George B
¯\_(ツ)_/¯
Probably the one I have to change...
What did you do to your NNBS GMT900 Tahoe/Yukon Today?
- Thread starter phattyford
- Start date
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pwtr02ss
Full Access Member
Denso. My AcDelco OEM units had "denso" stamped right on them.
pwtr02ss
Full Access Member
Its the B1S2 thats a bastard. The driver side is easy. Then sensor comes with a new push pin clip so don't waste 30 minutes trying not to break the stock one like I did, only to open the damn box and see it had a brand new one already installed...
Just reach above the trans and pull down. Theres enough wire length to get it unplugged. The socket will help, along with some lube
Just Fishing
Can't fix stupid
This last time i did, and i got the alignment of the belt pretty good.
Hard part is that the pully has nothing to bottom out on.
I went with the arp balancer bolt this time, and it makes alignment even harder.
No real difference between a brand new balancer and the old one either.
I might end up going back to the oem bolt, that one seems to have some built in sealant that might prevent the balancer from spinning?
Super weird design imo.
I have done 2 with the ARP bolt, never had an issue.
Do I remember you doing something to the oil passages in the top end or was that something or someone else? My memory isn’t what it used to be. Im just wondering out loud here, thinking if you did that it might be part of the problem if it’s causing oil starvation elsewhere.yeah i did just the thrust bearing and it burned it out again.
since then i also bypassed the trans oil coolers after attempting to get a before and after pressure reading.
Was never able to confirm for sure due to a short oil pressure gauge hose, but i did notice i'm getting more transmission/engine breaking with the coolers bypassed.
I also was able to reverse flush some metal from the transmission cooler when i disconnected it, so i'm feeling pretty good that it's the issue...
I left it there, decided i was done and needed to get outside and do things for the remaining part of the summer.
getting back to it now, plan is to pull the pan and see if the crank looks ok, or if i see more damage than last time.
Plan is to roll a new (probably the original used 5.3 thrust i have) thrust bearing in to place to see if it burns it out.
If it looks good, then i'll roll a fresh bearing into place and run it.
If the engine gets pulled, i'm installing a transmission pressure gauge (probably a perm install like i did to my vette).
Transmission pump will probably get replaced for good measure.
and all new bearings, and possibly new crank.
I'm hoping i don't need to go that far.
Just Fishing
Can't fix stupid
I did some oil passageway matching and flowing in the block.
Matched the pan to the block as well.
This last attempt, i also added some oil flow passages to the thrust bearing surface
that was per the instructions from the manufacture of my mains (mahle iirc)
I also have the high-pressure high-volume Melling oil pump (low pressure spring installed).
if anything, it has too much oil flow/volume.
One thing to note, oil pressure is nice and above 40psi at hot idle with a fresh main.
when the thrust surface starts to get worn, i notice the hot oil pressure starts to dip under 40psi.
but i can nearly pin the pressure gauge over 4krpm.
And even with the updated valve cover, and the 3/4in valve cover spacers.
I still get some oil in the catch can.
but only when the oil pressure spikes during a run.
Leading me to think i'm either flooding the heads with oil, or more likely it's spraying up and making it into the pcv.
Also noting that the high flow pump warning was included in the cylinder head manufacture instructions (AFR).
They mentioned that it's possible to flood the valve seals unless the heads were flowed for oil return.
No information on how to do that, however comparing the stock 799 heads they looked like the oil return was a tad better.
And on that, i did modify the lifter trays to help with the oil return, I didn't go crazy as i wanted to keep some oil in the trays.
but they have a path to balance oil between the lifters, and a quicker return path pointed in the center of the block.
In theory, it looked like a good idea.
If the engine comes apart again, i'm going to dump the high flow pump.
And probably go back to an unmodified tray setup.
I do recall that my oil pressure started going weird during engine break-in when trying to do an engine breaking cycle down a hill.
rpm went a little too high, but i ran with it until i saw the oil pressure fluctuate a little.
My issues probably started right around that time, i also had my engine breaking cut to near nothing right about then as well.
blaming that for the trans cooler passageways since engine breaking seems to have returned...
I haven't looked at flow paths in the 6l80, but it's a thing in the 4l60's.
Mostly it's that trans fluid gets cut off to the rear clutches or something along those lines.
I sorta want to pull the engine apart, it would be nice to see how it's doing...
I did get a good look at the cylinder bores from the underside view, and it looks fantastic.
Nice oiling, all cylinders look good.
I also have a spare set of head gaskets on hand.
I ran with a .037 quench instead of the safer ".040".
On one hand,
If it comes apart, i can lower the compression a little more.
(it's like 10.32 right now)
on the other hand, the engine runs great as is, throttle response is quick even with a cobbled together tune.
No real noticeable pinging, even with that low octane fuel i had in the tank.
Probably because of the tight quench...
So, if the engine comes apart, i'll loosen the quench, and lower the compression slightly with that...
Per my lil calculator, it drops it to 10.25 with the different gasket.
I don't really want to change the current setup, just make it work.
Low-end is fantastic, it's the perfect cruiser.
I also ran the 6.2 timing table for a quick run before the issues started, it's "OMG" good.
I'm worried if i lower the compression and loosen up the quench, i might lose some of that awesome low-end power i got.
(Sorry you got morning Chris thoughts/rambling
)Also, for anyone that builds engines might know if this is a problem
My crank has what i felt was a rough crank polish.
it's probably like 400-600 grit.
Then i used "race" bearings (tri metal).
the coating pretty much completely came off of the bearings.
still has the soft surface underneath.
I don't see any real thickness change, so i don't think it's an issue.
Just looking at my oem bearings, the coating is still there.
The crank seemed to also polish with the oem bearings.
My crank surface has no change...
I'm wondering if i needed a high polish on the crank for those race bearings.
Or am i just overthinking things?
Just Fishing
Can't fix stupid
Also if i pull the engine apart again, I'm thinking i want to run something through the oil passageway for the main bearing.
Maybe do some very light "flowing"
but then i'm looking at a detailed block cleaning, and this will be in the winter...
I did pull the rod bearing that shared the oil passageway with the thrust, compared to several others.
it looked pretty uniform with the wear.
Maybe do some very light "flowing"
but then i'm looking at a detailed block cleaning, and this will be in the winter...
I did pull the rod bearing that shared the oil passageway with the thrust, compared to several others.
it looked pretty uniform with the wear.
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iamdub
Full Access Member
Could that super-duper-mega-pressure-and-volume pump be sucking the sump dry, causing momentary loss of pressure that somehow affects that thrust bearing? Off the top of my head, this doesn't make sense since the lifters and all above get and lose pressure first. Still grasping at straws here.
...On one hand,
If it comes apart, i can lower the compression a little more.
(it's like 10.32 right now)
on the other hand, the engine runs great as is, throttle response is quick even with a cobbled together tune.
No real noticeable pinging, even with that low octane fuel i had in the tank.
Probably because of the tight quench...
So, if the engine comes apart, i'll loosen the quench, and lower the compression slightly with that...
Per my lil calculator, it drops it to 10.25 with the different gasket.
I don't really want to change the current setup, just make it work.
Low-end is fantastic, it's the perfect cruiser.
I also ran the 6.2 timing table for a quick run before the issues started, it's "OMG" good.
I'm worried if i lower the compression and loosen up the quench, i might lose some of that awesome low-end power i got.
(Sorry you got morning Chris thoughts/rambling
What would be the benefit of lowering the CR and loosening the quench? Maybe a slightly larger window for a degree or three of timing at most. There's just no difference in that .003" extra piston space or 7 tenths of a point of compression to bother pulling the heads. Unless you have it apart for something else and those are the gaskets you have on hand. If those are your true CR numbers, you wouldn't even notice the difference.
It certainly has no relation to your thrust bearing woes.
Kee Fuller
Full Access Member
Y’all remember the airbag issue/seat position sensor I’ve been trying to figure out for the past month? Well i finally gave in and took it to the dealership. So apparently somewhere in the harness there’s a shortage. Go figure.
On another note. When i get my truck back I’m going to install this rear view mirror with camera myself. The rear camera is going where the oem camera is going under the tailgate. Should i just drill the camera directly or there or make so kind of plate to put the camera on, then mount under the tailgate.
On another note. When i get my truck back I’m going to install this rear view mirror with camera myself. The rear camera is going where the oem camera is going under the tailgate. Should i just drill the camera directly or there or make so kind of plate to put the camera on, then mount under the tailgate.
