What did you do to your NBS GMT800 Tahoe/Yukon Today?

[ScottyBoy]

It's possible that all that sludge was already there in 2017, and it finally broke loose and fell into the oil pan with new oil and consistent oil change intervals.

Are you using high mileage oil? My understanding is the HM oil will contain detergents that will break up sludge and cause it to fall into the oil pan. If the PO only ever used conventional oil, and had extended oil change intervals, it could have caused the buildup you're seeing.

When did you purchase the truck, and how many miles have you put on it since you bought it? How many miles are on it now?

I purchased the truck in 2005 with 51k miles on it. Since then I have ALWAYS ran either Mobil1 full synthetic, or Amsoil XL series synthetic. No high mileage formulations. Longest I've ever gone was 7500 miles on an oil change, but when I saw how bad the oil looked I stopped doing that and changed it about every 5k miles ever since. It currently has 160k miles on it. I don't put a lot of miles on it, so a few times I've gone a year on the same oil because I didn't even put 5k miles on it. I wonder if sheer age of the oil is causing sludge?
Oh, and I've probably put about 40k miles on it since I last had this oil pan off in 2017. I also replaced the valve cover gaskets around the same time, and the top end of the engine appeared to be pretty clean.

 

[smcnair]

Got my oil pan dropped today and that sumbitch is FULL of sludge! Boy am I pissed. I COMPLETELY cleaned this pan out when I replaced the gasket and pickup tube in 2017. Since then I have changed the oil every 5,000 miles with Amsoil XL series oil and either a Mobil1 filter or a Wix XP filter. I'll admit though, the last 2 oil changes I used Mobil1 oil and then Walmart Supertech Full Synthetic for the last oil change. (about 3 months ago). In the bottom of the pan there is a THICK mud like sludge, and on the baffle, there is some hard caked up sludge that is flaking off in chunks kind of like rust. It also has a slight metallic color to it. Can anyone with more insight than me explain WTF is going on here?

It may be time...

BG Dynamic Engine Cleaner

As Step 1 of two, this potent cleaner thoroughly cleans the crankcase and the entire lubrication system.

www.bgprod.com

 

[Sam Harris]

Yours looks pretty level, did you just raise the torsion bars?

Yessir. Cranked keys, and upgraded to longer Bilstein 5100’s. She rides just great too. I thought I’d suffer a terrible ride after cranking the keys, but really can’t tell any difference.

 

[Sam Harris]

That Color has always been a favorite of mine. Damn good looking ride man. Whats the specs on the tire size???

Thanks man! It’s grown on me a lot..! Still think the Bermuda Blue is the best, but I definitely love this color as well. Tires are 285/60 18’s on 2015 Yukon wheels. Fit perfectly, no spacers, or trimming.

 

[Walchit]

I get my alignment on Nov 3rd I think. But it seemed to ride really nice after I got the rear sway bar back on. It was a little wobbly on the way out to the shop without it, lol. I got the 2" keys from RC too. I only got her up to about 60, but the rough country shocks seemed decent. I watched a video comparing the shorter Bilsteins with extenders, vs RC. And the guy liked the Bilsteins better. You could see that it was less bouncy with them then the rough country shocks. Maybe someday Bilsteins will make it on my to-do list.

Yessir. Cranked keys, and upgraded to longer Bilstein 5100’s. She rides just great too. I thought I’d suffer a terrible ride after cranking the keys, but really can’t tell any difference.

 

[Rocket Man]

I purchased the truck in 2005 with 51k miles on it. Since then I have ALWAYS ran either Mobil1 full synthetic, or Amsoil XL series synthetic. No high mileage formulations. Longest I've ever gone was 7500 miles on an oil change, but when I saw how bad the oil looked I stopped doing that and changed it about every 5k miles ever since. It currently has 160k miles on it. I don't put a lot of miles on it, so a few times I've gone a year on the same oil because I didn't even put 5k miles on it. I wonder if sheer age of the oil is causing sludge?
Oh, and I've probably put about 40k miles on it since I last had this oil pan off in 2017. I also replaced the valve cover gaskets around the same time, and the top end of the engine appeared to be pretty clean.

I change mine every 3k. M1 Synthetic, Wix filter. I have 175k on it and had the pan off at about 150k and no sludge present. I would at the very least up your oil OCI and probably should send in samples to Blackstone Labs for analysis on a regular basis. IMO 5k is way to far to go on oil especially if it had sludge prior.

 

[blueinkd]

Finally went to junk yard this weekend and got a replacement door sill. My old one had the weatherstripping hanging/ripped. They had several yukons/tahoes and I came across several sub boxes. I may go back for one next weekend.

 

[Tonyrodz]

Got my oil pan dropped today and that sumbitch is FULL of sludge! Boy am I pissed. I COMPLETELY cleaned this pan out when I replaced the gasket and pickup tube in 2017. Since then I have changed the oil every 5,000 miles with Amsoil XL series oil and either a Mobil1 filter or a Wix XP filter. I'll admit though, the last 2 oil changes I used Mobil1 oil and then Walmart Supertech Full Synthetic for the last oil change. (about 3 months ago). In the bottom of the pan there is a THICK mud like sludge, and on the baffle, there is some hard caked up sludge that is flaking off in chunks kind of like rust. It also has a slight metallic color to it. Can anyone with more insight than me explain WTF is going on here?

My Express van pan looked EXACTLY like yours. I bet it looks the same again.

 

[ScottyBoy]

It may be time...

BG Dynamic Engine Cleaner

As Step 1 of two, this potent cleaner thoroughly cleans the crankcase and the entire lubrication system.

www.bgprod.com

If anyone actually SOLD this stuff I would buy some. But the only places that do have BG products will not sell them. They will only perform service with BG products.

 

[ScottyBoy]

My Express van pan looked EXACTLY like yours. I bet it looks the same again.

Probably so, nothing would surprise me now after seeing this crap.
Here's what my pan looks like now after a few minutes of scrubbing it with some LA Awesome from Dollar Tree. That stuff is the ****. I'm not done with it though, I'm gonna give it at least one more scrub. I need to find my wire brush so I can get the spots in the corners that I missed.