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How?? burned through piston within hour of startup...

oceanobob

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Jun 13, 2010
Messages
751
Location
oceano california
Occupation
general contractor
This business with diesels and coolant has been impre$$ed upon me .... what little experience I have but the diesel engine mechanics have said
  • a little bit of coolant will ruin the oil.
  • If it gets into the combustion chamber or cylinder vicinity it causes consumed pistons rapidly.
On a gasoline engine it seems to not be such a demising factor. Total believer in the pressure test of the cooling system on a diesel cooling system to prove integrity, especially since I have learned how the head gasket and/or liner seals leaking can cost big money and down time.
 

Truck Shop

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Dec 7, 2015
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16,548
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WWW.
I debated posting this photo of one of our Series 60 14L that was rebuilt by a Freightliner dealer in Idaho. It only had 20,000 on it when it let go on a hard pull up Cabbage Grade I-84.
It was under full boost when the coolant system pressurized exploded the side of the radiator and grenade'd. Covered under warranty it determined to have three low liners in it by the dealer
who warranted the engine with a full reman. One of our tractors. Shrapnel she is.

image1 (003).PNG image2 (003).PNG image3 (003).PNG
 

Tenwheeler

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Dec 15, 2016
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870
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Georgia
I meant my post was before, fat fingers or head. Thanks for being nice on the reply. I am not contradicting you just questing because I do not quite understand. My thoughts are that engine has been ran hot. Weather from a cooling system problem and or excessive fuel - timing. Then the cylinders with the hot spots in the engine and or with bad injector spray patterns burn the pistons?
 

Tenwheeler

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Dec 15, 2016
Messages
870
Location
Georgia
I meant my post was before, fat fingers or head. Thanks for being nice on the reply. I am not contradicting you just questing because I do not quite understand. My thoughts are that engine has been ran hot. Weather from a cooling system problem and or excessive fuel. Then the cylinders with the hot spots in the engine and or with bad injector spray patterns burn the pistons? Is it possible the engine could have a timing advance problem. Does not do the things I associate with incorrect timing but ends up a few degrees advanced on the top end. Not enough to sound wrong but enough not cause heat?
 

Wes J

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Jan 24, 2016
Messages
649
Location
Peoria, IL
If you've ever experienced molten aluminum hitting a concrete floor, you know just how violently hot aluminum reacts to the tiniest bit of moisture. I used to work in an aluminum foundry. When a crucible or mold ran over and spilled on the floor the guys would just take off running and deal with the carnage later. Needless to say that floor had a lot of patches!
 

wrwtexan

Senior Member
Joined
Feb 5, 2011
Messages
558
Location
Cooper, Texas
Occupation
Indy Farm Wrench, heavy land clearing, rancher
I finally got to dive into and found I am ONE pump tooth off. 20190325_233449.jpg 20190325_230610.jpg

How this happened was I already had the head on but the front timing cover was still off. Not having a crank alignment pin that I have been able to find, I had the alignment marks for the cam so I believed perfectly bottomed in the crank gear valley. I then used a timing hole through the pump drive hub which would align with a hole in a tang on the back side. This saved trying to get 4 super tight torx screws loose holding the drive gear on as others had already stripped elsewhere...

The flywheel pic is where #1 TDC is in relation to where the pump is supposed to be at TDC. Piston is coming up where pump is at TDC mark.

Now for the $$$ question, would this amount of off and advanced timing be bad enough to do the damage done in such a short amount of unloaded run time?
 
Last edited:

wrwtexan

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Feb 5, 2011
Messages
558
Location
Cooper, Texas
Occupation
Indy Farm Wrench, heavy land clearing, rancher
Doing a eyeball angle check with an angle finder, it appears to be around 20 degrees off. IH 414 and 436 Bosch AMBAC 100 pumps are pointer set 18 before TDC. I must assume these Bosch pumps are internally advanced with the timing mark set on zero?
 

wrwtexan

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Feb 5, 2011
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558
Location
Cooper, Texas
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Indy Farm Wrench, heavy land clearing, rancher
One last thing to add, on original teardown after nearly 10K hours, #6 piston had some crown edge damage to it, similar to current #6 but on the opposite side. Could this have been a perfect storm of an underlying fuel problem that was exacerbated by the advanced timing?
 

funwithfuel

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Mar 7, 2017
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5,519
Location
Will county Illinois
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Mechanic
Too much advance will consume everything. I once in frames an old R model Mack. Everything was fine. Customer chose to not repair the leaking injection pump. A week later it's back, destroyed. Long story short, took it to a wrecking yard and had them put on a used pump. iirc , it was 16 or 18* hot. The best part was this yahoo tried to sue us. We wound up repairing the carnage and parting ways for good.
I misread what you had posted. I thought it said the pump was not disturbed.
 

Wes J

Senior Member
Joined
Jan 24, 2016
Messages
649
Location
Peoria, IL
On that engine.. the engine is set to TDC & the advance is set in the pump..

So this means when the pump is advanced we are getting 40ish degrees of timing advance? Yikes :eek:

Perhaps worse, at full load we're stuck at 20 degrees of advance.
 

wrwtexan

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Joined
Feb 5, 2011
Messages
558
Location
Cooper, Texas
Occupation
Indy Farm Wrench, heavy land clearing, rancher
Owner took head back to Trinity Casting and they were surprised to see it back. After explaining what had happened, he was told that kind of damage should have happened over several hundred hours, even with the advance, not in less than one. Their opinion is most of the damage is from 2 failing injectors. I got the set into my fuel shop this morning and hopefully will get a prognosis on them soon.
 

Twister

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Sep 20, 2017
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24
Location
Mid central
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Field Mech.
I have seen this on a 4 cyl. power-tech engine that was in a air compressor. Started great no exhaust smoke and no abnormal combustion noises. Originally had the fuel injection pump off for repair, pump drive gear was moved around to retrieve flat washer that fell, when removing the retaining but. Bottom line is don’t drop nut or washer. When you have gear puller in place to pop gear loose, DO NOT remove it. Puller in place will prevent drive gear from getting out of mesh of the gear that drives it. Had to remove front gear case to retime the injection pump gear. This engine ran for about 45 minutes, then we shut it off. Then when we tried to restart it, it wouldn’t restart due to low compression, because of the piston crowns were damaged simular to the pics above. I never would have guessed that moving that gear out of mesh with the other would have caused this, especially the way that engine ran and sounded.
 

wrwtexan

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Feb 5, 2011
Messages
558
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Cooper, Texas
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Indy Farm Wrench, heavy land clearing, rancher
Same here Twister. I would have thought it would have sounded way different being that far off time.
 

Randy88

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Feb 2, 2009
Messages
2,149
Location
iowa
We always have pump and injectors checked over every time an engine is pulled apart, even with a few hours on them, to have them bench tested and they find nothing wrong is really cheap insurance for peace of mind in my opinion.

In all the engines we've ever overhauled and had the pumps and injectors checked over, only a few ever came back where they didn't find a thing wrong with something fuel related, even with a few hundred hours on them, if I didn't make a mistake reading your post, this engine had 10k hours on it?? if that was the case the fuel system would have been the fist thing I'd have sent in to be checked over, with this low sulfur fuel today, I'm not sure I've had any engine fuel system make it 10k hours without an issue of some sort, especially the injectors.
 
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