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New project - Found 2 dropped valves.
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=84891		 Page 1 of 2
Author:  geordi [ Fri Jul 01, 2016 3:58 pm ]
Post subject:  New project - Found 2 dropped valves.
So this is another example of what happens when things that shouldn't be in the cylinder manage to get in there.

I don't know if the glow plugs had anything to do with it, but this engine still had the original ceramic plugs. NO GOOD!
Someone was inside this engine at some point in its 200k mile life, as it had the new style lifters but did NOT have studs. That suggests that it was a dealership that did the work and maybe buggered the timing at some point. The engine still rotates smoothly, but with all the chunks out of this piston I think it probably needs to be pulled and a piston / sleeve put in. Then I still need to source a cylinder head for it.

This is the #1 cylinder and both exhaust valves were the ones that broke. Only one rocker was cracked and just barely - one of the two damaged valves.

Ignore how the top of the deck looks - I covered it in packing tape to keep the ports and other cylinders clean while I was cleaning the top of this piston with a brass dremel brush. That is why the deck looks weird.

Anyone got a decent shortblock laying around and / or a decent head? Email me if you do and maybe we can work something out.

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Author:  geordi [ Fri Jul 01, 2016 7:05 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
I disassembled part of the head, and pulled out the offending valve stems. The two intake valves are VERY bent, but came out easily once the clips were removed. That says that all damage was below the guides. Even these two came out easily through the guides.

I do not believe that the valve guides are related to this failure mode, but I need to talk to people smarter than I am about this. To my eye, the stem that broke straight across was the first failure, and the loose cap caused the second valve to bend / shatter, which then started pounding on the two intake valves, but the engine stopped hitting itself before they failed too.

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Author:  rankom [ Fri Jul 01, 2016 7:47 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
GEORDI you know we are in the same boat so were all smart ok well lets see we have CRD jeep LOL anyway , we where looking into this issue many times , we seen bad timing can cause this problem , faulty parts , bad workmanship ,,, an so on , glow plugs etc . i wonder is it possible that something loose into air intercooler floats around or when we remove CAC hoses something goes into intake and jumps valves , or we need to be more careful and clean intake properly so noting can fall inside cylinders ,
Author:  geordi [ Fri Jul 01, 2016 8:23 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
Let me stop you there - If one engine had crap in the cylinders from the intake, I could maybe accept that. Two starts to look like a trend, but with this many that I've heard about or seen in person... My own personal experience of seeing the results in person now numbers about 8 different engines. Several of which that I also worked on, so you know that I wasn't dropping stuff in the cylinders!

I'd like to blame poor maintenance, but even that is starting to be ruled out. I need to talk to some people that know things about this, but we might actually have a class action here. This is starting to really seem like a design flaw. Maybe the springs aren't strong enough, or maybe the lifters are too tall and hold the valve open... If the timing is wrong, then the rockers should suffer. That is the design, and I have seen where that has functioned perfectly.

The only rocker on this engine that was broken was the rear exhaust valve on the #1 cylinder - the stem that is not cleanly broken. Why would a valve separate perfectly flat? That seems like a manufacturing flaw to me, but like I said - I need to research more and talk to people that know these type of things.
Author:  95Z28A4 [ Fri Jul 01, 2016 9:02 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
Geordi,
Last weekend we talked about machining over-the-counter valves to fit the CRD. Enthusiast did this for the 4.0L Jeep engine before larger aftermarket valves were available. Of course research will have to be done to find a suitable sized valve that requires minimal machining. If an aftermarket version of this valve is available in stainless, then the valve manufacturer could be called to confirm compatibility with the CRD.

It seems Manley will custom manufacture valves to size.

http://www.manleyperformance.com/dl/custom_valves.pdf
Author:  jws84_02 [ Fri Jul 01, 2016 9:14 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
95Z28A4 wrote:
Geordi,
Last weekend we talked about machining over-the-counter valves to fit the CRD. Enthusiast did this for the 4.0L Jeep engine before larger aftermarket valves were available. Of course research will have to be done to find a suitable sized valve that requires minimal machining. If an aftermarket version of this valve is available in stainless, then the valve manufacturer could be called to confirm compatibility with the CRD.

It seems Manley will custom manufacture valves to size.

http://www.manleyperformance.com/dl/custom_valves.pdf


I think we are heading down the right path with this comment. I don't have much knowledge on this matter but do think aftermarket valves is part of a solution that is needed
Author:  geordi [ Fri Jul 01, 2016 11:43 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
Mike, I'm right there with you - I think aftermarket will end up being the answer. I hate the fact that it will require full disassembly of each engine to upgrade the valves, but that is less work than pulling the whole thing to replace it when it munches a piston like this. That will *absolutely* push each of those jobs into second day territory, and I don't know if people will really want to have me do it, but if that is the only answer... Est la guerre.

Meanwhile, on the research front... I did some reading online and then went back and pulled a couple more valves out. The exhaust valve that failed actually separated midway between the weld (where the color changes from chrome to black) and the fillet or the tapered portion of the valve itself. What this means is that it broke in a spot that should never be under any stress other than tension or stretching lengthwise along the stem. It shouldn't have broken there.

I'm going to create a new thread shortly, and hopefully anyone that has had valve failures can respond and we can start gathering more information. This is something that definitely rises to the level of a design flaw, and might even be class-action fodder if Chrysler didn't have any part in the selection of the specific valves. VM supplied the engines, were they supplied already built? VM never claimed bankruptcy, and maybe they were sending over shoddy valves!
Author:  95Z28A4 [ Sat Jul 02, 2016 9:06 am ]
Post subject:  Re: New project - Found 2 dropped valves.
Jim,
How close are you to Ft Lauderdale? You may recall that I said that I had Ferrea valves installed in my Z28. Ferrea is loacated in Ft. Lauderdale. Ferrea sells valves for Fiat with triple groove stems. It seems they may have the ability to manufacture valves for the CRD.

http://www.ferrea.com/Fiat-Engine-Valves/p34279

Maybe you could setup an appointment and bring some examples of failed valves to them. If you can bring several broken valves (I would bring the associated keepers and retainers, also), a damaged cylinder head and a damaged piston, it may engage their interest better than just a couple broken valves.

Possibly LOST members who still have broken valves could send them to Geordi to bring to Ferrrea for evaluation? The greater variety of failures seen. the more accurate the analysis.

I hear what you're saying about this being a two day job. I can only speak for myself, but if Ferrea can definitely point to a design defect or manufacturing flaw and manufacture bullet proof replacements, I will go back into the CRD engine, pull the head and replace the valves.

I just had a thought.......This is the first engine that I have heard of the has sacrificial rocker arms. Maybe the hardness of the valves is engineered with the rocker arms to ensure the rockers break before the valves bend. Maybe in some case the valves are a bit too hard and are brittle causing the valves to fail from normal fatigue? I think the new valve design should ignore the part the valves play with the sacrificial rockers. Design the valves for maximum durability. If someone fails to change the timing belt in a timely and the engine is wrecked, then I see that as owner error. It wouldn't be the first time this type of neglect has ruined an engine.
Author:  WWDiesel [ Sat Jul 02, 2016 12:10 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
Just to add a little to the discussion;
geordi and all, the valve on the left in the picture that is broke cleanly is exactly what I used to see in VW air cooled engines that dropped a valve and they were notorious for doing this. The VW air cooled engine ran much hotter than a water cooled engine and temperatures may have contributed to the valve failures. I personally saw hundreds of these failed valves and all broke cleanly just at the start of the taper just as the CRD valve pictured. There was never any class action lawsuits filed that I was aware of. We were always told by the OEM engineers that the reason for the breakage was due to valve stem embrittlement due to the extremely high operating temperatures the exhaust valves were subjected to. :roll:

The solution back then was to install stainless steel Sodium Filled exhaust valves in place of the OEM valves as they just did not break off as did the OEM valves...

If my memory serves me correctly, we ordered the stainless steel Sodium Filled exhaust valves from "Manley Valves".
http://www.manleyperformance.com/
This is the special order spec sheet for ordering custom valves: http://www.manleyperformance.com/dl/custom_valves.pdf

Now if we could get Manley or another vendor to make some of these type of exhaust valves for the CRD it may certainly be worth a head removal / valve job to replace them to prevent a catastrophic failure.... :idea:
Author:  geordi [ Sat Jul 02, 2016 1:17 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
I've been reading about those sodium valves, and they certainly look interesting. I've also been reading up on the signs of valve failure and these (and many others that I have looked at that aren't broken) do not show any evidence of being over-temp. There is no evidence of charring or ash depositing on the valves, no evidence of galling or "adhesive wear" that I can see where the contact points with the guide would have stripped the chrome from lack of lube... It just seems like it snapped with no obvious reason.

I will definitely be bringing the head and valves to Ferrea next week, thanks for the info! Depending on what they say, maybe sodium valves are the answer, but I don't know. I don't really think the heat is an issue. The ONLY heat explanation that makes any sense is if the engine is running too hot of an exhaust temp b/c it is overfueling based on the air charge... Because the EGR is not fully closed and is leaking boost out.

I managed to melt a piston on my VW TDI. The engine was running great, but fuel economy had been dropping slowly. I didn't really notice it b/c I had been towing a cargo trailer though, but I *had* seen excessive smoke and soot on the trailer and back of the car. The boost was higher than expected for reasons I was unclear about... Then eventually I got an oil pressure light b/c the motor had been leaking into that cylinder.

What happened? The chain of events as I understand it: An injector tip had become worn after about 100k miles of operation, and was drooling / overfueling the one cylinder. That causes excessive cylinder temps, but they were masked by either light duty operation or towing (engine cooling hid the damage as it was happening or lowered economy masked by towing). When the cylinder temps got so hot from the excess fuel that the piston crown started to melt around the edges, the oil started to be consumed. This progressed until the oil level became critical while operating at 70mph (towing) and finally I shut it down when the idiot light came on.

On a diesel, when it is working hard and getting hot, you REDUCE FUEL to cool the engine or you risk melting a piston. So increasing the air (or boost) in relation to the fuel will cool the engine. If you are leaking boost, the computer doesn't know this and you are increasing the cylinder temperatures.

I'm not ready to fully blame the EGR (yet again) for this... But why aren't the european 2.5 and 2.8 CRDs having the EXACT SAME failures if this is a design flaw? It would seem that the EGR is the main difference between the two designs.
Author:  WWDiesel [ Sat Jul 02, 2016 3:35 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
All of what you say makes a lot of sense! A slightly leaking EGR valve would cause some low boost and certainly affect the fuel air ratio entering the cylinder and thus affect the EGT exiting the cylinders.

This I know for a fact as I have a EGT gauge (hardwired thermocouple) on my Dodge Cummins and have to back off on the fueling box when the EGT start exceeding 1300 deg.s F as anything at that temp or above can start melting piston tops. I can run over 40 psig boost at full go petal and max fueling on the box...

When I experienced a leaking boost pipe hose connection a few years back before I replaced all of them with the super heavy duty silicone connectors, I was loosing some boost and EGT's were going above the 1300 limit so quickly and much easier than normal and that got me to looking for the boost leak problem!

Well, back to blaming the EGR system and another sound reason to get rid of the stupid thing altogether.... glad mine is gone!!!! :BANANA:
Author:  95Z28A4 [ Sat Jul 02, 2016 4:32 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
WWDiesel wrote:
Well, back to blaming the EGR system and another sound reason to get rid of the stupid thing altogether.... glad mine is gone!!!! :BANANA:


I'm not convinced it is the EGR causing the valve failures.

Jim, if you're planning to start a dropped valve data gathering thread, I suggest you request total mileage and mileage with EGR enabled at the time of the failure.

My wife's CRD has 102k miles and ran for 49k miles with EGR. When Jim pulled the intake manifold / valve cover from the engine this past weekend, the intake manifold was shocking clean. It had a thin film of soot in most areas and in some areas bare aluminum could be seen. My fear may be unfounded, but I am afraid that her CRD may drop a valve at anytime.
Author:  flash7210 [ Sat Jul 02, 2016 6:02 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
I think the problem is related to heat.
Whether it's too high EGT or poor heat transfer through the head, I don't know.

I'm sure sodium filled exhaust would work great.
I doubt that our valves are so special that custom made ones are required. I'm sure Manley or whomever will have something.
Author:  rankom [ Sat Jul 02, 2016 9:46 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
well i had some time today so i stop at my neighbourhood chrysler dealer to see if they had any experience with this ? response was ,last time they work on one of this engines , (head gasket job) customer come back on the hook next day ,valve dropped without warning , so , long block needed to be installed . they couldn't explain any more details and thats it , so i had to leave and laugh like i never heard this before ,,,,
Author:  geordi [ Sun Jul 03, 2016 1:34 am ]
Post subject:  Re: New project - Found 2 dropped valves.
That makes at least 3 that have now dropped valves in rapid succession to having the rockers touched or the head gasket replaced.

This does not make a trend, but it is disturbing. Why would the valves suddenly fall apart if they only have fresh rockers sitting on top of them? There is an assumption that they are being timed correctly, but a dealership would most likely not have installed ARP, so that somewhat rules out compressive strength pulling the head / valves closer to the pistons.

Maybe the lifters are too tall in the new design? But then why wouldn't every CRD have this problem if it is related to timing or physical contact? I'm inclined to still think it is related to heat somewhere along the line.

This also begs the question - has anyone with the GDE hot tune or eco tune suffered a valve drop?
Author:  flash7210 [ Sun Jul 03, 2016 7:59 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
Quote:
This also begs the question - has anyone with the GDE hot tune or eco tune suffered a valve drop?


Naturist had a GDE tune.
I bought his ECU.
Author:  flash7210 [ Sun Jul 03, 2016 8:09 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
Any indication of piston-to-valve contact in the other pistions?
That could be a clue about the possibility of a bothced t-belt job.

Samse101 is in Austria and he had a broken valve.
Dhenderz had a broken valve.
And in my "keeping a cool head" thread, there were two others reporting broken valves.
These were all recent posts from within the last couple months.
There have been others over the years but it difficult to search for them.
Author:  geordi [ Sun Jul 03, 2016 8:41 pm ]
Post subject:  Re: New project - Found 2 dropped valves.
For anyone that can - Please add your information (what you know of it) to the new valve research thread so that it can be collected in one place.

As far as evidence of contact in the other cylinders, the answer is no - at least on this current CRD. This one was Patrick Henry's and I will be adding the information to the survey shortly. I already put in Naturist's info, as I had worked on his so I knew what the particulars were.
Author:  Dgideon [ Mon Jul 04, 2016 9:37 am ]
Post subject:  Re: New project - Found 2 dropped valves.
I've been thinking about the "two (2) dropped exhaust valves" in the same cylinder.

Very likely the engine "dropped" the first exhaust valve into the cylinder and then this first "dropped" valve caused the fracture of the second exhaust valve. In other words, the first "dropped" valve caused the second "dropped" valve.

Good chance of a cracked head plus damage to the piston & cylinder liner and possibly a twisted connecting rod. :(
Author:  WWDiesel [ Mon Jul 04, 2016 10:44 am ]
Post subject:  Re: New project - Found 2 dropped valves.
Dgideon wrote:
I've been thinking about the "two (2) dropped exhaust valves" in the same cylinder.

Very likely the engine "dropped" the first exhaust valve into the cylinder and then this first "dropped" valve caused the fracture of the second exhaust valve. In other words, the first "dropped" valve caused the second "dropped" valve.

Good chance of a cracked head plus damage to the piston & cylinder liner and possibly a twisted connecting rod. :(

I totally agree, that is why one of the valve stems (one on right in picture OP) was not broken off cleanly as the first one but had a ragged broken stem and in a different location almost like it was bent over first before breaking off finely... :roll:
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