Valve failure research thread - We need your data!

minnisp · **Posted:** Thu Aug 10, 2017 11:44 pm

i have the old valves but he cleaned them up. He said he didn't see anything obvious wrong with them. I'll see if there's anything about them that could be of interest. i'll post some pics

Congrats to the members who started these threads about valves and bolts. it really convinced me to go beyond the collapsed rockers and pull the head. glad i did since there probably already was a coolant leak, and it was likely on its way to further warping and valve trouble. it's a little early to celebrate... i still have to get it back together and get 100,000 miles out of it.

flash7210 · **Posted:** Tue Dec 05, 2017 9:33 pm

Another dropped valve.
Captain Dean posted his with pictures over in the 4x4 section.

And another cracked head.
MicroBruin posted about his today too.

If you’ve made it over 200k miles without a broken valve/head you are doing something right.
Whatever that may be.

Mountainman · **Posted:** Tue Dec 05, 2017 9:55 pm

WWDiesel wrote:

minnisp wrote:

anyone can google "valve failure", but this one isn't infested with pop-ups and advertising (and it's free)
https://www.rroij.com/open-access/failu ... ?aid=44965

Thank you very much for the link! A very good read that reinforces what some on LOST have been saying all along.
It is a shame the picture links on the Web page do not work (404)

I figured out if you click on "View PDF", you can see the pictures in the article and save the article for future reference if you so desire... :wink:

The main takeaway in the article: Fatigue failure is the main cause of valve failure. The fatigue strength is significantly decreased with increase of temperature.
The article does a good job of explaining how high temperatures over time can cause fatigue, stress cracking, and eventual failure!
I am of the opinion that temperature plays a huge roll in the valve failures and / or head cracking that some have unfortunately had happened to them... :roll:

I think the egr soot that collects around the valves makes them hotter (dissipate less heat) and/or causing them to stick, and that this is why egr infested Jeeps drop valves. Although at least half of the ones I get in to have dropped a valve because the rocker collapsed, then came apart, and managed to bind the spring into letting the keepers free. My machinist said the VW's are hard on the guides, I'll have to ask him if he's referring to egr soot laden ones

JeepCRD4Me · **Posted:** Wed Dec 06, 2017 12:13 pm

CRD Year:2006
[/color]Mileage at failure:80,000
Mileage with functional EGR:80,000
Method of EGR delete (elbow, GDE, SEGR, died and you didn't fix):
Most common driving (city/highway/mountains/etc):80/20 city/hw
Do you have an Exhaust Temp gauge:no
Pre or post turbo: ?
If so, most recent average running temp you remember:
Any issues with overheating in the recent history before your failure?:none
ARP studs?no
Replacement rockers?no
Time / mileage between engine work and valve failure? opening motor today
Which cylinder failed? will see
How many valves, and which ones broke? will see
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? ?
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? ?

So ever since my last oil change I have had increased smoke and then TIC TIC TIC. I shut it down and got AAA'ed back to the house. My Mechanic brother and law and I are opening her up to see what it looks like. This the first major repair for my CRD other than the fuel head heater, surp belt and lift pump ing-tank. Any and all input is greatly welcomed. We are in uncharted waters. I am willing to take phone calls even. e-mail me at fishinfruition@yahoo.com will talk and take advise we know we need it.

Mountainman · **Posted:** Wed Dec 06, 2017 3:08 pm

JeepCRD4Me wrote:

CRD Year:2006
[/color]Mileage at failure:80,000
Mileage with functional EGR:80,000
Method of EGR delete (elbow, GDE, SEGR, died and you didn't fix):
Most common driving (city/highway/mountains/etc):80/20 city/hw
Do you have an Exhaust Temp gauge:no
Pre or post turbo: ?
If so, most recent average running temp you remember:
Any issues with overheating in the recent history before your failure?:none
ARP studs?no
Replacement rockers?no
Time / mileage between engine work and valve failure? opening motor today
Which cylinder failed? will see
How many valves, and which ones broke? will see
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? ?
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? ?

So ever since my last oil change I have had increased smoke and then TIC TIC TIC. I shut it down and got AAA'ed back to the house. My Mechanic brother and law and I are opening her up to see what it looks like. This the first major repair for my CRD other than the fuel head heater, surp belt and lift pump ing-tank. Any and all input is greatly welcomed. We are in uncharted waters. I am willing to take phone calls even. e-mail me at fishinfruition@yahoo.com will talk and take advise we know we need it.

So it still runs? Don't start it, but if so, a light tic is probably not a dropped valve. Probably collapsed rocker, likely need a cam. Maybe a rod bearing if it's more of a light knock. Main bearing sounds like smacking a big hammer on the side of the block down low...

JeepCRD4Me · **Posted:** Wed Dec 06, 2017 7:21 pm

So it still runs? Don't start it, but if so, a light tic is probably not a dropped valve. Probably collapsed rocker, likely need a cam. Maybe a rod bearing if it's more of a light knock. Main bearing sounds like smacking a big hammer on the side of the block down low...[/quote]

Mountainman
That's kind of encouraging. It did run even after the tow. It sounded like one nut in a tin coffee can. What is with the timing cover holding down the top of engine cover? Do we need to pull the fan clutch and timing cover to get at fasteners in that area?

flash7210 · **Posted:** Wed Dec 06, 2017 8:46 pm

Removing the valve cover requires all the same procedures for replacing the timing belt and water pump.
After that you remove the fuel rail and injectors to unbolt and remove the valve cover.
It also help to disconnect the wiring harness connections on the passenger side so you can move the harness out of the way.

If you haven’t yet replaced your timing belt and water pump, now would be a good time.
It would also be a good time to delete your EGR valve.

Mountainman · **Posted:** Wed Dec 06, 2017 9:20 pm

JeepCRD4Me wrote:

So it still runs? Don't start it, but if so, a light tic is probably not a dropped valve. Probably collapsed rocker, likely need a cam. Maybe a rod bearing if it's more of a light knock. Main bearing sounds like smacking a big hammer on the side of the block down low...

Mountainman
That's kind of encouraging. It did run even after the tow. It sounded like one nut in a tin coffee can. What is with the timing cover holding down the top of engine cover? Do we need to pull the fan clutch and timing cover to get at fasteners in that area?[/quote]

How long did it run for with that sound, and was it a fairly consistent sound? Rod bearing sucks because you still have to pull the engine, but that would give a consistent knock, like clock work idle

JeepCRD4Me · **Posted:** Sat Dec 09, 2017 2:50 pm

So after the big nut in a coffee can sounds came the run time was maybe 15 second. Also is that fan clutch nut a left or right to remove. Its is giving us fits. I am going to move this to a new thread.

valoflyby · **Posted:** Sun Apr 22, 2018 12:43 pm

geordi wrote:

CRD Year:
Mileage at failure: Under 70k
Mileage with functional EGR: Under 10k
Method of EGR delete (elbow, GDE, SEGR, died and you didn't fix):SEGR when it was introduced, GDE later
Most common driving (city/highway/mountains/etc):Combo: 75% City, 22% Highway, 3% Towing
Do you have an Exhaust Temp gauge: No
Pre or post turbo:
If so, most recent average running temp you remember:
Any issues with overheating in the recent history before your failure?:No
ARP studs?No
Replacement rockers? No
Time / mileage between engine work and valve failure?Timing belt was replaced 14 months prior, ~7K miles, HDS thermostat installed 3 months prior, ~2K miles
Which cylinder failed?#3
How many valves, and which ones broke?One, Exhaust
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?Middle of black
Do you have any pictures, and can you link / post them here please? Will attempt to do so
Can you also post a picture / report what the cylinder head stamping was?

Vehicle purchased 2/2005. Used for light towing of motorcycle race trailer, occasionally flat-pulling a Miata. Was on a trip, Jeep had been running for ~5 hours, came off highway, came to stop sign, accelerated away, hit 2nd, rattled like mad, then silent and I was coasting. Attempted restart, rattled then refused to turn over. Coasted. Had vehicle towed. Sat for 6 months before finally getting the time to dig into it. Immediately found #3 injector showing impact damage. Pulling the intake manifold (whatever we call that thing) and saw one raised valve spring.

Valve failure research thread - We need your data!

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