaust valve stems, the better...

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited :JEEPIN:
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount

98 Dodge Cummins 24 Valve


Top
 Profile  
 
 Post subject: Re: Valve failure research thread - We need your data!
PostPosted: Wed Sep 14, 2022 11:19 am 
Offline
LOST Newbie

Joined: Wed Jul 27, 2022 12:06 pm
Posts: 14
Is there any interest in valves that haven't failed? I have 8 exhaust valves from my engine with 114k miles that I removed. I went ahead and replaced them with new OEM valves to be safe while I had the heads off.

_________________
2006 KJ CRD 4x4 Sport
ARP Studs, head gasket, HD water pump, GM 11 blade fan/2786 clutch, HD timing set, new rockers
OME Lift, 235/75/16
In tank lift Pump
Yeti tuned!


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 195 posts ]  Go to page Previous  1 ... 6, 7, 8, 9, 10

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: giacomo.m and 22 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group. Color scheme by ColorizeIt!
Logo by pixeldecals.com