CRD quit, now just cranks but will not fire

Mountainman · **Posted:** Sun Jan 24, 2016 5:22 pm

rankom wrote:

ok guys looking at this broken valve , i say anybody going into rocker job or similar , if head wasn't removed before , just to be safe pull cylinder head anyways is over 100 miles , so that means sending it to machine shop valve removal valve steam seals and valve guide and springs , inspections , i think its beter to do it , or just say drive it and pray , what do you guys opinion on this ????

I think broken valves are rare enough that I would only do the ARP studs unless I have to pull the head. If it's over 200k, it's probably worth pulling it for a valve job though.

rankom · **Posted:** Sun Jan 24, 2016 5:35 pm

thank you Mountainman on your opinion I'm not sure if dropping valve scenario is << rare>> on this engine , but at this point for some people only option is and probably best sending it to scrapyard but for us crd lovers hm we go extra step (rebuild) but that requires lots of loving for jeep logo i yes , give me more excuses please and thanks

dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

Well i am moving forward with pulling the engine. Everything is disconnected except the engine to trans and 2 engine mount bolts. Tomorrow i will take the head to the machine shop to see if its salvageable.

Oh yeah, and flex plate bolts. :oops:

geordi · **Posted:** Mon Jan 25, 2016 1:25 am

Rankom, out of all of the CRDs on this forum or on Facebook, and all the others that we don't know about that were ever sold in North America, I have only ever heard of about six that have dropped a valve. For a vehicle that sold approximately 15,000 to 18,000 in two years, I realize that our experiences here are not conclusive, but even just among this forum, dropped valves are pleasantly rare.

I agree with Nick, I would not suggest pulling the head and wasting the energy unless there is a really good reason. While doing a rocker job, you can just lay a straight-edge across the valve tips and see whether or not there's any kind of problem. If they are all at the same height, chances are better than average that there is not a problem to be found. However, failures due to broken glow plug tips or excessive EGR soot or poor maintenance on oil changes, that can certainly make a big difference.

Edit - fixed a VERY confusing voice-to-text mistranslation.

dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

More thoughts...

I cleaned & inspected the rockers. Amazing good shape. No unusual wear patterns. Rollers have minimal wear including bearing. They all rotate smoothly with virtually no axial or radial free play that would indicate wear necessary to replace them. I expect this might be a bit controversial, but I am not planning to replace them and save $370.

This engine has 128k on the odo. We are only the 3rd owners. First owner had the majority of its life (down in GA - rust free

), the second owner put less than 30k miles on it if I recall the carfax records correctly. The second owner had disabled the EGR by unplugging the sensor. We discussed this when we bought it because I remember it being a bit of a gamble not knowing if that unplugged sensor was the only code lighting the check engine light. Regardless, he seemed to know why it was important to disable the EGR. I suppose it is possible the vehicle was run that way most of its life - maybe from the 1st owner. But I will say that the internals aren't as caked up with exhaust garbage as some of the photos I've seen. Its not pristine inside, but not horrible either. I think this just brings more proof that if you disable the EGR and keep on track with oil changes, rocker wear and failure is not inevitable.

Which I suppose brings me to the critical question of why did a valve fail? It seems that they are rare, at least by the experience noted here. I have seen records of at least one other on a different forum, but that was due to an overheat condition (or at least that was the reason cited). I somewhat question that reason because the stem was bent on that engine - clearly bent before breaking the end off. Here is the other one I found online:

http://www.ar15.com/forums/t_1_134/1482 ... oject.html

Regardless, for the few that have broken a valve - what's going on? I am fairly certain this case was not an overheating condition. I was at the Jeep (after it died) within 15min and it was not hot/overheated. It was full coolant, no steam or any other signs of overheating. I have looked closely at the block, head and head gasket. No signs of leakage across/from any of the passages. Everything appears to have been sealed as it should be.

So what caused the #3 intake valve to just snap off? I am going to say it wasn't piston contact for 2 reasons. First, the engine was 'in time'. I was able to lock both of the cams & flywheel in the correct 90deg past TDC before disassembly. Second, I understand the rockers are designed to fail before breaking a valve. Clearly that did not happen. So it would seem that something else caused the end of the valve to just snap off.

What makes me concerned now is should I be suspect of the other valves in this head? Clearly that concern is moot if the machine shop tells me the head is scrap (taking it in later this AM). But if it isn't, do I just replace the one valve (or possibly both intake valves on #3 - or all 4 valves on #3)? Or do I take the precaution (and spend the $271) and replace all 16?

WWDiesel · **Posted:** Mon Jan 25, 2016 8:06 am

Does not make sense, if nothing hit the valve or got jammed between valve and seat, why would it all of a sudden just break?
I think the only possibility for a dropped valve like yours or one the very few others we have heard of, especially an intake valve since it runs way cooler than the exhaust valve, would be a bad valve with a defect when it was manufactured and it was just a matter of time as to when it would let go.... :roll:

thoughts....

flash7210 · **Posted:** Mon Jan 25, 2016 8:42 am

Sometimes parts just break for no obvious reason.

But...

I know on old cam-in-block gasoline engines, over revving the engine (valve float) will cause valves to break. But this only occurs at 6000+ rpm where the valves are opening and closing so fast that they never fully close and the lifter is actually bouncing off the cam lobe.
On racing engines, this problem is fixed by using stiffer valve springs and retension springs on the lifters.
This doesnt usually occur on overhead cam engines because there are fewer parts between cam lobe and valve stem.
This doesnt usually occur on diesel engines either because they dont rev high enough.

I dont know the specs for the valve springs on the CRD engine but I dont think they are the problem.
Its possible that a collapsed lash adjuster caused the valve to break but it would have been noisy and you would notice the tips of the rocker and valve stem being mashed from all the hammering.

So, I dont know, parts just break sometimes.
But there is really no reason to rev this engine beyond 3000 rpm.

taroo · **Joined:** Sun Apr 27, 2008 2:14 pm **Posts:** 291

dhenderz wrote:

Trying to decide whether to go forward with the EGR delete of some sort, Weeks kit or other method. I understand this will throw the engine light unless I have the ECM reflashed. If it were my vehicle I would just live with the engine light being on. But this is my daughter's Jeep. I really don't like the idea of the engine light being on - and her not being able to know that something else (serious) might be happening/happened to bring the light on. This is her first car so her experience in knowing whether something is not running right or sounding right is limited.

So bottom line, if I go forward with an EGR delete, I will need to get the ECM reflashed. I know there is a thread on this forum dealing with this topic, but honestly of all the engine work I've ever done, ECM reflashing is a new one. And the thought of spending another $500 to have it done just doesn't sit well considering all the other money I will be pouring into this engine. How difficult/tricky is reflashing the ECM with a 'stock' tune, minus the EGR issue?

or find a Synthetic EGR (SEGR) from someone here. I have had a SEGR installed for years with the EGR at first and then after I removed the EGR/FCV, etc and it works great. The SEGR will trick your ECM into thinking you have a EGR and take the EGR out of the circuit. That said, I highly recommend you get the EGR out of the car. Clean the intake port where it may be gummed up from the EGR soot entering the valve cover also.

dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

Cylinder head is at the shop for pressure testing. Fingers crossed.

Mountainman · **Posted:** Mon Jan 25, 2016 12:47 pm

I would definitely replace all of the valves on that cylinder, and I would have to get an expert machinists opinion (with lots of aluminum diesel experience) that the head is 100% before I reused it, just too much work to even think about doing it again. Nevermind if it holds pressure, I'd be just as worried about a possible crack in the future, because that thing got "stamped" pretty significantly. I'd at least check your local junkyards for a cheap head :2cents:

geordi · **Posted:** Mon Jan 25, 2016 2:49 pm

What Nick just said, times 10. I would take the gamble on polishing the piston with a burr and some dremel work... But I'd take an unknown head from a boneyard every day over trying that punched head ever again. That is scrap aluminum, no matter what. WAY WAY too risky.

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dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

I am still waiting on the call from the machine shop. They were pretty busy, might be a few days before I hear about the condition of the current head. But in the meantime, after a little poking around on the net, I scored a grade A used head for $100. :BANANA:

Should be here by Fri.

Snapped it up before someone else does. Figured worst comes to worst I will have 2 good heads and will sell one of them and help offset some of this repair bill. :BINGO:

geordi · **Posted:** Mon Jan 25, 2016 3:38 pm

$100??????? Go buy a lotto ticket and keep the good luck burning! Wow, that is a stunning deal.

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dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

Thinking about a refresh on the head that I purchased. The engine had 180k miles on it (car totaled in a wreck). Probably makes sense to change the valve seals. They're not much money and probably need to be changed. Wondering about the valve guides though. I see they are available via Mopar parts, but they are like $45 each. Say what?? And I don't see them available on ID Parts. Thoughts?

flash7210 · **Posted:** Mon Jan 25, 2016 8:43 pm

A head with that many miles should be checked for cracks.
A good machine shop will disassemble the head, lap the valves, and install new valve guide seals. They should also advise you if new guides are needed.
Be sure to emphasize the need to have the head checked for cracks and pressure tested.

rankom · **Posted:** Mon Jan 25, 2016 9:02 pm

like Geordi says, you may be wasting energy testing cylinder head because they are rarely dropping valves so is it worth risking it ? ask yourself

Mountainman · **Posted:** Mon Jan 25, 2016 9:10 pm

I see Flash already answered, but here's my ramblings, but like he said...

That's one part I haven't bothered with, and my machinist has noted no significant wear on them, but I don't know that I had any over 110k miles. Sadly, most of the higher mileage engines I've wound up with had replaced heads already.

But, if the wear on the cylinder walls is minimal like it should be with 180k, then I would assume the guides are fine also, but I imagine they could be measured?

A little reading about TDI's confirms my assumptions that they are 400k + sort of items, at least that's what others seem to think. I wouldn't pass up the chance for the machinist to inspect them though.

dhenderz · **Joined:** Fri Dec 11, 2015 9:26 am **Posts:** 164

OK, at the risk of starting a raucous debate, I am going to ask a question about the value of ARP studs. Here goes...

I am debating whether the investment in ARP studs is worth it. That is - is there value in the incremental spend. Now before all of you guys start screaming at your screens, let me make sure I lay out the question precisely so we are debating the right thing.

First, I am not questioning the capability of ARP studs nor their superiority in clamping force, uniformity of clamping load or even longevity in maintaining consistent clamp load. To me that isn't a debate because the facts are clear. They are superior in all of those measures (and probably more measures) vs. the factory TTY bolts. But that really isn't the question. The question is value – in this case on an engine that already has 128k miles on the clock. To further lay out the value question I need to take a slight tangent and discuss replacement of the head gasket…

I am about 99% certain that I am going to replace the head gasket. Here's why. You guys know the construction of the gasket. Frankly nothing really special, just 3 layers of steel. The problem is that they are riveted/bonded together such that it is nearly impossible to clean thoroughly between the layers, especially as you get close to the areas where they are bonded. And you guys that have pulled heads, especially with the engine sitting in the Jeep know that it is a wrestling match. There is probably zero chance that small chucks of debris, random crap, etc hasn't found its way between the layers. As you are wrestling the head off/out the head gasket is half stuck to the block and half stuck to the head. The whole thing is springing/stretching apart like a huge slinky. If even a couple of tiny pieces of debris (maybe even 1) gets left between the layers, you have a leak. That's a guarantee no matter what head studs/bolts you use. I know I probably just started a debate/discussion within another debate/discussion – but I am 99% confident I will be buying a new head gasket to insure it is 100% clean/debris free.

So if I am buying a new head gasket, then regardless of which set you purchase (from IDParts), just the head gasket or the full head replacement kits, you get a new set of factory head bolts. As a side note, I did the math on adding up the cost of the individual gaskets vs the cost of the full head replacement set and it is more cost effective to buy the set – again assuming you are planning to purchase a head gasket. Regardless, either path puts you in possession of a new set of factory bolts. You can’t avoid it. You’re getting them. Its like Christmas all over again!

So that makes the purchase of the ARP studs a 100% outlay (premium) because there is no offset and you are tossing the new factory bolts into the trash. The cheapest I’ve found ARP studs is $310 (from Lighting Motorsports). So back to the original question – is $310 worth it? That amount of money pays for the Weeks stage 1 & 2 kits with $20 left over.

Again, I fully agree the ARP studs are superior to factory bolts. But factory bolts aren’t completely ineffective/defective. They do work/last for some reasonable period of time. In my case the engine ran for 128k miles. And I would argue that it wasn’t a head bolt issue that caused my failure. If the valve had not failed, the factory bolts would still be in place and no consideration of replacing them.

Another thing to consider. If this were a low(er) mile vehicle I think the decision would be easier. But it is already sitting at 128k miles. And let’s be candid, what is the vehicle worth (in terms of resale) at this point? Maybe somewhere between $6-7k depending on who’s buying and how they value the CRD ‘premium’. At this point if my daughter gets a couple years of use out of this Jeep, we will probably consider it ‘good’ in terms of cost, depreciation and utility/use.

Again, I know this will be a controversial topic with lots of emotion. But what do you guys think? All things considered, would you invest an extra $310 for ARP studs or save/redirect the cash and roll with the ‘free’ factory bolts?

flash7210 · **Posted:** Tue Jan 26, 2016 9:48 am

It all depends on how long you want to keep the vehicle after its repaired.
At this point you will never see a return in your investment in repairs should you decide to sell it. If you plan to keep it for another 130k miles then I think ARP studs are worth it.
You could completely skip the EGR delete parts too. There are other ways to block or disable the EGR. Just be sure that you don't reconnect the coolant lines to the EGR cooler should it ever start to leak.

Mountainman · **Posted:** Tue Jan 26, 2016 12:32 pm

I you're only going to keep the thing for a couple of years, then it will be worth it for the next owner. But, I just redid one the other day that never sealed with a new head gasket, AND the copper spray stuff. It leaked bad, and it was also a new factory head, so it should have been very flat...
I also have an engine that a dealership failed 3X on with new heads, gasket and factory bolts. Granted they had slightly damaged the top of a sleeve, but ARP's might have held it together, as they had only sanded .030 evenly off an area of the sleeve. Since I'm selling it, I didn't want to chance selling someone crap, so I pulled the engine for a new sleeve :banghead:

and that jeep got my spare engine.

As for the mileage on your engine, it should be almost like new with less than 150k on the clock, unless they didn't change the oil. Since you reported excellent condition rockers (which is rare), I would guess they changed the oil early.
Actually, at that mileage I wouldn't be surprised if you are looking at replacement rockers. Might have been something the PO didn't want to mention, for fear of blowing the sale...

I vote you build it right with ARP's and drive it for 15 years. :JEEPIN:

CRD quit, now just cranks but will not fire

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