2007 Camry v6 engine knock

I have a 2007 Camry XLE with 30,000 miles on it purchased new.I stated it up the other day after setting all night it had a very loud knock in the engine I shut it off and had it towed to the dealership.They started it up and wanted to know what happened they said it sounded like a rod out.They keep it several days and ended up doing a top engine flush and then replaced the spark plugs.They said it was a carbon build up.I asked if they suggest any thing to keep this from happening and they said they do not recommend using any thing.I thought carbon deposits were supposed to be a thing of the past. Does this still happen. CandC

Do You Regularly Use “Top Tier Gasoline” ? For What It’s Worth, Toyota Is One Of The Manufacturer’s Recommending Its Use. Does It Help ? I Don’t Know, But I Usually Buy It.

I believe your Owner’s Manual has the recommendation, too.
If you’re not familiar with it, here’s a link:

http://www.toptiergas.com/

CSA

That is all that has ever been used???

We’ve never used top-tier gas on our 07 Lexus (same engine as the Camry). Mainly because we don’t have a Top-Tier gas station any where near us.

I’m suspect of the engine knock…Carbon Buildup in a fuel injection car is rare…And the engine knock associated with Carbon buildup is more like a ignition timing engine knock…

What I suspect you heard was valve clatter due to no oil in the valves because it drained down while sitting so long.

According to the dealer it was not valve clatter they had the engine running on several occasion during the week they had it.They called in the factory rep he told them to try the cleaner if it did not work they would have to go into the engine.The rep was there while the car was running??