What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[George B]

I replaced the sensor and the screen the first time. The screen clogged up a second time and I didn't put it back in. I had DOD shut off in the tune though. I'm not sure why its there but I'm betting there's a million of them on the road without one.

To me that’s indicative of a sludge problem in the engine when a screen in the pressurized oil gallery is clogging. The more I read about failures in these engines my opinion continues to shift toward dirty oil being the root cause, not DOD per se. I suspec GM set the oil change intervals too long. Of course if there’s a failure beyond the warranty, and they sell a new car, is that really a failure? Or planned obsolescence.

I remember reading somewhere that the screen is meant to protect the sensor from that debris in the oil because it gets into the orifice of the sender and causes it to fail. Nit sure how true that is. I agree that the long OCI could very well be an issue.

 

[pwtr02ss]

To me that’s indicative of a sludge problem in the engine when a screen in the pressurized oil gallery is clogging. The more I read about failures in these engines my opinion continues to shift toward dirty oil being the root cause, not DOD per se. I suspect GM set the oil change intervals too long. Of course if there’s a failure beyond the warranty, and they sell a new car, is that really a failure? Or planned obsolescence.

I remember reading somewhere that the screen is meant to protect the sensor from that debris in the oil because it gets into the orifice of the sender and causes it to fail. Nit sure how true that is. I agree that the long OCI could very well be an issue.

I agree 100%. Mine was sludge from adding additional oil to diagnose an oil pump o-ring failure. I added 2 extra quarts and that broke loose build up from the oil level bing higher than it had for the previous 190k miles.

 

[Bill 1960]

I remember reading somewhere that the screen is meant to protect the sensor from that debris in the oil because it gets into the orifice of the sender and causes it to fail. Nit sure how true that is. I agree that the long OCI could very well be an issue.

Exactly. And if there’s debris that large in the oil gallery (after the filter! ) then what’s that doing to the bearings and lifters?

 

[avalonandl]

I short cycle my oil changes now. My Denali XL has 162k on it now and basically I plan on doing oil changes at 4-5,000 miles. My theory is the previous owners were more concerned about how the vehicle looked rather than maintained it. It had the OEM plugs in it, at 134k miles, had the Jax car wash sticker on it but very few oil changes on the Carfax. Now i know that many small OC places do not report maintenance so I am sure OC were performed. But I am religious about it now. Always was.

 

[Doubeleive]

I do mine old school @3k

 

[pwtr02ss]

I do 5k intervals with mobil 1 and wix filter.

 

[Bill 1960]

I short cycle my oil changes now. My Denali XL has 162k on it now and basically I plan on doing oil changes at 4-5,000 miles. My theory is the previous owners were more concerned about how the vehicle looked rather than maintained it. It had the OEM plugs in it, at 134k miles, had the Jax car wash sticker on it but very few oil changes on the Carfax. Now i know that many small OC places do not report maintenance so I am sure OC were performed. But I am religious about it now. Always was.

Ditto. I am changing mine on about a 2k interval at present, and it’s coming out dark. I got this vehicle at 60k (but 10k hours so lots of slow speeds or idling) and and I’ve done changes at 60, 62, and 64. If it reaches the point where a 2k drain comes out amber then I’ll start extending it.

My belief is factory OCI will build deposits as contamination exceeds the carrying capacity of the oil in the latter part of the cycle. Short OCI especially with good detergent oils will reverse that.

 

[gooffeyguy]

So I'm in the process of changing the sensor out. I can get to it OK, but I can't get the connector off. The side with the safety clip that pulls up and the push retainer is almost facing forward, a bit angled, towards the drivers headlight. It's really hard to get my fat thumbs between it and that damn plastic tower/shield mounted to back of engine. What the hell is that for anyway?

 

[gooffeyguy]

They need to make the socket with a notch up the side like the O2 sensor sockets so I could at least turn it a bit so I can get to the clips

 

[Tonyrodz]

So I'm in the process of changing the sensor out. I can get to it OK, but I can't get the connector off. The side with the safety clip that pulls up and the push retainer is almost facing forward, a bit angled, towards the drivers headlight. It's really hard to get my fat thumbs between it and that damn plastic tower/shield mounted to back of engine. What the hell is that for anyway?

How about using a pick?