The original cracked head concerns me. What was the history that caused it? Overheating? I would expect any smart insurance person to ask questions about this.

The first "new" head should have had all new valves etc, so if it did, the first replacement head should not have contributed to the 70 mile failure unless it had a fault, or was incorrectly installed. not an act of God.

The 'tick' sound when you got it back concerns me. Maybe a valve hitting a piston? Suggesting bad cam timing or a piston hitting the head? Wrong piston (not so likely).
I would be very concerned about reuse of that motor. It has had 2 unresolved major failures. Unless some one went right through the motor ( complete rebuild from sump to valve cover, fan to flywheel) I would not touch it. No one knows what other small near failures are now in the motor waiting to go bad.

It sounds very likely that the cam timing has been set wrong and with the stretching that occurs when the motor runs at speed there has been a serious collision internally. What were you doing when each failure occurred? 75 mph on the freeway?
A complete replacement motor is the only option, as to who pays ~ have fun !!!!

__________________
Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Well at last a little understanding by me of why some want to do god's work. I always wondered about their motovation before.

Have you been able to get the mechanic on the phone about this new failure?

These acts of god as the shop called it do happen, but that does not change the fact that the engine blew up again, and immediately after it was supposed to be rebuilt.

I had a situation once where I was replacing the glow plugs on a 2000 TDI for a customer, and the threads were destroyed on one cylinder since the glow plug had been cross threaded to begin with. I went in to carefully chase the threads of the hole, but I broke the tap off!
I pulled all the little pieces of the tap out that I could get, but I was not completely sure, so I had to pull the head and inspect the cylinder.

I come to find out that at some point in the cars life, the turbo had exploded and damaged two of the pistons and cylinders. It had been repaired by the dealer, who had picked all loose debris out of the cylinder, left the pistons in with dozens of little hot spots, charged the guy for a new head and new pistons, and sent him out the door.

When I found all this existing damage and showed the owner, he would not believe that it was not me who had caused this problem, even though the car had not been run after the tap broke off.

We ended up replacing his timing belt for him, and putting it all back together with new parts for free. We left the damaged pistons as well, we just redid all upper end stuff. The moral of the story is that **** happens, and these guys will have to be responsible for this new failure, BUT, it may not be their fault as they say. Does not change what it owed to you as the customer.

The fault could and probably lies with the machine shop, who may have used old stuff, or mis installed or machined this or that. The auto shop would receive a machined head and simply install it correctly with the assumption that the machine shop knew what it was doing. Many times, a mechanic who knows everything about how to put the engine together, may not be qualified to double check a machine shops work, and why should they double check?
Part of using a machine shop is farming out the labor to an expert. Its time involved as well. When you are sending something out to a shop, you are paying for the luxury of not having to put that time into that part of it. There is no point if you then have to go completely through it when it returns. They probably gave it a once over looking for bends, breaks, or damage.

A head is as complex as a transmission, and arrived as one unit. When a replacement tranny arrives, the auto shop does not take it apart to check tolerances, and does not really inspect it for anything other than large obvious problems. They probably got just a screwed as the vehicles owner.

My theory is that the machine shop used the wrong specs for this head a couple times.

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This post brought to you by Carl's Jr.

I visited the shop yesterday to see what was going on and discuss some of the topics brought up in this thread.

The mechanic had the head off the engine and had disassembled it with a representative from the machine shop present. The mechanic showed me the head and we looked at the engine. There were no signs on the top of the pistons that would indicate they had been hitting the valves. The piston tops were a smooth almost semi-gloss black.

The #3 exhaust valve moved freely up & down. This is the valve that had the shattered lifter (the lower portion of which was jammed in the cylinder head). The #2 exhaust valve (I believe) was bent slightly (preventing it from moving easily) and its lifter had some light scoring (on the top). The cam broke in two places (both breaks near the damaged cylinders).

I don't believe all the valve components were replaced during either rebuild. I did request and received an new cam chain for the second build. Lifters not involved in the damage appear to be in good condition (no scoring on the sides or top).

So far, no word from the machine shop. The mechanic swears he checked and double checked everything (especially on the second build) and can find no errors in his work. He also said if he could see anything wrong with the work done by the machine shop, he'd point it out. I'm dubious concerning these last two observations. So far I'm being told the lifter failed, really bad luck.

I again mentioned the "tapping" noise the engine exhibited from the day I picked it up. But this is pretty much being ignored. Maybe someone out there can help concerning this noise. It sounded much like a loose tappet but seemed to come more from the lower portion of the engine than from the valve cover. It was barely audible from inside the car and was best heard by rolling down the window and driving past something that would reflect the sound back at the car (a building, jersey curb barrier, etc.). It got louder under a load but never sounded like a real problem until seconds before the failure. It was nearly inaudible at an idle.

Also, I'm assuming that if the valves came in contact with the pistons, there would be obvious marks on the pistons, right?

Thanks for every one's input on this. I'll keep updating this thread with my tale of woe.

Im not a fan of junk yard lawyers but this is a good case for one.

If they (the mechanic and the machine shop) dont respond by Tuesday
with a statement they are going to R&R motor with a NEW motor, Id
be having the JY legal beagle send them a demand letter. Any court
action would of course INCLUDE your JY lawyer costs.

They screwed up. OUR motors are not cheap. THEY need to fix it and
do so now and properly.

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1985 300D 198K sold
1982 300D 202K
1989 300E 125K
1992 940T

"If you dont have time to do it safely, you dont have time to do it"

"The democracy will cease to exist when you take away from those who are willing to work and give to those who would not."

The problem here with acertaining the actual cause. It might be impossible. All that may be visable now is the residual damage.

It may be almost impossible to tell what went out first. I would think without actually knowing that a lifter shattering is not only very unusual but I am trying to remember if I ever even heard of that type of failure before. . Certainly without something else failing first if it were to occur. It takes substantial force.

If the cam is not broken ahead of the number two valve how did the number two valve get bent? So I assume the cam is either broke ahead of the second valve as well or the engine has jumped chain timing during the event.

This event could have occured by the towers that support the cam not being in line accuratly bearing wise. Or more likely there is a specific sequence to removal and installation of the camshaft towers pecular to the 603s that may not have been followed correctly..

After putting the towers back on the engine I would want to hand spin the cam to at least have an indication there was no binding prior to installing the rockers. It also may have been damaged at the time the towers were taken off the head.. I doubt if anyone checked the camshaft at any time for any runout. I guess what I am trying to state that if you do not have the service information or knowledge on working on the 603s you could damage the camshaft.

I would not discuss this with the mechanic or the head rebuilder. Your lawyer could prevail in discovery by asking the mechanic or machine shop the sequence of or methology used in removal of the cam and towers.

If whoever removed the cam etc does not know the required sequences you have them.They are probably very confused themselves about what transpired. Not an act of god without following the correct methology. Best of luck.

cdavidson,

"Bob" And "Barry" both have your answer(S).

Do not get involved in the "Finger Pointing"...
That MAY occur between the Mechanic and the Machine Shop.

(or, they MAY elect to BLOW you OFF, COMPLETELY...Which is what's Happening with "Too Bad ,So Sad about your Lifter")

These guys KNOW they've "Bought the Farm" [Your New Engine] and are
trying to "See" if you're gonna walk away with a "Fairy Tale" in your teeth.

Demand Letter from Law Office ('Cost you less than $100.00) to BOTH!

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'84 300SD sold
124.128