Cracked head

The torque wrench will be able to tell you how much torque it takes to remove a head bolt now.

It will not tell you how tight the bolts were.

It will not tell you if the bolts were over torqued.

It will not tell you if the bolts were tightened in sequence.

It will not tell you if the head was warped.

It will not tell you if the block was warped.

It will not tell you if there was any old gasket on the surface when the head was torqued.

What you will probably find is a service facility that has become annoyed at your interference. I am sure that if that facility could do something to send your friend out the door with a perfectly repaired truck, they would have done it and not put him off with things that they knew would not fix the truck. No shop wants to redo the same job over and over again.

Instead, why don't you drop by with a big container of Dunkin Donuts coffee, and a couple of dozen donuts. If you try, they might try. What could it cost? $20?

Bob, I have had absolutely nothing to do with the tractor short of driving my friend
to PA to get it on 7-3.
No interference, no discussions, nada, nil, just a genuine concern for a friends
livelihood. When he told me about the excessive use of coolant I drew upon my
own experience, having had another close friend with a Ford Tempo where the
1.9L HSC head had cracked between the intake and exhaust valves. I called every
auto wrecking yard from Cleveland OH to Utica NY and they all told me the same thing.
The heads had a defect and there was a waiting list for the next available "good
head".
We ended up using what I would have described as a voodoo treatment.
A can of NAPA block sealer, It was about $8.99 at the time and we figured what the
hell, followed the directions to the letter, pulling the sparkplug to the offending
cylinder, which was #3, and ran the car for the 10 minutes as the instructions stated.
Flushed out the gunk, refilled and to my surprise it did the trick, I was completely
stunned, And it held until some 20,000 mi later when the car was wrecked.

So much the better. Remember "good cop, bad cop"? You get to play good cop. Stop by early one day and make them like you. Tell them how concerned you are about your friend.

The torque the head bolts were set to was lost when the engine was run. Many engines need to be retorqued after the engine has reached operating temperature. The tempo had torque to yield head bolts. tighten them with a torque wrench, then turn then further as measured with a degree wheel. Once they are tightened, they become stretched, and can never be used again. I personally do not think there is anything to be gained by questioning the torque on the bolts.

It sounds like the repair shop is doing the fair thing, and not charging your friend for the bad guesses. Is there any chance that the shop will replace the engine with a factory authorized remanufactured engine?

I agree with Bob C. If the engine got hot, the thermal expansion and subsequent cooling have likely altered the head bolt tension values to where any measurements are not likely to prove anything.

Most warranties I've seen carefully state a disclaimer from liability for consequential damages. Unless your friend has a seperate policy that reimburses him for down time, there isn't much he can do.

I'm sure the shop is already upset at the non productive work they must eat to set things right. Being nice to them as Bob suggests is a prudent suggestion. You'll get more with honey (or donuts) than vinegar!

Something else to bear in mind. That shop has acknowledged a cracked head. They might just as easily have blamed that on your friend for overheating the engine. That they admit it suggests that the company is honest and assumes responsibility for it's actions. That's not as common a trait as i would like to see and needs to be acknowledged. I suggest something far better than a box of donuts!

l.j.

I gave you a GA for the first half only of your post. Spot on!

If I could, I would give you a OT for the second half......as:-

If the facility became annoyed, thats their problem and they have seemingly paid the price for not doing a pressure check as a first step.......the most logical and correct thing to do.......changing cam shafts for a coolant loss is simply weird.....also the new owner has paid a price too, I am sure that he could get damages if he wished for the time loss he has experienced......

It may be that for what ever reason they rebuilt the engine for they corrected the symptoms not the problem the cracked head. Or the the damage in the lower engine caused the cracked head. Any way it was missed or not inspected properly. I doubt that improper torque would crack the head. Most likely result in a blown head gasket. It or the engine would have to be warp pretty badly for the bolts holding it down to cause it to crack. No one likes to do work twice and the second time not get paid for it. So most companys will send the heads out to be machined and inspected.

My experience with cummings engines is it may not be a cracked head at all just because their is coolant leaking into the valve cover dose not mean cracked head. Your other clue to me, "the white smoke at times" means to me their is an injector tube in the head that is not sealed. Cummings engines has copper tubes that are pressed into the head and has sealing rings on them, the injectors go down thru these tubes into the combustion chamber. The white smoke says that one of the tubes are not sealed good and at times the coolant is also getting into the conbustion chamber. The repair shop will have to remove the head send it out to a machine shop to have the tubes pressed out and new ones pressed back in. And tell your friend to make sure the repair shop uses new head bolts when they reinstall the head. As the bolts stretch when they torque them and reusing old bolts the head will not torque properly

I agree with the advice you have been given by others. You should know, however that a container of block sealer does not always fix a cracked head, and it is risky to count on that type of repair. The reason is that many cracks have a habit of continuing to propogate until checked. One way to stop a crack from propogating is to drill a hole at each end of the crack, ream the holes for tapered pins, drive the pins into the holes, then reinstall the head and use the sealer. Always check the block and the head for flatness and re-surface if there is any doubt. Be sure that the repair is at least supervised by a knowledgeable mechanic. Before I learned how to do these things, my boss would sometimes let me figure it out on my own. You probably don't want an apprentice learning at your friend's expense.

I may never need that fix but I do like it, so you got a GA from me.....

Whilst you are correct in mentioning how to prevent a crack from propagating, I would suggest that the crack is metal stiched.............using any form of crack sealant that is introduced into the cooling system is a backyard mechanics way of repairing the problem. or an emergency solution to get you home.

To ensure that you find the extremities of the crack it is always advisable to use a crack penetrant.

One also needs to be wary of carrying out hydrostatic tests on cylinder heads, many fine cracks only open up when the engine is at its optimum operating temperature and the crack can only be found by using magnetic crack detection, crack penetrant or ultra-sonic testing.

Hair line cracks in a head are hard to find in a rebuild if the rebuild was not done for an overheating problem.

Cleaning the heads will some time remove rust or sealer that kept the leak sealed.

Also like he said a bit of gasket left on the block or a damaged head gasket could be it.

Pressure test the cooling system while the engine is hot !!!!

Mobi,

Hi, Bud.

To add to your post, very few of modern highly stressed engines, particularly diesels, rely on a torque wrench to set high stress bolts such as cyl. head bolts.

Most follow a very precise protocol; pull it down to a nominal value with a torque wrench, ie 60nm and then 90 deg, and then ANOTHER 90deg. All threads and heads, as you say, very well lubed. I liked MOLY greases.

This method relies on accurately marking the bolts being worked and their angles. The bolts are stretched to an 'n'th of their elastic limit

I HAVE seen the results of mishaps. Mobile phone rang and lost the flow completely. result some bolts at correct setting and some not. Too much of a hurry to re-do the lot. The head bolts were at their limits. You can only set these bolts twice. They are then to be discarded. No money nor time for a new set of bolts. Long story short- the engine went out with some 'loose' head bolts.

Mobile phones were banned in my shops, and operations such as these were NOT to be interrupted.

Cheers,

Stu.

Hi, Stueywright!

I've always used the 'plus 1/4 turn' rule of thumb if I didn't have the manufacturer's spec re the torque values. But if I have the exact specs, I'm more comfortable using them.

It occurs to me that regardless of what's wrong with the head if the repair depot is willing to replace it the OP will probably profit by not having one with any kind of fix-up done to it at all. Having to bring it back again several times and finally spotting the crack, or faulty injector feed lines, or whatever it is that can be repaired is justification enough to do a replacement.

What is the composition of the tractor-trailer Cummins, and how easy is it to replace the heads on them?

Mark

What is the composition of the tractor-trailer Cummings, and how easy is it to replace the heads on them?

On this model it is a one piece cylinder head. But it was an engine rebuild so it all should be replaced by the warranty.

I had the same problem with ordinary car (sedan). The problem is that with a usage engine body and the head warp due to the temperature. Then when you replace the head (by the new one) the engine body is warped while the new head is not and the coolant is leaking no matter what you do. The solution is to machine the engine body so that it becomes flat to stick to the new head. Btw you MUST tighten the head screws according to the spec, otherwise your head might crack again. Good luck.

Everyone is forgetting that you could have simply had a batch of poorly cast or poor casting material that made the block. I had this problem with my 2000 Jeep Cherokee Sport head. I developed a hairline crack and similar to the poster's friend's problem I noticed I was losing coolant but at a much lower rate (smaller engine). Again, I checked the oil and no fluid was contaminating it. I figured a small leak in a line somewhere which I could live with. The crack finally fully opened up and I lost all fluid at once. At the dealership an observant mechanic noticed the hairline crack and when he lifted the valve cover off, there was my missing coolant. All over the inside of the valve cover.

I work for Chrysler/Jeep as a car designer, so I contacted some people at the warranty centre at our research facility. I found out that Jeep had switched the supplier of the cast heads from the US to China. There was a run of 100,000 heads which were cast with an inferior metal which weakened and was susceptible to cracks at about 60,000 miles. Needless to say, these heads were used since this cracking would occur after the warranty was up.

Moral of the story is, don't be to ready to blame your mechanic for car problems when it could be the design/engineering/manufacturing that could be at fault. We have designed obselecance into every car we build. Have been since the '80's.

Be kind to your mechanic and he will be kind to you.

UFG

High output diesel engines such as this are 'tempermental' in that the proscribed overhaul and assembly instructions must be followed exactly. A cracked head may be 'characteristic' of that engine type, or it may have other 'weaknesses' such as the copper tube for injector pass-through. Come-on guys

An engine re-manufacturing shop should be the next stop. It is obvious the present facility is searching in the dark. Sometimes things are very hard to find, but 'pressure test' of cooling system is pretty fundamental when the coolant is disappearing.

With this plethora of repair attempts, change-out of the defective engine seems proper and fair. 'Lemon Laws' may apply. It is not fair to expose the purchaser to additional lost profits from the downtime.

This is why many manufacturers fit their engines with individual cylinder heads. Don't stuff around with them, purchase a new or factory reconditioned head.

Quick send a check about $18,000 USD ...

But as stated somethings are not easily attributed on the newer chipped diesel engines. All is a very complicated stepped arrangement of sensors to a diagnosis make.

The point if I take it correctly is ascertain the capability of the shop used for repair. But this shop having the warranty needs determine a professional mechanic (not a parts changer) is required.....................................................................................Unfortunately the truck owner can not make such determination however may suggest it.

This repair facility has demonstrated a willingness to provide the necesary service. In my experience the method of approaching the cure is lengthy. The truck owner now has some experience and in future may avoid.

Just keep at it until the fix is in, there not else can be done.

Dead right!

The shop is at fault. Changing camshafts for fluid loss???? Crazy!!

Changing camshafts for fluid loss????

Crazy yes, so now he owns a rebuilt engine with a new camshaft...what's the rub?

"replaced them along with a cam that had had groves cut into them"

Not that crazy if the mechanic found a damaged camshaft, and replaced it even though the owner did not complain about it.

As it was (originally) written, they were changed as part of finding the fluid loss.

You only have to read the blog fully to understand why many were put on the wrong trail with regard to the camshafts!!!

Andy,

You are in this instance both right and wrong due unfamiliarity of commercial heavy truck diesel engine diagnostics.

If during the diagnostics of the fluid leak any other defective part were discovered it would be corrected whether or not it's correction effected the original complaint or not.

In my experience a shop may correct only what will get the truck back on the road in safe operating condition though not in perfect operating condition because the owner needs continuous income. If it is determined another load could be transported without incurring additional damage to the system in question or if realization is that the damage has been done but the truck may safely operate and the repair can wait until getting the unit to the home location is more beneficial.

I reproduce here what was originally written:-

At that time I told him it sounded like a cracked head, he took it back to the
dealer where he purchased it and they sent him to a repair facility that
honored the warranty for the rebuild that was done.
This started July 3, since then he's been to 3 different repair facilities,
he's had cams replaced, the turbo replaced twice within 2 weeks, etc.
All this work was done to honor the warranty and all he has been out financially is the time spent being repaired instead of producing income.

As you can read, it reads as though this was part of the search for a fluid loss, no mention was made at this point that they were found to be worn out and replaced for that reason only, as should have been done!

Furthermore, I was not alone in understanding the facts as presented wrongly, several others were also mislead.

Therefore I ask, are you implying that we are stupid or something? If so that was not very friendly! please desist from posting for such banal reasons as we were already completely clear on what happened once the original poster had corrected himself........as was anyone else with a modicum of intelligence!

Whoa up there Andy!

The following statement doesn't reflect my intent nor clear a confusion; note the underlined text, the correction was post #23 my reply was to post #29. What have I misunderstood?

Therefore I ask, are you implying that we are stupid or something? If so that was not very friendly! please desist from posting for such banal reasons as we were already completely clear on what happened once the original poster had corrected himself........as was anyone else with a modicum of intelligence!

First to you Andy. I am the one that brought up the replaced camshaft as being not so crazy when it was revealed by the poster that there were scores on the shaft. My reason for replying was because I felt that bwire had missed this information when he posted that it was crazy to have had a camshaft replaced , when the problem was a coolant leak. Please do not be offended by any of my comments.

Now to bwire. You are entitled to imply that I was calling you stupid or something. But I was just trying to point out the information concerning the scoring found on the camshaft, that you may have missed. So you can now start a raging tirade on my lack of sense, and courtesy.

This much I will say. I lack the good judgement to control my temper. When I am finally annoyed enough by a poster, I will usually ignore the thread. If I do get too annoyed, and write an offensive post. Everyone will recognize it. The thread about someone heating his house by converted hydrogen should prove that.

Now lets stand in a circle and sing..... We are the world, We are the children..........

Hello bob c,

Hah! My statement about the camshaft replacement was a sarcastic reply to Andy.

I suppose I'm not astute enough to realize any criticism was directed at me

I can't believe you guys are talking about supplying donuts and greasing palms to get the repairs done right!

First of all, the guy clearly states that the owner/operator has been to 3 different repair facilities. This is not one frustrated shop we are talking about here and all of the shops were or will be compensated under warranty. (Honoring the warranty simply means that they are willing to submit a claim to the insurance company that issued the warranty to get paid for their work)

Second, the mechanics working on the engine are probably paid book labor rate and have no desire to have it come back on them.

Third, the warranty is probably an insurance policy purchased by the dealer and the insurance company is the one out of pocket for the repairs, not the repair facility (unless the insurance company can find a loop hole).

Fourth, don't mess around with the bolts! This may void the warranty (loop hole).

As has been stated, the likelihood that you will ever know if the bolts were torqued correctly is slim to none. Just try to get it right before the warranty runs out, K?

If there is any question on whether a block, head, or any other stressed component has a crack, a shop that is worth working with would magnetic-particle inspect it. This is especially true of diesels with high combustion pressure.

Inferior castings are more common than you may realize. Work with a reputable supplier.

I can't think of any reason to mess with the cams for this issue unless something else unrelated is going on.

Never re-use head bolts, even if they are not torque-to-yield. Chase the threads in the block.

An ultrasonic test is easier and quicker.

gentlemen,

greetys, i am the owner of the 2000 pete with 475 Cummings. when i bought the truck i (we) were told the truck had alot engine work done and that i would very happy with it. left dealer bobtailed to NY and then to MN. there i left with a trailer, well as the story went it used way more coolant than a truck that traveled less than 10000 miles could ever possibly have expected to.

truck was returned to a cummins shop they found leaking hoses after pressure testing radior over night, replaced them along with a cam that had had groves cut into them, the turbo, and the jakes (had worn springs). when value cover was removed saw a drop of coolant (green not gray) in oil in top of head. tech assumed it fell in there from where i don't know. did not pressurise. left there went to FL and returned consumed alot of coolant. took it to a pete dealer with same complete. they found turbo had oil on both sides, replaced. cac had oil in it. removed, drained,pressure tested discovered leak. bottom rad hose leak around clamp that had been replaced. checked all hoses assuming coolant must be leaking out exterly. itold them that i did nt see any signs of coolant on any exterior parts of the truck. well off again i go. third time in shop they found leak in head same spot where i saw it in cummins shop (what a surprise). have since removed head, pan, pistons, cams. am going to replace head, cam, crank bearing, turbo. hopefully this is going to get me down the road for awhile

First mistake; taking it to different shops. Each shop starts from scratch with a different theory on what is wrong. They then try what they know fixed the problem with another engine in the past when they can't find the problem quickly, hope it works and give it back to the customer. This means you can go to every shop in the world and not get it fixed.

Find a good shop and stick with them, then with a mixer of logic and trial and error even an average mech will find the problem. Like all trades 80% of mechs are average or worse 15% are good 5% very good. That top 20% because of lousy wages and conditions are the guys who are first to leave poor workshops so don't expect difficult things to be fixed first go.

Diesel engines require special coolants to prevent cavitation damage to the cylinders. The cavitation is caused by ultrasonic sound waves generated by the intense pressure of the diesel combustion.This erosion was once thought to be caused by electrolysis, but the true cause is now known.Is it possible that the engine suffered from previous cavitation damage before rebuilding? This is very hard to detect, and may not have fully penetrated the cylinders at time of ovehaul, but completed the damage later as the damage progressed.Replaceing the coolant with regular coolant, without the special additive package could have made the problem worse.

Just a thought for consideration.

HTRN

One of the "major" engine manufacturers has a greater problem with this than the others, for reasons that, I know not.

Uneven heat