Might be my worst nightmare.... low oil pressure, tick noise after 75+mph

[SnowDrifter]

Are we just like not going to address the coolant freezing? That can **** stuff up MAJOR. The fact that you're leaking coolant tells me it's busted something.

Have you sent in oil to a lab?

 

[OR VietVet]

First, what is a freeze line? Second, he said after "taking care of the antifreeze" he still saw some drops of antifreeze. At that point he needs to pressure test the cooling system but I would only guess that the coolant leak is a separate second issue. The mechanical noise and pressure loss is the main problem but yes, cannot lose focus on the other issue. Either way it looks like major work ahead. Depending on what he does he may fix both with one repair. The coolant freezing happened because he came from Texas with the rig that had low anti freeze protection from a warmer climate that was diluted with water from adding water because of the initial leak. Could even have coolant in the oil. If I was a major engine tech at a shop I would be salivating for this job right now.

 

[HiHoeSilver]

All good posts here.

Average oil pressure for your NBS truck is 40 at idle. They are not like nnbs that seem to be all over the place and force you to figure it out when they can't clear 10 psi. In my experience, if an NBS isn't idling at 40ish, something's wrong. Do an oil change, take a sample for the lab, and look for coolant.

Agree with @SnowDrifter, the truck freezing can be a BIG deal. Are you losing coolant measurably?

Side question: why didn't you change the knock sensors when you had the intake off?

 

[SnowDrifter]

FWIW, because reading the dash gauge can be a bit error prone, the oil pressure in a good engine should be 33-35 running a mid grade Xw30 at operating temp at a 530rpm idle (that means 30+ mins of driving), with low miles on the oil before any shearing / volatility loss has chance to change your viscosity.

Also, just going to say this now: Just because they're called freeze plugs by common nomenclature doesn't mean they do anything for freezing. Those plugs only exist to aid in casting and removal of casting sand and do NOT do anything in the event of a cooling system freeze.

I should also add that I'm not saying to ignore the pickup tube o-ring or oil pump issues as a source of diagnosis(It IS a common problem). Only that my first step before doing a mechanical teardown would be to get a lab test and evaluate. Doesn't make sense to start putting hours of labor and a few hundo in parts to the thing blindly given the history. The $20-30 bucks on a lab test here is well worth while.

 

[OR VietVet]

All good points but are you saying the freeze line is actually a freeze plug, that he was talking about? That opens up another can of worms if is leaking from a freeze plug, better known as a "welch plug" also known as a core plug. Signs of internal rust in the cooling system, caused by too much water from Texas-maybe, can also lead to internal gasket and seal failure that can contribute to other internal engine problems. Maybe even attacking the oil system thru gaskets and seals.

I guess them Texas boys/girls can be tough on engines.

 

[mikeyss]

This may be a long shot, but the ticking could be coming from a broken exhaust manifold bolt. I know this doesn't explain the oil pressure, but it's worth checking out.

 

[DenaliReyes]

Are we just like not going to address the coolant freezing? That can **** stuff up MAJOR. The fact that you're leaking coolant tells me it's busted something.

Have you sent in oil to a lab?

The Denali had an extension cord that keeps the radiator warm, some sort of heater like fish tanks lol. I found that out before I drove it here, whilst changing o2 sensors my dad pointed it out.
Once the cold started I would.keep.it plugged for about 6 hrs. Help quite alot.

Eventually I flushed it and changed to a more concentrated mix.

The freezing really effected the reservoir and the pumps more. Because of the water in it. Broke 2 pumps, rear and windshield ones.

I have kept an eye on the oil when I change it and it's all oil, no water, chocolate mix nothing like that.

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[DenaliReyes]

First, what is a freeze line? Second, he said after "taking care of the antifreeze" he still saw some drops of antifreeze. At that point he needs to pressure test the cooling system but I would only guess that the coolant leak is a separate second issue. The mechanical noise and pressure loss is the main problem but yes, cannot lose focus on the other issue. Either way it looks like major work ahead. Depending on what he does he may fix both with one repair. The coolant freezing happened because he came from Texas with the rig that had low anti freeze protection from a warmer climate that was diluted with water from adding water because of the initial leak. Could even have coolant in the oil. If I was a major engine tech at a shop I would be salivating for this job right now.

I dont know what to call it but it's the antifreeze line that is seen going over the side of the valley pan. On some models. I'll take a picture of it tomorrow, I think the prob there is the gasket is prolly done.

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View attachment 230727

 

[DenaliReyes]

All good posts here.

Average oil pressure for your NBS truck is 40 at idle. They are not like nnbs that seem to be all over the place and force you to figure it out when they can't clear 10 psi. In my experience, if an NBS isn't idling at 40ish, something's wrong. Do an oil change, take a sample for the lab, and look for coolant.

Agree with @SnowDrifter, the truck freezing can be a BIG deal. Are you losing coolant measurably?

Side question: why didn't you change the knock sensors when you had the intake off?

Not losing any drastic coolant, knock wood, see pics. The dirty one was mine, the bottom left circle, bypass coolant line os what I meant. I see a little bit of coolant leake from there at times. The left picture, clean one, shows a different model. Wonder if 6.0s should have that one.

Anyway, that's what i meant by freeze line, sorry for the confusion, I'm still learning the lingo on these parts as i work on them.

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[iamdub]

Coolant crossover tubes. Often called "steam vent tubes".