Possible cracked block?

N2GN2 · Jan 1, 2016

They hold the valves better under boost and CP then the stock springs.

79jasper · Jan 1, 2016

Just the other day someone recommended some other valve springs that are better. Of course now I can find it.
Found it.

Comp cams
26056-16
Retainers
610-16
703-16

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superpsd · Jan 1, 2016

Lt.Dan said:
Does any body think that's a bad idea? I'm still just a little afraid that the block is cracked and im gonna spend all this time and money puttting it back together, to find out it didn't fix it...

I would hate to do all that work and find out the bottom end is at the end of its life. It's at 350K and been worked hard it sounds. I don't know if I would waste money on springs and studs if I was not turning the power level up. If you just plan to stick with a tune the own stuff holds it together without issue. A compression check before the tear down would have been nice information.

Arisley · Jan 1, 2016

If I had it that far apart, with those miles, I would at minimum, run a hone through the cylinders to break the glaze, and replace rings, rod bearings and main bearings.

Lt.Dan · Jan 1, 2016

Im torn between three ways,

1) put it back together with no machine work $500~, least amount of time, highest risk
2) pull it and machine and mag everything $1-1500~, + most time
3) pull it and buy a used long block and drop it in $2000~, slight risk of problems

Lt.Dan · Jan 1, 2016

Here's pics of the cylinder walls, they're off my phone, so I can't see them,I hope they are correct lol

Edit: the second one is upside down, sorry! These were taken immediately after the head was removed

m j · Jan 1, 2016

79jasper said:
Just the other day someone recommended some other valve springs that are better. Of course now I can find it.
Found it.

Comp cams
26056-16
Retainers
610-16
703-16

Sent from my SAMSUNG-SM-G890A using Tapatalk

I am going to look up what those are but these are the ones I used
COMP Cams Valve Springs 26120-16
COMP Cams Super Valve Locks 617-16
COMP Cams Steel Valve Spring Retainers 795-16

with stock valves and seals

installed within 10thou of advertised height so a little looser then the 155# seat

edit * those are a lot stiffer.

Lt.Dan · Feb 11, 2016

Well ive been super busy lately and havent been able to work on the truck since i last posted. It doesn't look like my work will be lightening up any time soon, so instead im giving it to my buddy that owns a diesel shop the next town over. He says hes going to send the heads to machine shop first to get magnafluxed, and go from there, hes classifying it as "head gasket R&R" and Is only going to charge me $1500 to get it back on the road, running and driving as it should, including head gaskets, head bolts, the whole nine yards. But, if the block is bad, or something major, we will reevaluate.

Im going to keep close to the build, and ill be sure to take lots of pics and keep updates on this thread.

Rico · Feb 18, 2016

I'm going through a similar situation in a way. After noticing that My truck was blowing white smoke on the freeway I pulled over and saw coolant coming out of the exhaust downpipe. So I removed the heads and had a machine shop freshen them up(cups, magna and valve job). $500. The heads are pretty heavy if the motor stays in the truck! Im putting about two hours a night into the truck after work now. Im replacing a lot of parts since the top half is open and hope it was a cup/gasket. Good luck!

benjamindurtka · Mar 22, 2016

Similar problem with my 7.3. When the engine was off and you put coolant in the reservoir it went straight into the oil pan. I was told by a few diesel mechanics that likely a cracked block since the system was not under pressure to cause it to leak from anywhere else. When I pulled it and took the oil pan off there is what appears to be remnant of the end of a rod and head in the bottom. Haven't pulled the heads off the old engine yet to see what it looks like from that angle.
Best of luck

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Rico · Mar 26, 2016

I'm not 100% sure but I think I had a loose injector

benjamindurtka · Apr 1, 2016

Bolt broken or loose? Running yet?

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Rico · Apr 3, 2016

I think it was just loose. Truck runs like a champ!

Charles · Apr 3, 2016

1500 degrees means nothing unless it's sustained. 2000, then you would need concern.

Looking at your pistons..... you NEVER saw any decent heat. Period. They would have at least 2 or 3 cracks coming out of the bowls, and they don't. I've never had an engine apart that did any towing with stock pistons that did not have cracks.... so consider yours babied.

Secondly, if heat had opened a path for coolant to reach the crank, I would look for the cylinder head to be cracked between intake and exhaust deep enough to reach the cooling jacket. Remember...... if you were smoking the world out then the coolant was NOT flowing straight to the crank.... it had to be running into the CYLINDER....

In my experience this is a cracked head, although it could be the block, that is usually catastrophic as cylinder pressure will push a nice window through the wall at that point.

The lack of cracks in the pistons deter me from thinking exhaust gas temperature. Even stock trucks that tow heavy will have cracked pistons.

Lastly, in my experience, you can't tow with an OBS and no coolant gauge. I think that's now your experience too...

If you hurt the engine, it was with coolant, not exhaust gas temp. Remember.... your pistons are aluminum, nothing else is... If an engine gets hot enough from egt to hurt the heads or block the pistons will show it. If the engine actually runs hot, the pistons might be fine (although getting a bit tight, lol) while the heads are warping and being destroyed.

Look at the heads between intake and exhaust for cracks. Clean the pistons are see if they really are without cracks. If so, that thing never saw egt.

On Edit:

I've never seen a 7.3 without beautiful crosshatch.... no matter how hopeless the blow-by was, lol.

Lt.Dan · Apr 6, 2016

Charles said:
1500 degrees means nothing unless it's sustained. 2000, then you would need concern.

Looking at your pistons..... you NEVER saw any decent heat. Period. They would have at least 2 or 3 cracks coming out of the bowls, and they don't. I've never had an engine apart that did any towing with stock pistons that did not have cracks.... so consider yours babied.

Secondly, if heat had opened a path for coolant to reach the crank, I would look for the cylinder head to be cracked between intake and exhaust deep enough to reach the cooling jacket. Remember...... if you were smoking the world out then the coolant was NOT flowing straight to the crank.... it had to be running into the CYLINDER....

In my experience this is a cracked head, although it could be the block, that is usually catastrophic as cylinder pressure will push a nice window through the wall at that point.

The lack of cracks in the pistons deter me from thinking exhaust gas temperature. Even stock trucks that tow heavy will have cracked pistons.

Lastly, in my experience, you can't tow with an OBS and no coolant gauge. I think that's now your experience too...

If you hurt the engine, it was with coolant, not exhaust gas temp. Remember.... your pistons are aluminum, nothing else is... If an engine gets hot enough from egt to hurt the heads or block the pistons will show it. If the engine actually runs hot, the pistons might be fine (although getting a bit tight, lol) while the heads are warping and being destroyed.

Look at the heads between intake and exhaust for cracks. Clean the pistons are see if they really are without cracks. If so, that thing never saw egt.

On Edit:

I've never seen a 7.3 without beautiful crosshatch.... no matter how hopeless the blow-by was, lol.

Thanks for your insight bud, I havent had any extra money lately so its been sitting behind the shop every since.

I agree with you i dont think i hurt the motor with EGT's, or atleast not bad at all, i do agree that it was a coolant problem. Im still having plans of sending the heads to the machine shop and have the mag-fluxed, and tested, Cups replaced etc. but then i think im going to put all my eggs in the basket and put it back together without actually looking into the bottom end.

If it runs, then im back in business and no worries, but if it doesn't, well then i guess the motor is coming out...

Rico · Apr 7, 2016

I had a shop take care of heads(cups, valves and flux) for $500

Lt.Dan · Apr 8, 2016

Rico said:
I had a shop take care of heads(cups, valves and flux) for $500

Did that include parts? Or did you supply?

PsdPullerJr · Apr 9, 2016

Charles said:
On Edit:

I've never seen a 7.3 without beautiful crosshatch.... no matter how hopeless the blow-by was, lol.

1st time for everything lol supposedly had 165k on. When I say it had or didn't have compression, it was on a stand with the glow plugs removed and only 1 installed and I spun it over by hand. If it got tight it had some compression to it, a few cyclinders didn't hardly slow me down. The one in the pic that didn't have compression had the cyclinder wall wore about .04, look at the ridge at the top of the bore.