Dropping valves/prevention

Mountainman · **Posted:** Thu Mar 20, 2014 1:05 pm

So, I've now read of two instances where a CRD KJ dropped a valve, one at 166 & the other at 170k miles. My question is, since I'm at 164k, what are the odds of this, and what can I do to make sure this doesn't happen to me?

I've built a couple motors more than a decade ago, and barely recall the little retainers that sit within the spring assembly that keep the valves in place. Is it just a matter of these wearing down, and the valves then being able to slip out, or the piece that these retainers pinch into? I'm thinking of adding this preventative maintenance to the rocker, ARP stud, timing belt job. Especially since my EGR wasn't disabled until 164k!

Thanks for reading, and for any advice :JEEPIN:

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

Most of the dropped valves we have seen are due to a very worn rocker that jams/breaks leading to the valve hitting the piston. Having good rocker arms is most likely the best prevention.

Mountainman · **Posted:** Thu Mar 20, 2014 1:29 pm

ah, ok, that makes sense. Thanks Keith! I have a scantool on order to check my readings for rocker condition. They said it won't ship until the 30th :cry:

tomasnc · **Posted:** Thu Mar 20, 2014 8:47 pm

Will a scan tool show rocker arm failure?

dirtmover · **Posted:** Fri Mar 21, 2014 10:17 am

No, it will only identify reduced air intake. You would need to rule out other possible causes for this before concluding that you might have rocker/lifter wear.

Mountainman · **Posted:** Wed Apr 02, 2014 11:53 am

MAF reading was perfect, right in the 135-140 range! I'm thinking that the EGR doesn't destroy the rockers like so many has thought because this engine has 164k of EGR active. But, the turbo is trashed (1/4 inch play)! Maybe the PO's changed the oil often, and that's the real way to take care of the rockers? I'd like to hear GDE's opinion :JEEPIN:

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

The rocker arm wear is dependent on several factors. Oil type, change interval, altitude, driving habits and average speed. The rocker arm life seems to be highly variable with some engines failing by 80k and others lasting 160k with no issues.

Fairly sure Jeep won't be doing a root cause analysis on this one.

Mountainman · **Posted:** Wed Apr 02, 2014 12:43 pm

right on, I guess I got super lucky being that there was 3 previous owners.

Thanks!

Billy M · **Posted:** Wed Apr 02, 2014 3:24 pm

I agree about the oil type & change. I bought my CRD from the original owner. They were a former VW TDI owner, so they had experince with diesel maintenance. They replaced the CRD with another VW TDI. It had consistent oil changes with synthetic (w/documentation) in all things oiled. That was a big selling point for me. It did have the turbo replaced at 80K.??? Another good selling point at the time, but I don't know why it was replaced. I saw the paperwork for it after I got it home. I currently have 122K with no play in the turbo.

Billy

Mountainman · **Posted:** Wed Apr 02, 2014 7:57 pm

Sounds like you got a nice one :rockon:

Mine was a total crap shoot with a bad turbo, and several other issues that I'm still working through. Knowing what I know now I would have checked the turbo, and several other things...

well, I'm about to pull the trigger on a new turbo, if anyone can point me to the link that listed all the necessary gromits and seals I'd appreciate it. I've been looking all over :banghead:

papaindigo · **Posted:** Thu Apr 03, 2014 9:18 am

IDparts has what you need at http://idparts.com/catalog/index.php?cP ... 0f8d62f048

You need:
1. the squarish metal turbocharger gasket - $21.20
2. 2 copper crush washers for the oil feed line banjo fitting - can be found at any decent auto parts store or $5.40 IDParts
3. oil return line upper gasket - the oval one in the return line picture that I think they list separately for $1.99
4. oil return line grommet $7.99 may or may not be ok to reuse.
5. as long as they are solid you can reuse the oil feed and return lines but it would be a good idea to flush them well with solvent to remove any interior crud before reuse.

I personally would not use "pinch" nuts on the turbo to manifold studs. When geordi and I did my Stage II turbo install we discovered, you can imagine how, that those studs are relatively weak and don't react well to removal of "pinch" nuts absent at least 1 day or more of soaking in penetrating lube. Regular nuts and lock washers work just fine.

Mountainman · **Posted:** Thu Apr 03, 2014 10:18 am

Many thanks Pap! I've pretty much had it moth-balled until I get a new turbo in :grim:

Dropping valves/prevention

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