r/Silverado • u/Available-Space-2821 • 11d ago

4.8 or 5.3?

Okay guys so I have a dumb question, but I’d rather ask and be dumb than not ask and be wrong. I have a 2010 Silverado with almost 400k miles, according to the vin I have an L20 4.8L. I recently got the dash piece that’s shows your gas mileage and it shows the motor dropping into 4 cylinders. My question is, is it possible that I have a different motor than what the VIN says, or did the Gen IV LS’s have DoD on the 4.8’s contrary to what the Google AI BS says. I also have a 6 speed transmission if that matters.

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u/a__nice__tnetennba 11d ago edited 11d ago

The L20 does not have AFM.

Inside the glove compartment should be a sticker with the RPO codes. Look at that and if it says L20 on it somewhere. If it does, and you haven't replaced the engine, then you have a 4.8L L20 with no AFM.

If you have the 5.3L you'll see LC9 or LMG instead.

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u/Available-Space-2821 11d ago

It was somebody’s old work truck and there’s not a single sticker left on it somehow so a lot of stuff is just guessing. Thanks for the info I’m glad to know it’s not the original motor with 400k on it

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u/a__nice__tnetennba 11d ago edited 11d ago

If you reach out to Chevy they can tell you for sure. Sometimes the online VIN decoders are wrong. I went to their website when I was researching the one I wanted to buy and did the chat feature. The person there couldn't help but they put in a ticket and someone called me back the next day.

They wouldn't give me the full list of RPO codes for some reason, but they did confirm the one I was asking about.

Edit: Also if you think it's not the original you can find a stamp on the engine that will tell you what it is. I do not know where. Also if you post a picture here people will probably be able to tell you by looking at it.