Blown C12 - The Rest of the Story

[reymore]

The destruction of the C-12 in our 2001 Safari Panther with 41,155 miles, happened on August 28, 2009, throwing the #3 rod through the side of the engine block. We had just come off the Continental Divide at Monida Pass on Interstate 15. This is a long, straight grade reaching 6% in several places. Naturally, there was heavy use of the Jake brake. The C-12 waited to throw the rod until we were going through Idaho Falls at about 55 MPH. The official failure analysis by Western States CAT was that the #3 rod bearing spun and caused stress on the rod bolts which broke. Why did the bearing spin? I have been trying to find out the root cause of failure since then.

I was told that it was not caused by operation or maintenance, and the oil analyses from both CAT and Amsoil supported that finding. I used Amsoil high-performance diesel oil. That only left a latent defect, which Caterpillar has continued to deny. The engine was out of the time warranty. We had purchased the coach from Paul Evert on Jan. 29, 2007 with 11,551 miles on the odometer. There was no history of use or maintenance. I do suspect some air filter maintenance issues. When the engine was disassembled, the turbo showed evidence of ingesting foreign material, and I know it did not happen during the 30K miles that we put on the Panther.

Previous to the Panther, we bought a new Zanzibar and put over 70,000 miles on its C7 and Allison 3000 transmission.

Without going through all the sordid details, there are issues and information that I believe should be passed on to motor home owners with Caterpillar engines and Allison transmissions…especially the C12 with the Allison 4000:

1. CAT has not come up with a credible cause for the spun bearing on just the #3 rod. I believe now, more than before, that there was a problem with the rod bolts – either physical properties or over/under torque. Caterpillar would not let me have the bolts, nor did they do any analysis. The compromised rod bolts were overstressed by the overspeed braking horsepower.

2. 2100 rpm is the limit for the C12 with the Jake brake applied. From the Caterpillar Operation and Maintenance Manual, “Operation of the engine over 2300 rpm will cause the Electronic system to activate the CHECK ENGINE lamp, indicating engine overspeed.” It does not! The Caterpillar ECM is “hard programmed” for the lamp to come on when 2600 rpm is reached for 1 second. At this time, an overspeed fault is recorded in the ECM. The ECM will also record all 6-minute intervals of 100 rpm for the life of the engine. (Our blown engine had recorded one 2200-2299 rpm interval coming off the grade on I-15 and “most probably exceeded 2300 rpm for less than 6 minutes.” The only way a driver knows they are in the overspeed range of 2100 to 2600 rpm is to watch the tachometer. Mark the limits on your tachometer and pay attention to it when descending a grade.

3. The Allison manual, as well as Allison technicians’ presentation at RV rallies, states that the Allison transmission will save the engine from overspeed. Our previous Safari with the CAT C7 and Allison 3000 would do that. Our Allison 4000 will not, nor will any other 4000, unless it has been programmed to downshift to 5^th gear. 2500 rpm is the transmission ECU’s programmed upshift point. (There is no data link. When the Jake brake is applied, the CAT ECM sends a signal to the Allison ECU to downshift.)

4. Caterpillar claims that the primary failure mode for the C12 from overspeed is valve/piston failure when the Jake is activated. I have heard from several RVers who have destroyed their engines because of “valve problems.” Caterpillar claims they have used the stock C12, with a different head, for racing, and turned 3200 rpm. They also claim there are no known problems with bearing failure, which lends credence to my claim that there was a “quality” problem and latent defect.

It has been over two years since the failure, and I have accumulated a rather large file of verbal information, documents, and letters for the book I may write. I would have stopped digging for information a long time ago except it cost us $33,140.20 for a remanufactured engine. In addition, Caterpillar and Allison kept challenging me with technicians and managers who have been condescending, evasive, and incompetent. I don’t say that without chapter and verse that show it. My working background has been in manufacturing and quality while serving on many trouble-shooting and failure-analysis teams. I am a retired civil servant with 39 years; have an additional 6 years with a major aerospace corporation; and continue to be on call with an engineering firm…and too old to be bashful about it.

The Reymore family is quite large, with several of us involved with Caterpillar equipment. One of my nieces, a professional driver, summed it up well: “Your problem, Uncle ****, is that you have the best equipment and the lousiest technical support.”

I still love the way the C12 and Allison 4000 runs and works.

[dickandlois]

Reymore!

Great write up.

It would be interesting to know what the Connecting Rod,Cap and number 3 rod journal looked like. With magniflux ,electron scan and annealing measurements. The other issue that is up in the air! what did the bolts look like,over torqued or just defective when manufactured.

Work on production line quality is always challenging, working with multiple suppliers and trying to keep good parts inspection in the parts room keeps life interesting for sure.

Thanks for sharing, I learned a good deal.

R.M.

[reymore]

R.M.

Thanks for the reply. I believe that the operational information is pretty important for us RVers and it was like pulling hens teeth to get it.

I have pictures I took "the morning after" that show the rod sticking through the side of the block and still attached to the top of the piston. The bearing and rod cap were missing. One rod bolt was broken under tension flush with the rod. The other bolt had its head sheared off and was bent. There were heat marks on the rod that indicated that the bearing had been spinning. The rod cap, pieces of the bearing, rod bolts, and aluminum piston skirt were in the pan. The failure analysis by the Western States truck supervisor was that the spun bearing and bearing clearance overstressed the rod bolts. That is far as he could go.

The official failure analysis that the Caterpillar "engineering team" just came up with is so ridulous and dissjointed that it took two pages to challenge it. They even set up a meeting with us to discuss their analysis. The West Coast Product Support Manager repeated their flawed analysis with condescension and salesman tactics. A local dealer rep was present and I don't think he believed it either. That is when it was time to publish some of this information.

I am not as bitter as I am annoyed,

****

[dickandlois]

Every manufacture has tolerances they work with and on occasion, two plus or two minis side parts get put together that results in a dud.

With the serial number it would be interesting to see the production run info. that went with the engine in question.

Not being familiar with there production protocol,where (are) the Rod and Journal bearings clearances gauged during production?

Again thanks for posting the information. Your on the West Cost and I'm on the East side,but maybe some day we will meet up.

R.M.

[planocat]

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[backtrail]

Reymore,

Thanks for the heads up, it was surely an undeserved result of what sounds like a well care for and maintained coach. You have succeeded in putting me on high alert or maybe better put a very concerned C12 operator.

Last year we purchased a 2000 Beaver with a Cat C12 and a Allison 4060 with 37,000 miles on it. Since then I have been completing a maintenance update of the rig, mostly with the motor, trans, brakes, and all the systems service that over the years had been ignored. One of the services was to have the valves adjusted, which I believe is part of a required 30,000 mile major service.

When we bought our Beaver I had Cat pull the records of work done, nothing recorded, but there was two recalls that had not been addressed. But of course since the warranty period had passed we couldn't get it done, one of the recalls had to do with the Turbo.

I was wondering did Cat explain what they found to be the foreign objects?

One of the first things I tried to do was to bring myself up to speed as to the C12, the Jake and the Allison how they worked and procedure for operating. I have been reading all the material I could find on this site, the Beaver Ambassador Club, http://beaveramb.org/ and the Cat RV owners web site, http://www.catrvclub.org/

But it sounds to me that you already had that knowledge, so what can I do to prevent this? I had the Allison programing checked and it is set to down shift into 5th and I am aware of keeping the rpm in it limits, but is there any type of preventive steps I can take or should I just start praying, a lot.

Also any further thoughts or info would be appreciated by me and the rest of the C12 owners out here.

On a side note, during our search for the right rig, we came across the same model Beaver with a rebuilt C12 with 49000 miles on the rig, the motor had 2500 miles on it. The main thing is that I do remember is the following; Cat stated the reason for the blown motor was the result of a foreign object entering the Turbo, in this case it was water entering the air intake, the result was the number 3 piston sucked a valve or close to it, (I am not sure of the details). The owner claimed it was because the previous owner power washed the rig and forced water into the air intake and when bringing the coach home it blew. The cost was around $35K. I wasn't sold on the story so we passed on the purchase.

But when I read your story it hit closer to home.

I do hope your days on the road will be much smoother in the future. Thanks again for sharing, I appreciate it.

Regards,

Bill

Backtrail

2000 Beaver Patriot Thunder

C12, Allison 4060

Cool, California

[reymore]

Bill,

Sounds like you have covered yourself. I am always suspicious when something like an engine has been replaced.

The one problem we had with the reman was the faulty thermostats that were in that engine and caused a temperature fluctuation. I’m sure that they were the cause of a blown water hose that again left us on the side of I 15 for 3 hours before the tow truck came. I believe that it cost Western States nearly $3K for the tow and fix. After CAT technicians had me running around chasing bad connections and grounds, Bret was insistent that I replace those “new” thermostats. Seems like Bret and several mechanics knew that these faulty (Cal Therm) thermostats were being sold and used, but CAT was silent about it. I never was reimbursed for that fiasco.

It made me sensitive to the number of plastic radiator tanks made for Ford F8 trucks, which I have had to replace. As suggested by one CAT RV blogger, I replaced the 14# cap with a 5# cap and so far it is working fine. Don’t know if Beaver used the same tank.

Yes, prayer helps a lot. Prayer keeps me from being bitter! I haven’t resolved the agitated thing yet.

It has taken me a couple of weeks to cool down after the Caterpillar Product Support guy called for a second face-to-face meeting at Quinn CAT. A Quinn TEPS Manager attended both meetings and thankfully he was pretty quiet. I don’t think I could have contained myself with one more antagonistic bully.

Things started to get ugly when I started writing to Steven Wunning, President, Resource Industries Group. I ask to talk to someone in Caterpillar that could rationally discuss the facts surrounding my blown C12 and that so far I had encountered vagueness, incompetence, and condescension. I was naive to believe that there was integrity somewhere in the Caterpillar organization.

After the first meeting with the CAT guy and Quinn Manager, I let them know that I was in complete disagreement with the “failure analysis” presented by CAT as noted below. During our discussion, I showed them the oil analysis taken prior to the first oil change on the reman engine. They got alarmed and noted that the silicon level was 12 ppm and that I probably still had a problem with a breach in the air intake system even though it was not flagged as a problem in the analysis. When I got home I found out that the limit was 30 ppm and the two analyses on the blown engine from CAT and Amsoil were 14 ppm and 12 ppm respectively. There never was a problem with the air intake system since I owned the coach and there still is no problem.

When the CAT guy (under his name is “CAT Truck Sales” but he took offense to my statement that he used “salesman tactics”) called for the second meeting, I asked him what we had to talk about. I was led to believe that maybe we were going to have some rational dialogue. All he would do is recite the tired old warranty clause and would not discuss the validity of the CAT failure analysis. When he boastfully let me know that he was a mechanical engineer and trained in failure analysis, I kind of lost it. I suggested he had wasted an education, his time, and now my time. I don’t think that we are friends anymore and here is the CAT failure analysis that has caused this mess:

October 3, 2011, from Mark Rieter, Field Service Coordinator

“The picture provided by you of the broken rod does indicate that one rod bolt suffered a tensile fracture and the other bolt a bending fracture. The picture also shows fretting of the mating surfaces between the rod cap and the rod indicating the joint had been run with excessive clearance. The upper bearing shell still in the rod shows lack of lube due to insufficient oil film, also a result of excessive clearance. In conclusion, the rod bolts broke after the debris that entered the engine caused extensive in-cylinder damage resulting in a ventilated block. Without a cylinder to guide the piston and rod, it thrashed about the resultant debris until the rod bolts failed (pulled apart) as noted in your most recent photo.”

The rod was not broken; the upper bearing shell was not in the rod…it was in pieces in the pan; and from what I could see through the hole in the block, the cylinder was still there. I guess “ventilated block” is fancy for “broken.” The whole paragraph just doesn’t make sense.

November 15, 2011, from Greg Gauger, General Manager, Large Power Systems Division

“First, I understand you are the second owner of an RV equipped with one of our C12 engines…..thank you for purchasing a vehicle powered by our engine. Secondly, I regret you’ve had an issue with the engine and that we have not been able to resolve it to your satisfaction. I have reviewed the letters you’ve sent from December 2009 to the most recent letter received last month. I have also reviewed the responses to each of your letters from our product support team, including Cat dealer and factory representatives. I understand there have been teleconferences between you and our team regarding this issue, as well.

With this background, I reviewed photos and failure reports from the failure you experienced with our C12 engine, including the block, piston, rod, bearing cap and turbo. Looking at the evidence and in talking to my engineering team, it is clear to me there is damage to the compressor (clean air) side of the turbo that subsequently generated the debris necessary to cause a piston seizure, rod breakage and ventilated block. These are all typical cascading failures that occur when the turbo compressor is damaged to the extent seen. Conversely, if failure had initiated with the piston, rod, bearing or cap there would have been no damage to the compressor wheel as there is no path for this debris to enter into the compressor side of the turbo. Lastly there are no known pre-existing issues related to bearing or rod bolt failures on C12’s of this vintage.

We are highly confident in this analysis. What specifically caused the damage to the turbo compressor wheel is unknown, but most likely some form of debris was introduced from the air cleaner side of the engine at sometime in its life, possibly before you purchased the product. I see no indication of a defect in material or workmanship on behalf of Caterpillar. And regrettably, this is not a warrantable failure.”

Again, there was no “broken rod” or piston seizure. The block had a big hole with the rod sticking through with the steel top of the piston attached. The aluminum skirt was broken up and in the pan.

Brett, Suzanne, and anyone else,

If you can make sense out of this, and make the connection between a spun bearing and a seized piston (which is not evident), it would really be appreciated. Otherwise, my C12 had a latent defect in the #3 rod bearing assembly that caused the bearing to spin when perturbed by the overspeed load while the Jake brake was applied. Running with a rod bearing spinning will eventually break something in the lower end. Caterpillar hasn’t got the integrity to accept any responsibility.

Thanks for listening,

**** Reymore “And the truth will set you free”

[MichaelS]

Just picked up on this thread. Interestingly this engine in its original guise in the marine world, 3196, was the subject of a class action in the US in the 90's on into the millennium, which also covered the C12. The problem then was with the aftercooler, allegedly, but there were many reported catastrophic failures involving complete rebuilds. Something weird happened, the action suddenly died and the guy who started it went silent! I think there is more to this engine than meets the eye, but I doubt CAT will ever admit to it with thousands upon thousands out there!

Michael Slater

2008 CC Allure, with ISL 425

(2 3196's in my boat both subject to rebuild under warranty!)