Rod bearing wear question

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tomloans

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This is a new off topic thread started based on cracked Castech 706 head and coolant in the oil. That great discussion about 706 heads is noted here...



Here is the notes from Blackstone...

"There is coolant in this first sample. Potassium and sodium are markers for antifreeze in testing, and
both are high. Sodium could be oil additive depending on the brand of 5W/30 being run, but potassium has
few other sources than coolant. Bearing wear (seen at copper and lead) is high too. Note the levels of each
that the universal averages show as typical for the 5.3L Vortec after ~5,400 miles of oil use. Stick to short
oil change intervals (like this) and be alert for coolant loses and symptoms of a bearing problem like

knocking and low oil pressure. Proceed carefully."

Copper is 132 should be about 19 ( after 5400 miles and my oil only had 900 )
Lead is 81... should be about 5 ( after 5400 miles and my oil only had 900 )

Sooo... Do I replace the engine or replace the heads and hope bearing wear will stop and live happily ever after with this engine...?

I have no idea if the bearings will stop wearing out once I get the coolant out of the system. This is my question, will bearing wear stop once it has started? Anybody have any experience with this please...?
 

mattbta

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You likely caught yours earlier than I did mine. My hot oil idle pressure is 32ish by the cluster -- need to get a physical gauge on it. What does yours run?

Cam bearings are usually the ones that are impacted the most, regardless of coolant intrusion. Cheap parts, but have to pull the engine to install -- the tool is basically a long ramrod.
 

swathdiver

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This is a new off topic thread started based on cracked Castech 706 head and coolant in the oil. That great discussion about 706 heads is noted here...



Here is the notes from Blackstone...

"There is coolant in this first sample. Potassium and sodium are markers for antifreeze in testing, and
both are high. Sodium could be oil additive depending on the brand of 5W/30 being run, but potassium has
few other sources than coolant. Bearing wear (seen at copper and lead) is high too. Note the levels of each
that the universal averages show as typical for the 5.3L Vortec after ~5,400 miles of oil use. Stick to short
oil change intervals (like this) and be alert for coolant loses and symptoms of a bearing problem like

knocking and low oil pressure. Proceed carefully."

Copper is 132 should be about 19 ( after 5400 miles and my oil only had 900 )
Lead is 81... should be about 5 ( after 5400 miles and my oil only had 900 )

Sooo... Do I replace the engine or replace the heads and hope bearing wear will stop and live happily ever after with this engine...?

I have no idea if the bearings will stop wearing out once I get the coolant out of the system. This is my question, will bearing wear stop once it has started? Anybody have any experience with this please...?
If you are going to pull the heads, I would pull the motor and put new rings and bearing in it. If I knew the answer to your question, I MIGHT replace the heads and do short oil change intervals with samples sent for analysis. But wouldn't that soon add up to new rings and bearings?
 

rockola1971

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Run it until it pukes. Meanwhile get a core engine and do a full rebuild on it and install it when you can or just buy a long block. Core engines, heck a runner are cheap. THere are millions of them around. Car-Part.com is a database for salvage yards across the U.S.
 
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tomloans

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Run it until it pukes. Meanwhile get a core engine and do a full rebuild on it and install it when you can or just buy a long block. Core engines, heck a runner are cheap. THere are millions of them around. Car-Part.com is a database for salvage yards across the U.
that is what I am going to do.
 
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Mudsport96

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Yeah depending on your ability and parts yard availability, i would look for a used 5.3 or 6.0. Fix the coolant leak for now and just run it till she dies. Hell it may live longer than you think.
 

iamdub

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This is a new off topic thread started based on cracked Castech 706 head and coolant in the oil. That great discussion about 706 heads is noted here...



Here is the notes from Blackstone...

"There is coolant in this first sample. Potassium and sodium are markers for antifreeze in testing, and
both are high. Sodium could be oil additive depending on the brand of 5W/30 being run, but potassium has
few other sources than coolant. Bearing wear (seen at copper and lead) is high too. Note the levels of each
that the universal averages show as typical for the 5.3L Vortec after ~5,400 miles of oil use. Stick to short
oil change intervals (like this) and be alert for coolant loses and symptoms of a bearing problem like

knocking and low oil pressure. Proceed carefully."

Copper is 132 should be about 19 ( after 5400 miles and my oil only had 900 )
Lead is 81... should be about 5 ( after 5400 miles and my oil only had 900 )

Sooo... Do I replace the engine or replace the heads and hope bearing wear will stop and live happily ever after with this engine...?

I have no idea if the bearings will stop wearing out once I get the coolant out of the system. This is my question, will bearing wear stop once it has started? Anybody have any experience with this please...?

Add me to the list of "send it". I know of at least one engine with that same failure that had it much worse and it's still kickin going on three years later.

If your oil pressure was fine, it should still have plenty of life left in it after you repair it and run good oil. I'd say you basically shortened the life of the engine. So, rather than 400K, you might only get 250K-300K. You want an oil with a high sheer strength. If it were me, I'd run a 10W-30 full synthetic with a bottle of Lucas ZDDP. Or, look into the Rotella for gas engine oils. I run Rotella for diesel engine (T6 in a "custom" 10W-40 mix) for the high sheer strength and robustness of the oil. Supposedly, zinc (strong amounts in diesel oils) will kill catalytic converters but I've never found how true or how quickly this could happen. I don't have cats.

If you do end up wiping a bearing, you've only really lost a set of gaskets, head bolts and time. You can keep the heads and whatever other parts you replaced if they pass a thorough inspection. BTW, you might need push rods. Inspect the lifters and cam lobes when you remove the heads. Be sure you keep the lifters in their original positions, ideally in the trays so they maintain the same orientation.

I'm confident you'll have recovered from this little sting long before it actually craps out. After the repair work, run some cheap regular SuperTech oil for about half an hour (but always run a good filter) then change it for either another short run of cheap oil or switch to something good and run it for a normal OCI. I'd recommend another Blackstone analysis after that first long-term OCI.
 
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tomloans

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Exactly what I plan on doing. Run the oil about 20 minutes without pressure on it. Just idle. Drain and do it one more time. Drain then add my Castrol and drive it! I didn't mention ( and why this makes sense for me ), I have another 2003 Tahoe (this one is a Z71). If engine fails on this LT, I can save the heads for my Z71 when the Caltech's on her inevitably fail! :D No great loss this way. Just some time and parts.
 
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tomloans

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Plastigauge. Check tolerances and go from there.

Those numbers are in parts per million. High levels for a short time won't appreciably affect engine life. So what... You might get 400k instead of 425 out if it. Meh.
My thinking and hope as well.
 

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