2004 6.0 NV4500 Tahoe

[randeez]

nice rear end

 

[Dantheman1540]

If it still does it with the new oil, try priming it the next time. Hold the pedal to the floor (well, clutch and throttle in your case) and crank it for about 10 seconds. I don't know if the GMT800 PCM stops the cranking like it does on the GMT900. Let the starter cool for a bit, then repeat. Let off the throttle and crank as normal to see if there's any change.

That's a good idea I will have to try that. How would the pump start losing prime?

nice rear end

Thanks mate you can check it out at anytime

 

[iamdub]

That's a good idea I will have to try that. How would the pump start losing prime?



Thanks mate you can check it out at anytime

Really, for what I was describing, the whole oil system would have to drain down. That's the whole damned engine cuz the oil pump is at the bottom. The pump isn't air tight and neither is the engine. It doesn't really "suck" when it's dry. The rotors move volumes of liquid that are waaay thicker than air. Once the pump and the oil system are packed full of oil, it starts moving that oil as soon as the rotors are spinning. That moving oil is what does the sucking on the pickup tube. No moving oil in the pump = no flowing oil in the pickup tube = no flowing oil in the system. As far as what would cause it to drain as if you were cold starting engine that has been in hibernation without priming it- I don't know. Faulty ADBV in the filter, possibly coupled with some other factor(s), all exacerbated by the oil thickening in the cold? I may be going way off in left field. It's just that I don't believe that 30 degrees is all that cold for oil to act like this. I could be wrong, but I had to voice my concern, if only just to heighten your anxiety.

 

[iamdub]

After seeing @iamdub replace his evap canister a few weeks ago I thought "damn I hope I don't have to do that I hate those OEM fuel line connectors." Well about that time I noticed the pump handle would click off on it's own after just a few gallons. It got progressively worse over the last couple weeks to the point I had to hold it half way the entire time. I fill up 2-3 times a week and that was getting irritating fast.

So after doing the oil change I figured I might as well start off 2021 with a punishing task. There is just no room where the canister is with the 14b and being low. Ended up hitting my head really ******* the spare tire dangly thingy so it got cut out, same with some random bracket just sitting there not doing a damn thing.

Actually replaced the canister and valve pretty quick and easy but then decided to tackle a problem I've had since doing the 1410 yoke on the 14b. The yoke hits the evap bracket unless I run massive bump stops to kill all up travel and make for a harsh rear ride. I made it better than it originally was with some big rubber bumps but I still bumped out pretty often and my GF disliked it. So I realized the bracket it actually bolted to another bracket that spaces the whole thing probably 2-4" from the crossmember that runs almost even with the floor. Hacked that junk out and bolted it directly to that cross member freeing up a lot of space. Cut about an Inch off the bumps and its definitely better but there's a good bump down my local Mexico mile that it will still bottom out on so further hackery may be required.

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I don't have a 14 bolt, but my pumpkin might be getting too close for comfort. I'll have to look more closely, especially if I lower it more.

Did you check the purge circuit line for pellets? If you find some, DO NOT BLAST IT WITH COMPRESSED AIR. Use very gentle puffs, like about what you could do if you were blowing on it with that pretty mouth of yours, to coax the pellets out the lines. Hit it from both ends. If you try to blast them out with air, they'll wedge against each other and form a blockage. They're very light, which is how they can travel so far up the system. But they're also brittle, so, under pressure and speed inside a small pipe, they can collide and chip against each other to form facets and edges, essentially making them wedges.

 

[Dantheman1540]

Really, for what I was describing, the whole oil system would have to drain down. That's the whole damned engine cuz the oil pump is at the bottom. The pump isn't air tight and neither is the engine. It doesn't really "suck" when it's dry. The rotors move volumes of liquid that are waaay thicker than air. Once the pump and the oil system are packed full of oil, it starts moving that oil as soon as the rotors are spinning. That moving oil is what does the sucking on the pickup tube. No moving oil in the pump = no flowing oil in the pickup tube = no flowing oil in the system. As far as what would cause it to drain as if you were cold starting engine that has been in hibernation without priming it- I don't know. Faulty ADBV in the filter, possibly coupled with some other factor(s), all exacerbated by the oil thickening in the cold? I may be going way off in left field. It's just that I don't believe that 30 degrees is all that cold for oil to act like this. I could be wrong, but I had to voice my concern, if only just to heighten your anxiety.

I love all the theories that's why I'm on TYF. Luckily it's been a nice 75* all weekend so I haven't gotten to cold start it which is annoying because I need super cold start data for my VE table still. But that theory does make sense let's just hope it was a fluke

 

[Dantheman1540]

I don't have a 14 bolt, but my pumpkin might be getting too close for comfort. I'll have to look more closely, especially if I lower it more.

Did you check the purge circuit line for pellets? If you find some, DO NOT BLAST IT WITH COMPRESSED AIR. Use very gentle puffs, like about what you could do if you were blowing on it with that pretty mouth of yours, to coax the pellets out the lines. Hit it from both ends. If you try to blast them out with air, they'll wedge against each other and form a blockage. They're very light, which is how they can travel so far up the system. But they're also brittle, so, under pressure and speed inside a small pipe, they can collide and chip against each other to form facets and edges, essentially making them wedges.

I think I may have fixed the pinion problem, I need to cut some more off the bumps but I raced my 408 denali buddy a couple runs tonight with hard 1st gear launches and it still doesn't hit. Also doesn't stand a chance against the denali, it's so depressing I refuse to video it .


I jiggled the line but that's about it I honestly totally forgot about you saying there were pellets all through it. I did however fill 19gallons today and it didn't click once! . I guess if I get the "tighten fuel cap" message I'll know I should have checked the line.

 

[iamdub]

I jiggled the line but that's about it I honestly totally forgot about you saying there were pellets all through it..

Yup. All the way to the purge solenoid at the manifold:

I just wish I had known from the start to NOT hit it with 150 psi. That's why I dropped the tank- to bend and beat each line on the ground as I blew into them to break up the blockages. The pellets were packed near the bends in the lines since they have a slight crimp in the bends. I wasn't gonna remove the one on the frame that goes from the tank to the manifold, so I just kept blowing it from each end and tapping it near the bends with a small hammer for about an hour before I finally worked everything loose and the line seemed to blow freely. I inspected the pellets afterward and figured, by how brittle and lightweight they were and how they chipped when squished together, them with high speed and pressure was a recipe for a blockage disaster.

I did however fill 19gallons today and it didn't click once! . I guess if I get the "tighten fuel cap" message I'll know I should have checked the line.

After dropping the tank and all that mess, this kind of WOT is the most satisfying!

 

[randeez]

damn that sucks all the way up there!
mine was doing the handle clicky thing pretty bad, swapped without blowing out any of the lines and havent had a problem since. i have had that purge solenoid off a few times and never noticed anything there

 

[iamdub]

damn that sucks all the way up there!
mine was doing the handle clicky thing pretty bad, swapped without blowing out any of the lines and havent had a problem since. i have had that purge solenoid off a few times and never noticed anything there

I took my solenoid off and blew on it while hitting it with 12v. Nothing came out so I comforted myself with the assumption that it acted as a filter and kept the rat turds out of the engine.

I wanted to do it all once and be done, so I was extra thorough. I botched something with the fuel pump bucket so I have to do it all again anyway.

 

[Dantheman1540]

I'm gonna hope that evap systems in florida don't send the little back balls down the tubes so I'll get lucky like Randy.