CRD rocker arm wear...more info

kjjet · **Posted:** Tue Aug 27, 2013 8:47 am

I believe that the Rockers are lubricated (oiled) by the oil that is pumped to the intake. The oil is provided to the cams and then falls down onto the rockers/ rollers.

So...it can be said that rocker rollers do not get a direct oil pressure lubrication and main & connecting rod bearings do. This is why they wear out first due to soot in the oil.

flash7210 · **Posted:** Tue Aug 27, 2013 8:54 am

You are correct.
Splash lubrication for the rocker arms.

tigafila · **Posted:** Tue Aug 27, 2013 9:08 am

Thank you Flash for making my points.

The pathway for combustion/EGR soot should be down the cylinder walls, by way of blow-by,
into the crankcase oil, then up the all the surfaces requiring lubrication.
(unless there is another pathway I am not aware of)
There is no other pathway, EGR proximity to the rockers has nothing to do with these issues.
I suspect that rod/main bearings may be better suited for handling soot and other contaminants.
The purpose of the babbitt is to imbed the particles that could score the journals, on mine there was nothing imbedded. I think if it was more of a soot problem than an oil quantity/quality problem that there would have been at least a little scuffing or discoloration on the babbitt on my rod or main bearings but there was absolutely none, all of my bearings looked like brand new.
The bearings in the rocker arms may be of poor quality or poorly engineered. Contaminants in
the oil build up on the bearings and the constant friction causes bearing failure.
This may be possible but it doesn't explain why at 100k the only rockers I had to replace were the ones destroyed when it swallowed a valve and also why at 150k I am still running all original rockers except those 4.

Crankshaft bearings are continually fed oil by direct pressure. Oil is continually being pushed through
the bearing surfaces. The only thing that keeps the crankshaft journal from
touching the bearing surface is oil pressure. Agreed

Every rocker arm I have ever seen, whether roller bearing or not, uses splash lubrication.
There is no direct oil pressure on those bearings. Agreed but it doesn't mean they all fail. If it were a soot problem and obviously there is only one path for the soot, down the cylinder walls, I would expect to see more cylinder, ring, and piston wear. I don't see any posts about those issues, and mine were all beautiful.

kjjet · **Posted:** Tue Aug 27, 2013 11:35 am

tigafila

FYI....there have been lots of connecting rod bearing failures in these engines. Its the 2nd thing that fails after the rockers.

Its my belief that the rockers rollers were not designed for a EGR engine here in the US. These same engines are operating in Europe with no issues.

I hope VM designs their new engines with better quality rocker materials that will hold up to US EGR standards. Until i know this for sure, I will not be purchasing a VM engine in anything.

That's my :2cents:

Hexus · **Posted:** Tue Aug 27, 2013 12:02 pm

I'm going to note a few more things, then I'm done talking about this unless asked.

Chrysler calls the FCV valve an EGR as well. Ask a Chrysler tech bout EGR and they'll tell you a VM Diesel has 2 EGR Valves. Even though 1 is an FCV. There are 2 different codes for EGR failure in the FSM, and one is the actual EGR and another is the FCV.

I believe Geordi had 2 Rod Bearing/Rod/Lower end issues exactly like what he's talking about with no real explanation, well maybe a turbo on the 1st one and oil starved IIRC.

I have personally taken apart 4 of these engines on the top end, 3 with broken rockers on the #3 Cylinder including my own with a broken lifter (of all things, shattered) and worn rockers/seized rollers. The other one had some very obvious wear on the Lifters (You can ask TennesseeCRD to attest to this one).

While your engine may not have suffered these issues, and there are some folks who are either "lucky" or possibly didn't get the same "run/batch/group" of rockers/lifters some of the rest of us experienced.

I honestly and sincerely say "good for you" that you haven't had the issues the rest of us have had, but I know what I have witnessed first hand in the ones I have taken apart.

flash7210 · **Posted:** Tue Aug 27, 2013 12:05 pm

Hexus wrote:

While your engine may not have suffered these issues, and there are some folks who are either "lucky" or possibly didn't get the same "run/batch/group" of rockers/lifters some of the rest of us experienced.

I agree with this statement.

papaindigo · **Posted:** Tue Aug 27, 2013 12:27 pm

For what it's worth:
1. Figure 58 of the KJ VM Diesel Engine Repair "classroom" document shows a diagram of the oil flow. As nearly as I can tell the lifters are supplied oil from the left and right upper main oil gallery and the cam bearings directly receive oil under pressure from those galleries. Rockers are not directly provided with oil under pressure.
2. as far as I know both domestic and export KJ CRDs have the EGR valve, not to be confused with the FCV valve, however the operational mechanism and operational programming appears to be different. I suspect the domestic models have much more "active" EGRs, absent a GDE tune, than the export models.

SFHLibertyCRD · **Posted:** Mon Oct 14, 2013 5:37 pm

After I did the following, my MAF idle number now reads 17.5+ (I am about 165 feet above sea level) :BANANA:

, anyone know which of the following might have done the trick? Perhaps my rockers are in decent health after all? Prior to this, I was getting a consistent 16.5 idle MAF. Here is what I did this weekend:
- Replaced my MAP sensor with the cheaper Bosch replacement (old one was a bit gunked, but not too bad, but their were a few broken pieces of plastic on the little cage around the sensor)
- Replaced air filter (old one was stiff, warped, and looked terrible)
- purchased a new top for the air filter box (previous one was kinked at the turbo hose outlet)
- Cleaned my MAF sensor with MAF cleaner

How does ambient air temperature play into these numbers anyway?

It also seems to idle and run more smoothly.

CATCRD · **Posted:** Mon Oct 14, 2013 8:56 pm

SFHLibertyCRD wrote:

After I did the following, my MAF idle number now reads 17.5+ (I am about 165 feet above sea level) :BANANA:

, anyone know which of the following might have done the trick? Perhaps my rockers are in decent health after all? Prior to this, I was getting a consistent 16.5 idle MAF. Here is what I did this weekend:
- Replaced my MAP sensor with the cheaper Bosch replacement (old one was a bit gunked, but not too bad, but their were a few broken pieces of plastic on the little cage around the sensor)
- Replaced air filter (old one was stiff, warped, and looked terrible)
- purchased a new top for the air filter box (previous one was kinked at the turbo hose outlet)
- Cleaned my MAF sensor with MAF cleaner

How does ambient air temperature play into these numbers anyway?

It also seems to idle and run more smoothly.

The middle two had the biggest effect. If unmetered air was getting in the kinked joint that would lower your reading. Ambient temp does have a big effect though.

SFHLibertyCRD · **Posted:** Mon Oct 14, 2013 9:02 pm

CATCRD wrote:

The middle two had the biggest effect. If unmetered air was getting in the kinked joint that would lower your reading. Ambient temp does have a big effect though.

In general, how does ambient temp effect the reading? Colder makes it higher or lower?

CATCRD · **Posted:** Mon Oct 14, 2013 9:24 pm

SFHLibertyCRD wrote:

CATCRD wrote:

The middle two had the biggest effect. If unmetered air was getting in the kinked joint that would lower your reading. Ambient temp does have a big effect though.

In general, how does ambient temp effect the reading? Colder makes it higher or lower?

Colder is higher. Denser air.

SFHLibertyCRD · **Posted:** Tue Oct 15, 2013 12:52 am

CATCRD wrote:

SFHLibertyCRD wrote:

CATCRD wrote:

The middle two had the biggest effect. If unmetered air was getting in the kinked joint that would lower your reading. Ambient temp does have a big effect though.

In general, how does ambient temp effect the reading? Colder makes it higher or lower?

Colder is higher. Denser air.

Interesting. Could it make a difference of one whole g/s though? The temperature was probably 10-20 degrees colder than the last time I checked. I'll have to try again sometime in warmer temperatures and see what kind of variation I get.

dennhop · **Posted:** Fri Apr 25, 2014 7:09 pm

Welp, just did the test, and according to the numbers, my rockers are shot, no ifs ands or buts about it. Bad thing is I have to continue to drive it, until I can get the truck running again...FML. Unless someone sees something I didn't, here's my numbers and results...

760 RPM
MAF - fluctuated up and down, a few points at a time between 14.6 and 15.6 g/s. I ran the numbers both an average between the two, at 15.1 g/s and at 15.6 g/s.
Coolant temp was 185 degrees
IAT read 127.4 degrees
Outside temp was 66 degrees,
and 715 ft above sea level, here in Indy.
My first calculation, using 15.1 g/s put me at 596.
second, running 15.6 g/s, put me at 615.

Mountainman · **Posted:** Sat Apr 26, 2014 12:35 pm

Might your intake be partially choked off from gunk, or fcv valve, air filter, or some other obstruction or leak that the MAF in the air box isn't seeing? I'd pull the CAC hose off the intake and go at it with a spoon, and solve any air leaks, and run a new air filter. Is your airbox to turbo hose sucking air at the turbo like they all tend to do after a few years (it tears right at the hose clamp)?

Mountainman · **Posted:** Sat Apr 26, 2014 2:47 pm

Well, I hadn't stumbled accross this post until yesterday :banghead:

There is an incredible amount of info on this site!
But, I've mentioned it elsewhere, my engine sure points towards EGR/soot not being all that destructive (maybe). I have good MAF readings, and this beast had stock EGR action until I got it at 164k. I'm going to eventually pull the intake to clean it well, and do a check of the rockers, maybe even ARPs while I'm in there.
The power is excellent, although it does sound like it has a miss at idle, not super smooth idle (maybe it has a wasted rocker?).

My only other thought on this thread that might really mess up what we think the rocker wear is, and that's the fact that a previous owner (there were 2 or 3) could have put a new head on this prior to me getting it. Maybe it had HG issues like so many have, or a top end explosion, and the stealer replaced head, rockers or who knows. Any head serial numbers that are corelated to the VIN? Chrysler claims there are almost no repairs in their system...

Thanks for reading and for the Awesome thread :rockon:

Smacker · **Posted:** Sat Apr 26, 2014 3:23 pm

You could check the date code that is stamped on the head between #1 and #2 glow plug. my Original Head was a 2005 and a Refurbed one I got had a 2007 date stamped in it.

Mountainman · **Posted:** Sat Apr 26, 2014 3:33 pm

right on, thanks Smacker!

geordi · **Posted:** Sat Apr 26, 2014 3:42 pm

dennhop wrote:

Welp, just did the test, and according to the numbers, my rockers are shot, no ifs ands or buts about it. Bad thing is I have to continue to drive it, until I can get the truck running again...FML. Unless someone sees something I didn't, here's my numbers and results...

760 RPM
MAF - fluctuated up and down, a few points at a time between 14.6 and 15.6 g/s. I ran the numbers both an average between the two, at 15.1 g/s and at 15.6 g/s.
Coolant temp was 185 degrees
IAT read 127.4 degrees
Outside temp was 66 degrees,
and 715 ft above sea level, here in Indy.
My first calculation, using 15.1 g/s put me at 596.
second, running 15.6 g/s, put me at 615.

If your engine is idling smooth, then the rockers aren't bad. Personally, I don't put a lot of weight behind that MAF sensor reading, there are many possible variables in why it might read lower. Chief among them, that the EGR valve could be partially stuck open or you could have an air leak from somewhere else in the system and the MAF sensor itself could be failing.

Their sensitivity declines over time and they should be replaced on occasion. On the TDI, they are much more critical to the operation of the engine, so an improperly functioning MAF will not be hidden for long. The CRD doesn't use it for general fuel mapping, so the same sensor could be failing for a loooooooong time and not be discovered.

Now, a bigger question - Have you replaced the timing belt? Certainly for the age, it is due, but if you aren't the original owner AND you can't definitively say that YES the belt and all the accoutrements have been replaced (like you have SEEN the old parts) then you should seriously consider having this done.

Conveniently... I'm the most experienced CRD mechanic in the country, having worked on more than 30 of these motors changing the timing belts, and I have a trip through NC planned in the coming weeks.

dennhop · **Posted:** Sat Apr 26, 2014 7:07 pm

I can 100% guarantee the timing belt was replaced just before 100k...I did it myself, doing waterpump, tensioner and pulleys at the same time. I'll have to double check the intake hose-last time I checked it it was still good. CAC hoses are good- Samco hoses about years old. I do wonder if my egr is stuck open, but I intend to see if it falls off one of these days, as I have the GDE FT Eco tune.

Edit:I need to update location...I'm in Indiana now.

geordi · **Posted:** Sat Apr 26, 2014 7:14 pm

Well... The EGR might be just dangling there, it may need a little bit of "encouragement" from a rough bumpy road to finally fall off... The Weeks101 Elbow kit will also make things very nice looking there and solve that problem permanently.

You will want to retain the water line from the head however, just run a rubber hose up and over to the Y connection and eliminate the metal pipe that drapes on the top of the engine.

CRD rocker arm wear...more info

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