This is actually the design of most intake valves on the market.
The part of the stem that moves through the guide is highly polished and smooth. The part that is in the intake path is rough and sometimes even a smaller diameter.

I do agree that EGR may be a factor.
I also think that the rear most cylinders run hotter, causing some sort of warping/distortion of the head.

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U.S. Army Retired

Did you do anything to verify the matching weight of the piston (look at the stamps)?

-I also haven't had any problems with the ARP torque specs that Geordi advises, although I have stepped these engines up to the 2 hole gasket, as VM Specialist in the UK said it works well, but I have been having every head milled smooth to spec. I've heard of hard starting with going bigger on gasket, but I don't buy it, as my last one starts better than even, despite going with a thicker gasket. I even measured that engine with the dial indicator, and it should have had a no-hole, but the factory put in a one-hole, strange...

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05 CRD: H.D.S2 stat,WW Ironrock trilink&LCA's, OX rear,ARB front, 4.10's, ARB bumper, Suncoast,OME 3.5, JBA UCA,rock rails, Moabs&265/75 Duratracs, GDE tunes ,FFD fan,ARP's, 2 micron fuel, new valves,sasquatch battery tray & grid heater, tensioner relocated
Mech fan, VH & AC delete

I am sorry you are going through this but I admire your persistence, expertise, and adventure. I also enjoy following your progress and findings. I have done all the regular things myself (TB, ARP, WP, GPs, Weeks, etc) so am familiar with the beast. It is the darn challenge that sucks us into this crazy contraption.

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2005 CRD Limited
SEGR
WEEKS Kit (removed EGR, FCV),
Gen 2 Fuel Head
GDE Eco Tune
ARP studs
Etechno (7v) Glow Plugs
F37
Kap 193 thermostat
Carter Lift Pump (Modified wiring harness)
Fumoto (CRD-108)
Bypass oil filter (2 micron)
Samco
Provent
Sears P-1 Battery
Secondary 2 micron fuel filter

That is a very interesting theory, I see a couple problems though.

Everyone is supposed to be running ultra-low sulphur diesel now, and that has a maximum of 15ppm where older low sulphur was around 1500ppm. Quite a difference. There shouldn't be enough left in the fuel to cause the problems you are suspecting.

The other problem I see is that I know of at least 3 other CRDs in the Savannah area besides my own, and none of them dropped valves. It is an unusual and thankfully rare failure mode. I hope that you are able to determine something conclusive but I don't know what we would be able to do with the information.

Nick - Interesting results about the gaskets. Any theories about the compression ratio and any possible changing with a larger gasket?

_________________
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 225 CRDs currently driving with my valves, timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

thank you Denis for your info , dropping valve issue is scary because we spend so much on these jeeps already . thats why i question on this because it wasnt timing issue . well may be VM must have a bad bach of valves or manufacturing problem back then and they didn't expect that egr will corrode them so bad that they just fail. anyway i hope you did run hone brush through cylinder liner to ged new piston rings seated properly . good luck hope she will run good soon

Well, I was worried about poor starting, but I was more worried about valve contact, so I went with the two-hole. GMCTD didn't seem to think that it would make any noticeable difference, and neither does VM Specialist, and apparently the factory didn't care either So, I'm just following greater minds, or greater experience. I am going to continue to measure the protrusion though, as I really wonder if mine was a fluke, or if the assemblers thought it was BS, and just threw in whatever, hmm, or maybe it was just laziness.

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05 CRD: H.D.S2 stat,WW Ironrock trilink&LCA's, OX rear,ARB front, 4.10's, ARB bumper, Suncoast,OME 3.5, JBA UCA,rock rails, Moabs&265/75 Duratracs, GDE tunes ,FFD fan,ARP's, 2 micron fuel, new valves,sasquatch battery tray & grid heater, tensioner relocated
Mech fan, VH & AC delete

Intake valves should never break unless they are subjected to some other influence as they are cooled by the incoming dense fuel/air mixture entering the cylinders. Exhaust valves/stems on the other hand run extremely hot as they are subjected to the very hot gases leaving the cylinder after combustion which causes them to become very brittle. In my many years of mechanical experience, I have only seen exhaust valves break off due to valve stem embrittlement...
Why an intake valve would suddenly break off without coming in contact with a piston really baffles me....
Is there other forces at work here we have just not figured out???????

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Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
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

I admit i did noy check the weight of the piston compared to the old one. I only got 1 used one so it was going in one way or the other. It certainly has to be closer in weight and better in strength than the alternative of grinding down the rough spots on the damaged / old one.

The original liner was in really great shape. Cant believe how clear and pronounced the original cross hatching was. I reused the original rings so they so already be seates back in famiar territory

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Thinking about your reassembling... does the gasket sit around or over the lip of the cylinder liner? I haven't done one in a while so I really can't remember, but I'd be curious if the thicker gasket could / would allow the liner to shift upwards b/c the head wasn't touching / compressing against it, OR as an alternative, if the gasket sits on the liner, if having that contact with a thicker gasket instead allows a tighter seal / compression which would actually make the compression ratio BETTER because the leaves are being squeezed more effectively?

We are only talking about a difference between the no-hole and the two-hole of 20 hundredths IIRC... Not exactly a huge difference overall, and then we are squashing it with ARP studs.

_________________
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 225 CRDs currently driving with my valves, timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

The gasket does not fit over the lip of the liner.
Which makes me think that the lip of the liner should press against the head. But I'm not sure.

_________________
U.S. Army Retired

I call BS on this. When I figure out how to place photos and post links...will hook you all up. Was reading that Mountainman purchased a head gasket from the UK. You can purchase the gasket for $65 + freight depending on exchange rate. A two hole to replace a single. The ARP studs provide more "crush" do the the excessive torque increase. Also... received a fuel rail from Poland with the sensors last month with freight for less than you can purchase both sensors in the states. The gasket sets around the liner...so is a standard crush scenero.



Why worry...these are mass produced engines. Each part is not weighed and the engine balanced on assembly. All the internal components have a tolerance they must meet...or the process does not go forward. My concern would be getting the rings to seat. Past experience has shown that depending on the out of roundness of the cylinder and the taper, may be a chore. I had a Nissan with .002 total run out on one occasion and smoked so bad people thought the building was on fire. We disassembled the engine, got ride of one of the two chrome compression rings and replaced with a cast...not as bad but ugly. So...got with a fellow in New Zealand, purchased two sets of .060 over pistons, ring set and had air freighted to me. Cost was less than three fourths the cost of one set of pistons without the rings. Had them bored...no smoke...runs great. Actually had one balanced and have a turbo on it. Is an LD28 if interested.

Moral of the story...hope it works...however...be repaired of it does not.



Correct...the low sulfur is for emissions. The sulfur was used for lubricity. Lubricity is now taken care of by BIO, fuel conditioner, and 2 stroke oil.

Flash already answered your first question. But, the liner is usually pressed a ways into the head (hundredths or thousandths I'm sure), so the extra compression on the gasket is an excellent thought! hmm, that is as long as the liner being pressed into the head isn't also an important part of the seal/fire ring. I've seen a couple where the liner didn't leave an impression in the head, so I doubt that the liner is supposed to work as a seal. Now that you've pointed it out, I really like the thought of extra compression on the fire-ring of the gasket (the only part that's supposed to contain combustion), so I am feeling more confident about using the 2 holes. They are the only size that VM Specialist sells. I'm guessing it has something to do with successful repairs in the EU where most of these engines are.
Thanks Geordi for pointing this out

Edit: I see, you were saying it would compress it more if the gasket was inbetween the liner and head, which it's not. But, it seems that since the liner is getting pressed into the head, that a thicker gasket would still be getting crushed more, since there wouldn't be as much liner to head contact/resistance. You still got me thinking about this though...

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05 CRD: H.D.S2 stat,WW Ironrock trilink&LCA's, OX rear,ARB front, 4.10's, ARB bumper, Suncoast,OME 3.5, JBA UCA,rock rails, Moabs&265/75 Duratracs, GDE tunes ,FFD fan,ARP's, 2 micron fuel, new valves,sasquatch battery tray & grid heater, tensioner relocated
Mech fan, VH & AC delete

To post pictures.
First you must post the pictures on a site thats viewable to the public. PhotoBucket is a popular site.
Once your image is posted, right click on it and select -copy image url.
When creating your post here, click the Img button, and paste the img url
[img]in--between--these--two--thingys[/img]

Posting links is the same way.
Right click on the url and select -copy.
Then click the URL button and paste the url
[url]in between these two thingys[/url]

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U.S. Army Retired

Thank you flash.

Lots of interesting info, thanks guys. I will have to see if I can get ahold of IDParts first thing this AM before they ship out my box of parts. I ordered a 1hole (matched factory) and will try to get that switched to a 2hole.

I see mention of a preferred ARP torque sequence and ultimate torque spec. What is it?

I was told that one of the stamps on the piston is the weight, so it might be interesting to note your replacement one vs the originals. Probably within spec.

Just follow the factory sequence. I go with about 4 rounds of torquing until I get to the 120/130 that Geordi mentioned. I think the factory procedure calls for 3 rounds, but I split it up for a slower ramp up in torque, as I'm not in a hurry, and want to keep uneven pressure to a minimum. I would definitely advise fully assembling the beast, except for the fuel rail (firewall clearance issues), as getting the rocker cover on is seamless on the stand, but REALLY sucks under the hood... Lifting the head on under the hood is a good way to seriously injure your back also.

_________________
05 CRD: H.D.S2 stat,WW Ironrock trilink&LCA's, OX rear,ARB front, 4.10's, ARB bumper, Suncoast,OME 3.5, JBA UCA,rock rails, Moabs&265/75 Duratracs, GDE tunes ,FFD fan,ARP's, 2 micron fuel, new valves,sasquatch battery tray & grid heater, tensioner relocated
Mech fan, VH & AC delete

The $100 used head showed up today. Overall looks good for 180k miles. There is some excess wear on the #2 exhaust valve. Looks like whoever pulled the head didnt know the idler pulleys are left hand thread. They snapped the bolts off. Luckily theres enough sticking out that i should be able to take the remains out.

Dropping it off at the machine shop in the morning for testing and rebuild.



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well this is what I'm going to say , i wouldnt rush with this type of overhaul i say for my self, in this case i wouldnt reuse old piston rings and also used cylinder head needs to go to machine shop for inspection , again I'm not a fan of speed when comes to this type of work . but its ok its just a piece of iron so it can be repaired agin , good luck.

The head is going to the machine shop. I think i posted that. And with an original/used piston reusing the rings was the only option. You cannot get original rings (thicker top ring) new any more. You must purchase a new piston and ring set together. I had to draw the line somewhere on money being spent on this thing. Plus the old/original rings were fine. There was no reason to toss them out. The same rings are riding in the same cylinder liner as they have been for the last 128k miles. Only the piston is different

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good , no problem i see your point i know its getting too expensive , thats ok its going to run again