Mysterious oil level and burn issue

[lowpost99]

My 00' NBS Tahoe was about 4 hrs into a 8hr road trip two weeks ago when I noticed the infamous lifter tick sound, and my pressure dipped from about 35-40psi to about 20psi. I stopped and checked the oil, and it showed that I was about 3 quarts low. I added a quart and continued on my way home, the lifter tick subsided and I checked the oil the next day, it showed about a quart overfilled.
Now for some additional background, about 20 months ago, I solved the infamous lifter tick sound at startup issue by pulling the cam covers off and cleaning the rockers arms and the push rods portholes at the bottom of them. All went well and the truck drove like a charm.

So I've been driving about for about two weeks since that road trip, and I found that the oil filer tube was installed poorly and oil was likely leaking from there as I saw a lot of buildup, so I removed the cam covers again to remove it and I found this mucus thick, black sludge coating the covers about an 1/8 in thick. I cleaned the cam covers with degreaser and scrubbed them clean. Then I discover that the rocker arm screws and the push rods are really locked in from burnt oil build up. I mean I've been spraying with brake cleaner and liquid wrench for 3 days and they are still really stuck in there. I got a few of the rockers off, but none of push rods want to come out. When I did it before they slid out very easily.

My question is before I break something trying to pry it loose, should I put the covers back on and run some kerosene or other motor flush chemical in the oil for about 15-20 mins and then come back to cleaning those parts after I drain the oil and whatever sludge it drags out? I'm afraid that even if I safely get them all out, they'll just clog up again when I crank the car up to warm the oil for an oil change

 

[swathdiver]

My 00' NBS Tahoe was about 4 hrs into a 8hr road trip two weeks ago when I noticed the infamous lifter tick sound, and my pressure dipped from about 35-40psi to about 20psi. I stopped and checked the oil, and it showed that I was about 3 quarts low. I added a quart and continued on my way home, the lifter tick subsided and I checked the oil the next day, it showed about a quart overfilled.
Now for some additional background, about 20 months ago, I solved the infamous lifter tick sound at startup issue by pulling the cam covers off and cleaning the rockers arms and the push rods portholes at the bottom of them. All went well and the truck drove like a charm.

So I've been driving about for about two weeks since that road trip, and I found that the oil filer tube was installed poorly and oil was likely leaking from there as I saw a lot of buildup, so I removed the cam covers again to remove it and I found this mucus thick, black sludge coating the covers about an 1/8 in thick. I cleaned the cam covers with degreaser and scrubbed them clean. Then I discover that the rocker arm screws and the push rods are really locked in from burnt oil build up. I mean I've been spraying with brake cleaner and liquid wrench for 3 days and they are still really stuck in there. I got a few of the rockers off, but none of push rods want to come out. When I did it before they slid out very easily.

My question is before I break something trying to pry it loose, should I put the covers back on and run some kerosene or other motor flush chemical in the oil for about 15-20 mins and then come back to cleaning those parts after I drain the oil and whatever sludge it drags out? I'm afraid that even if I safely get them all out, they'll just clog up again when I crank the car up to warm the oil for an oil change

Do you have any photos of the sludge Morgan? I'm wondering if coolant got mixed in there...

 

[lowpost99]

No I didn't take any photos before cleaning. I could drain some oil from the pan for a photo if you think that would help my post, put the nut back in to save enough in to aid in the flush. BTW, I was using a synthetic blend of oil if that makes any difference.

 

[BG1988]

My 00' NBS Tahoe was about 4 hrs into a 8hr road trip two weeks ago when I noticed the infamous lifter tick sound, and my pressure dipped from about 35-40psi to about 20psi. I stopped and checked the oil, and it showed that I was about 3 quarts low. I added a quart and continued on my way home, the lifter tick subsided and I checked the oil the next day, it showed about a quart overfilled.
Now for some additional background, about 20 months ago, I solved the infamous lifter tick sound at startup issue by pulling the cam covers off and cleaning the rockers arms and the push rods portholes at the bottom of them. All went well and the truck drove like a charm.

So I've been driving about for about two weeks since that road trip, and I found that the oil filer tube was installed poorly and oil was likely leaking from there as I saw a lot of buildup, so I removed the cam covers again to remove it and I found this mucus thick, black sludge coating the covers about an 1/8 in thick. I cleaned the cam covers with degreaser and scrubbed them clean. Then I discover that the rocker arm screws and the push rods are really locked in from burnt oil build up. I mean I've been spraying with brake cleaner and liquid wrench for 3 days and they are still really stuck in there. I got a few of the rockers off, but none of push rods want to come out. When I did it before they slid out very easily.

My question is before I break something trying to pry it loose, should I put the covers back on and run some kerosene or other motor flush chemical in the oil for about 15-20 mins and then come back to cleaning those parts after I drain the oil and whatever sludge it drags out? I'm afraid that even if I safely get them all out, they'll just clog up again when I crank the car up to warm the oil for an oil change

but you can get 300 hectors to a single tank of Kerosene



that is what happens when you change the oil every 7-10,000 miles on conventional oil


with conventional oil it needs replacement at 3,000 and synthetic at 4,000 miles.. I know I bought a tahoe with a sneaky clean engine.. I wish they had the tall boy oil filters this way i could change it at 7,000 miles it would save me $$$$ like 57$ each time

 

[swathdiver]

No I didn't take any photos before cleaning. I could drain some oil from the pan for a photo if you think that would help my post, put the nut back in to save enough in to aid in the flush. BTW, I was using a synthetic blend of oil if that makes any difference.

What often happens is that the original owner did not change the oil as often as they should have and many used conventional oil, not even blended. Even following the 7500 interval with conventional oil is going to allow crud to build up inside the engine. Introducing a blend and especially full synthetic oil begins to break down the crud and sludge which in turn causes all kinds of problems with the AFM system and even the oiling system if it is really bad.

 

[lowpost99]

I have changed the oil religiously every 3-4k mi, and I did a flush and pan drop, clean and oil pump replacement with new o-ring about 3 years ago, about a 1 year ago, I changed out my Y-pipe and catalytic converters, and oxygen sensors. Strangely, the instructions came with some notice about our GM engines burning a quart of oil like every 30 days, and ever since then, I began to notice a loss of oil at the dipstick, and then unusually low oil levels like none on the stick, and then add some and days later, appearing overfilled. I wonder if the oil pump screen is clogged or the o-ring is bad again. I also recall there being some question as to whether the correct o-ring part should have been the red or green one. Maybe it's time to drop the pan again and pull the pickup tube, o-ring and screen. Does anyone have the correct part #'s for the screen and the correct o-ring handy?