Much better oil pressure after oil change.

[Rocket Man]

The reason colder climate oil recommendations are different is because of start up temperatures or do you disagree with that too?
Also, there is no means for regulating oil temperature on these. The colder the environment, the colder the engine oil.

Not at all, that’s why 10-30 is recommended for climates that don’t get below 0*. My questioning is when you go to 15-40. That changes the viscosity by quite a bit after it gets to operating temp as well as not filling the lifters as fast at start up. The oil temp after the engine is warmed up is regulated by the cooling system.

Update: Oil analysis shows lead (15) from bearings and sodium(161) and potassium(47) from coolant. I have not been loosing any noticeable amount of coolant. I do have a lifter tap on cold start that gets louder when I raise the idle (at least I think it's a lifter tap) and get a 'low oil pressure' light when stopping to back into my driveway from the hill.
So my theory is that bottom end bearings are worn from coolant, lifters worn from age, etc, possibly an oil pickup tube O ring issue and an intake gasket leak resulting in cold engine stumble and a slight crack in the head or head gasket (not surprising given it's history of neglect)

Blackstone labs recommended increasing my oil change interval to 2k miles to reduce coolant accumulation.
I will try 10w30 dino oil and add some Lucas oil. If the bottom end is the issue, this should quiet that, if the lifters are an issue, this will exasperate that. No good solutions IMO, I think the engine is about done.

Possibly you have less problem than you fear. The coolant could be a head gasket or cracked head. Have you looked into the possibility of Castech heads? There’s a good possibility of a bad oil pickup tube o-ring as well. But don’t write off the engine, these are hard to kill unless it’s sludge. Have you inspected the inside of the oil filters when you change them, and looked inside the valve covers for signs of sludge?

 

[iamdub]

Update: Oil analysis shows lead (15) from bearings and sodium(161) and potassium(47) from coolant. I have not been loosing any noticeable amount of coolant. I do have a lifter tap on cold start that gets louder when I raise the idle (at least I think it's a lifter tap) and get a 'low oil pressure' light when stopping to back into my driveway from the hill.
So my theory is that bottom end bearings are worn from coolant, lifters worn from age, etc, possibly an oil pickup tube O ring issue and an intake gasket leak resulting in cold engine stumble and a slight crack in the head or head gasket (not surprising given it's history of neglect)

Blackstone labs recommended increasing my oil change interval to 2k miles to reduce coolant accumulation.
I will try 10w30 dino oil and add some Lucas oil. If the bottom end is the issue, this should quiet that, if the lifters are an issue, this will exasperate that. No good solutions IMO, I think the engine is about done.

Have you popped off a rocker (valve) cover to check the inside for sludge?

 

[Larryjb]

Had you let oil change intervals go for much longer than recommended?

Was the oil sludgy when changing?

How many miles are on your motor?

I have about 200000 miles on my 5.3. I did have a cracked head that allowed a slow coolant leak into the oil. By the time I had to change my oil, it was sludgy and would come out in glops near the end. My oil pressure would start dropping about 1/2 way through a normal oil change interval. When I had my oil analysis done, all I had was evidence of coolant in the oil, so even with the coolant that was going into the oil, the analysis did not indicate any bearing wear beyond normal.

If you are not losing any noticeable coolant, and yet Blackstone sees evidence of coolant in your oil, a couple of things come to mind:
1) Are you losing coolant but it doesn't show in the coolant reservoir? This used to happen on the Chevy 3.8's when the radiator mounted cap would allow air to be sucked in instead of pulling the coolant in from the coolant reservoir. I'm going to say that is is possible on the Chevy 5.3, but perhaps unlikely because the 5.3 does not have a radiator mounted cap.
2) If your oil is not sludgy or chocolaty coloured, I'm going to go on a limb that the bearing damage was not caused by a coolant leak. However, you do say the engine suffers from years of neglect so that a previous coolant leak may have been possible that caused the damage to the bearings.
3) From your description, as long as the oil wasn't obviously sludgy, it sounds like you had a problem with oil flow that may have caused the bearing damage.

I have no idea how long an engine can continue to run with bearing wear, or if using a different oil can keep it running longer.

 

[OneofFew]

Have you popped off a rocker (valve) cover to check the inside for sludge?

I did pop one side off. I did not see anything disturbing.

 

[iamdub]

I did pop one side off. I did not see anything disturbing.

Then it may just be wear from the previous owner's neglect. The coolant in the report could be a recent event. Either way, it's gonna need to be opened up and, considering the history and current status, it's probably not worth it.

 

[OneofFew]

Had you let oil change intervals go for much longer than recommended?

Was the oil sludgy when changing?

How many miles are on your motor?

I have about 200000 miles on my 5.3. I did have a cracked head that allowed a slow coolant leak into the oil. By the time I had to change my oil, it was sludgy and would come out in glops near the end. My oil pressure would start dropping about 1/2 way through a normal oil change interval. When I had my oil analysis done, all I had was evidence of coolant in the oil, so even with the coolant that was going into the oil, the analysis did not indicate any bearing wear beyond normal.

If you are not losing any noticeable coolant, and yet Blackstone sees evidence of coolant in your oil, a couple of things come to mind:
1) Are you losing coolant but it doesn't show in the coolant reservoir? This used to happen on the Chevy 3.8's when the radiator mounted cap would allow air to be sucked in instead of pulling the coolant in from the coolant reservoir. I'm going to say that is is possible on the Chevy 5.3, but perhaps unlikely because the 5.3 does not have a radiator mounted cap.
2) If your oil is not sludgy or chocolaty coloured, I'm going to go on a limb that the bearing damage was not caused by a coolant leak. However, you do say the engine suffers from years of neglect so that a previous coolant leak may have been possible that caused the damage to the bearings.
3) From your description, as long as the oil wasn't obviously sludgy, it sounds like you had a problem with oil flow that may have caused the bearing damage.

I have no idea how long an engine can continue to run with bearing wear, or if using a different oil can keep it running longer.

I appreciate your input! Mine does not seem to be as bad as yours was. Current mileage is 266k. I will check for air in the cooling system.
I have been generally changing the oil every 5k with 10w30 or 5w30 synthetic. I do keep an eye on the condition of the oil up to the 5k interval. The oil analysis still shows good vicosity, no fuel or water dilution and I think the 5k interval is ok If it wasn't for the coolant. I do not think this engine has seen good service discipline late in its previous life, but I may be assuming. It sat for a while when I bought it and the oil was definitely old and nasty- but I never saw any sludge.
What I will do next (soon) oil change is dump a quart in with the drain plug out to try and wash any nasties out of the sump that may be getting into the oil pickup screen.

 

[OneofFew]

Not at all, that’s why 10-30 is recommended for climates that don’t get below 0*. My questioning is when you go to 15-40. That changes the viscosity by quite a bit after it gets to operating temp as well as not filling the lifters as fast at start up. The oil temp after the engine is warmed up is regulated by the cooling system.



Possibly you have less problem than you fear. The coolant could be a head gasket or cracked head. Have you looked into the possibility of Castech heads? There’s a good possibility of a bad oil pickup tube o-ring as well. But don’t write off the engine, these are hard to kill unless it’s sludge. Have you inspected the inside of the oil filters when you change them, and looked inside the valve covers for signs of sludge?

I do not have the notorious 704 (?) castechs. I think it is 864's that I have. As minor as the coolant leak is given the overheating history (was missing the thermostat, had a clogged radiator and green coolant when I bought it and I had to tow it home), I would think if I had castechs, id be pulling them right now. As it stands, I see no need to go through all that.

 

[Rocket Man]

I do not have the notorious 704 (?) castechs. I think it is 864's that I have. As minor as the coolant leak is given the overheating history (was missing the thermostat, had a clogged radiator and green coolant when I bought it and I had to tow it home), I would think if I had castechs, id be pulling them right now. As it stands, I see no need to go through all that.

Heads with either 706 or 862 with the Castech logo are problematic and the only way to tell for sure is to pull the rocker and look for the logo and casting number. More 706’s have problems but 862’s have a high failure rate too from what I’ve read. The cracks can be minor. Here’s a link to the TSB in case you haven’t read it. http://ww2.justanswer.com/uploads/Bluegorilla/2008-12-05_142924_Coolant_loss_5.3.pdf

 

[FrankU]

I'd use these as recommended by GM :

Genuine GM Fluid 12378255 Cooling System tabs.

 

[OneofFew]

Thank you all so much. I did when I initially came to this forum and read of the Castechs check and I am pretty certain I ruled out that I have the effected ones. Will look closer again.
I will try the tabs FrankU suggests and change the oil more frequently and retest the engine oil for changes.