Look at this. Scary

[99xcss4]

okay got ya thanks

 

[GoToGuy]

You know if you have the OE service manual available here in the forum to download. In the first chapter has the service schedule, basic descriptions, it does, not dose, list all the RPO codes for that year truck, or Sub/ Tahoe. Some codes are used to describe what the option is, but will vary by model and year. Example: G80 = locking differential/ limited slip differential/ posictrac differential. Most are very accurate.
If you have the service manual, you will always have the correct RPO definitions, the options are all in the two books. Service and Repair.

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wgats listed is what was available for your year

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[Boots97]

That's a symptom of a weak belt tensioner. It's been 15 years so memory is not perfect; had a Cummins that kept eating belts, even with new tensioners. Cummins engineers said only to use Cummins tensioners, or to check the torque required to deflect the tensioner from the belt; 30 lbs-ft was the number I recall, with the wrench 90* from the tensioner leg. The non-cummins tensioners all tested below 20 lbs-ft. I put a new belt on the 6.5TD truck a couple thou ago when I bought it, but not a new tensioner; when the engine is running especially with A/C engaged the tensioner bounces. Notably, sometimes the new A/C compressor, with paint still on the pulley, slips and squeals at startup. So quite obviously the tensioner is inadequate.
Edit; the Cummins was a N14, not a pickup truck engine so the belt was probably 50% wider. I haven't measured torque on these pickup motors, but maybe I'll go do that now.
/

I agree. Even if the tensioner seems fine, I'd replace it anyways knowing how bad that belt is.

Whenever I buy a "new" car, there's a handful of parts I almost always buy.

1. Spark Plugs

2. Spark Plug Wires

3. New Silicone Windshield Wipers

4. New Serpentine Belt

5. New Battery (depends on the date)

6. Clearcoat for my Headlights/Taillights

7. Sandpaper if I need it

8. Tires (depending on the wear)

 

[k1500 97]

FYI, this is basically the "GM Master RPO List" that's been circulating for years with a search function built into it. Which is to say, not really the best choice for accurate information. For instance if you type in "G80" you get "AXLE,REAR,POSITRACTION,LIMITED SLIP" which is correct for something like an F-body Camaro/Firebird, but not for these trucks which got lockers. GM recycled many (most) of the RPO codes over the years with different vehicles so what's accurate for one vehicle may not be for another. This is why I recommend compnine.com for RPO look-ups. It costs money, but in my experience their RPO descriptions are pretty much always accurate to the specific vehicle in question.

@1ton-o-fun has an account with CompNine and has offered to run VINs for members here for free, but he hasn't been on here in a couple months.

https://www.gmt400.com/threads/vin-decoder.51712/

Thank you.